N or NPK: to spread or not to spread?

03 September 2021

Spreading nitrogen (N) from mid-September onwards needs careful consideration. The growth response will have to justify the cost, and excess N not utilised by the plant is at risk of leaching. If you’re farming in an NVZ in England or Wales and within your N-max, you’re allowed up to 80 kg/ha N on grassland between the 15th September and the 31st October, with a maximum of 40 kg/ha N being allowed in any one application. Whereas in Scotland no nitrogen fertiliser may be applied from 15th September.

It's worth checking how much P & K has been applied to date, and if there’s any shortfall then apply a suitable compound NPK fertiliser like YaraMila 52 S or YaraMila NK SULPHUR to replenish this year’s P & K offtakes instead of N only. Under applying P or K this year only depletes soil fertility for next year and there is a clear relationship between good soil fertility and high grass dry matter production. So as tempting as it may seem to go with nitrogen only in this last application, we shouldn’t risk lowering soil fertility for next year.

Grass demand should dictate the N rate, but don’t forget to also consider soil conditions and the weather forecast. Take a paddock by paddock approach to spreading N rather than blanket spreading the entire grassland area. Depending on your demand for grass, apply 25 – 30 kg/ha N and earlier the better. Higher rates of N, or N applied in October, won’t be justified in most years.

Read more about grassland nutrition

Grow grass NOW to extend your autumn grazing

07 August 2021

From mid-September, daily grass growth will fall rapidly. After this point grass can quickly run out and either livestock performance declines or they will require housing to maintain performance. If we start to manage grass now, we can grow more grass over the coming weeks. This then allows us to build up a bank of grass for extending the grazing period and, if correctly managed, allows for an earlier turnout of livestock in the spring.

Grass DM yield response to Autumn applied fertiliser N

Grass grown now will remain leafy, albeit not as good as that grown earlier in the year. It will not require the same level of purchased feed to maintain a certain level of milk yield, or daily live weight gain, compared to feeding poorer quality forage indoors or set stocked grazing where there is poorer quality grass with lots of dead material at the base.

If we optimise grass growth over the coming weeks by applying YaraBela Nutri Booster and operating a rotational grazing system (even if it’s temporary fencing), we can save money and shorten the indoor period. This means that livestock will need to graze an area and then be moved onto a fresh area every 1-4 days, allowing the sward to recover and start growing again. The drier or ‘earlier’ parts of the farm should be grazed from mid-September and then closed off as the regrowth on these parts can be carried over the winter months for grazing first in the spring.

Read more about grassland nutrition

Fertiliser recommendations for grassland reseeds

Yara's grassland agronomist Philip Cosgrave talks about fertiliser recommendations for reseeded grassland to get new leys off to the best start.

How can I increase my soil carbon levels?

19 June 2021

Measuring carbon levels in the soil is becoming increasingly important with the development of financial incentives for carbon sequestration. The thought behind it is that an increased amount of carbon sequestered in soil should help to lower the amount of carbon in the atmosphere, with the added benefit of increasing soil quality.

Increasing soil carbon means carefully managing its inputs and losses. If the amount of carbon going into the soil exceeds the amount of carbon being lost from the soil, then, generally speaking, the amount of carbon stored in the soil should increase.

However, some soils can store more carbon than others. Soils that have higher clay contents can store more carbon than soils with less clay. That’s because clay particles physically protect organic matter making it harder for soil micro-organisms to make contact and decompose it. Sandy soils contain less clay, so it is easier for microbes to get to the organic matter and break it down, hence sands turnover carbon much quicker and usually can’t achieve higher stored carbon levels.

The main carbon inputs to soil are from plant material such as roots, residues, root exudates and animal manure. Plants capture carbon from the atmosphere and use it to grow. Carbon makes up the majority of the mass of the plant, and when plants are returned to the soil after being excreted or incorporated, the carbon they contain is added to the soil’s carbon store.

Read more about the soil analysis

Fertiliser recommendations for forage brassicas

Yara's grassland agronomist Philip Cosgrave talks about the basic nutrient requirements of forage brassicas together with fertiliser recommendations to get new crops off to the best start.

Grass mineral analysis – a useful management tool

12 June 2021

Grass mineral analysis can be a useful tool to check nutrient levels, both macro and micro-nutrients levels in grass swards. Silage samples are regularly tested for minerals, but it’s usually with a focus on animal nutrition rather than crop nutrition. So there is certainly more scope on grassland to utilise silage mineral analysis to improve yields and nutrient use efficiency.

During the winter a farmer asked me to have a look at his 1st cut silage mineral analysis report received back from the Yara Analytical Services lab which highlighted a couple of potential problems. Because it was a composite sample from a number of different fields, it warranted a closer look in the spring, so three silage fields were sampled in May, 10 days before harvest.

The three fields had received the same nutrients in the spring - a combination of slurry and YaraMila EXTRAGRASS (27-5-5+6%SO3). Nitrogen, phosphorus, potash, sulphur, calcium and magnesium were within the optimum range for two of the fields, while the report on the third field indicated that phosphate, potash, calcium and magnesium were deficient.

These three fields had the same history of manure applications, and the most recent soil analysis indicated good levels of soil phosphate and potash. The low soil pH (5.4) was the difference in the ‘deficient’ field. This makes sense, as soil pH affects nutrient availability. This again highlights the benefit of analysis and in particular the importance of acting on the results, especially correcting low soil pH.

Read more about the grass analysis suites

Nitrogen – what is the rule for grazing?

8 June 2021

As a rule of thumb we use the two units of nitrogen per day (2.5 kg N/ha/day) to guide nitrogen application rates for grass silage swards, but what about grazing? Where there is a high demand for grass on intensively stocked farms, then we should be aiming to apply 1 unit of nitrogen per day (1.25 kg N/ha/day), over the coming three months. So, if your rotation length is 21 days, then apply 21 units of nitrogen (26 kg N/ha), and aim for a total of 30-31 units of nitrogen per month (37.5 kg N/ha/month). If this seems low, remember there is nitrogen carryover from urine and dung from previous grazings.

For best results, use a nitrate-based nitrogen fertiliser, like YaraBela Nutri Booster. This CAN-based fertiliser with 5 % sulphur was specifically formulated for mid-season nitrogen applications. Nitrate based fertilisers are more reliable during the summer months. The added environmental benefit of using CAN based nitrogen products like YaraBela Nutri Booster is its very low ammonia emissions - even during the summer months.

If paddocks have a clover content of 20 – 25 %, then there is scope to stop nitrogen applications altogether from June onwards. Irish research has demonstrated that clover swards receiving 150 kg N/ha (120 units/acre) of nitrogen annually, had similar performance to perennial ryegrass swards receiving 150 kg N/ha (200 units/acre). Clover is a shallow-rooted species with around 15% of the root density of perennial ryegrass making it much less competitive for soil nutrients. Regular applications of a P and K compound like Yara Super PK throughout the growing season are necessary for high levels of clover productivity and biological N fixation.

Read more about the grassland rule

Fertilising second cut silage

18 May 2021

It’s fair to say, that first cut silage yields have been disappointing. It’s no wonder considering the growth we’ve had during April and early May. Some have ended up grazing fields that were intended for the first cut, so with this in mind and low silage stocks, a good second cut will be more important than ever to put tonnes in the pit for the winter ahead.

If adequately fertilised, and with favourable growing conditions these 2nd cuts crops are capable of 6 – 7 tonnes of fresh weight per acre, which isn’t far behind a good first cut. Slurry and fertiliser application rates are important considerations to make the most of second cut yield potential.

It’s best practice to apply fertiliser a week after the slurry has been applied. If no slurry is being applied, then spread the fertiliser within a couple of days of the first cut harvest or on closing up from grazing. It happens regularly that nutrients applications are delayed too long, which then results in lighter crops or crops needing a longer growing period, which in turn lowers silage quality.

New swards have excellent yield potential and respond to higher nitrogen (N) rates of up to 100 kg/ha (80 units/acre). Older swards with a high proportion of perennial ryegrass (PRG) can be fertilised to 90 kg/ha (72 units/acre) N and old meadow swards which don’t contain much PRG should receive 70 kg/ha (56 units/acre) N.

If there is no slurry applied or low volumes on account of the risk of slurry contaminating second cut grass at harvest, then make sure to use an NPKS fertiliser like YaraMila SILAGE BOOSTER.. Don’t forget sulphur on these 2nd cuts. 25 – 30 kg/ha (20 – 24 units/acre) of SO3 is enough.

Sulphur is an important nutrient, and it certainly merits using a fertiliser that contains sulphur on these second cuts. The response does vary according to soil type, regularity of manure applications and overwinter rainfall, but the majority of silage crops do respond to applications.

With over 90 % of silage samples analysed having very low selenium levels, there is also an opportunity to increase the selenium content of silage for the winter ahead by using fertiliser’s fortified with selenium like YaraMila SILAGE BOOSTER. This is most beneficial to pregnant cows and ewes.

A good second cut, requires a proactive approach to ensure these crops are optimally fertilised, so just slurry and straight N might not be the most cost-effective option in the long run, if we compare the cost of homegrown silage versus purchased feed on a dry matter basis

Finally, don’t delay applying slurry and fertiliser. The slurry should be applied immediately after the first cut is harvested and then apply the fertiliser 5 – 7 days later. If slurry isn’t being applied, then get the fertiliser out as soon as possible but it’s important to order what fertiliser is required and have it ready for spreading.

Read more about grass silage nutrition

Slurry for second cut silage

18 May 2021

If slurry is available, the amount needs to be evenly applied over the entire second cut silage area. What often happens is, too much is applied at the beginning before it’s realised there’s not enough in the tank, and then the application rates have to be reduced or even vice versa. We end up with parts of the field being undersupplied with nitrogen (N) and potassium (K).

Slurry needs to be applied as soon as the first cut has been harvested, and preferably by low emission spreading systems (LESS) like trailing shoe. On fields that are only now being closed up for silage after being grazed, then the grass needs to be well grazed down. Slurry is a great source of nutrients and reduces fertiliser costs, however, we don’t want the residues of this slurry ending up in the pit and causing issues. It really depends on how ‘watery’ or ‘thick’ the slurry is. Thick slurry would need to be applied in lower volumes for fear it mats the grass and doesn’t get washed off. Lower dry matter (DM) slurry or ‘watery’ slurry can be spread at higher rates.

The period of time between slurry application and a planned harvest will also dictate the slurry rate. If it’s less than 6 weeks then low volumes, and if it’s ‘thick’ slurry being spread by splash plate, then it might be better not to apply, and leave till later in the season.

Read more about grass silage nutrition

Reach that maize yield potential with foliar nutrition

06 May 2021

Maize has a high demand for nutrients due to its high yield potential. These high yields of 40+ tonnes/ha can only be achieved if the crop can access enough nutrients via its roots, and as the plant grows, through foliar applications.

Zinc and magnesium deficiencies are the two most widespread nutritional disorders in maize. Zinc is important for photosynthetic activity. Magnesium is essential for the early establishment of the plant. A deficiency is reflected in reduced crop yield at harvest.

Phosphorus and potash are primary nutrients, however, many soils have not got the capacity to deliver an adequate supply. Where phosphate availability is reduced because of soil pH or where its uptake is impaired due to dry soil conditions, foliar phosphate will help. It is translocated from the leaf to the roots very effectively, maintaining root development.
One or more of the above is often deficient in the growing maize plant. This nutritional shortage is particularly important as the plant reaches the 4 to 5 leaf stage as it is now that yield is being set. Maize stressed at this point can result in tall, thin plants, with poor root systems and reduced leaf area. Reduced leaf area captures less light, resulting in lower yields.
To overcome the risk of nutrient deficiency, apply foliar nutrients at the 4 to 5 leaf stage. YaraVita Maize Boost is specifically formulated for foliar applications on maize. It will deliver a high concentration of phosphate, zinc, magnesium and potash to maximise maize yield and quality this harvest.

Read more about maize foliar nutrition

Cold and dry April hits grass growth rates

30 April 2021

It’s likely that 1st cuts will be lighter, so if you’re looking to cut high-quality silage stick as close to your planned cutting date. Hopefully, we can make up this yield loss in subsequent cuts, but we won’t be able to make up for the higher costs of supplementing poorer quality silage.

On farms where 1st cuts are only being closed up, then use a nitrate-based fertiliser. If slurry hasn’t been applied then definitely go with an NPKS product like YaraMila Silage Booster to maximise silage yields. Potash (K) is a really important nutrient for silage and a low K supply can really hit silage yields. For every kg of K we apply per ha, we see a return of 20 – 30 kg of silage. If 22 – 33 m3/ha (2,000 – 3,000 gallons/acre) of cattle slurry is applied, then an N + S product like YaraBela Nutri Booster is adequate.

To calculate the N required for a 1st cut that is only being closed-up for silage, then count the days between closing-up and a planned cutting date. Subtract 5 days from this number, and then multiply by 2.5 to give the kg/ha of N required (multiply by 2 to give units/acre). The N in any cattle slurry (0.9 kg/m3 or 8 unit/1,000 gal), along with 20 % of any fertiliser N applied earlier for grazing, should be deducted from the N requirement of the silage crop to give the fertiliser N rate.

Read more about managing second cut silage

Grassland agronomy advice

The latest grassland fertiliser and nutrition advice from the Yara agronomists.

 Four steps to successful reseeding

09 April 2021

 

Benefit of reseeding on net rofit

Step 1: Identify poorly performing paddocks.

Step 2: assess their content of desirable grasses. If this is less than 60% consider re-seeding. Annual meadow grass and other weed grasses produce lower yields, poorer feed quality and do not respond well to applied nutrients. Yield will be reduced by 1 % for every 1 % in weed ground cover.

Step 3: Take a soil test and act on the results. Before you start, be sure to complete this step. On mineral soils, the optimum pH for grass is 6.3. Failing to correct pH will severely impact the success of your reseed. Choose only varieties from the Recommended Grass and Clover Lists (RGCL) and pick those that suit your particular farm.

Step 4: Provide new swards with the correct nutrients at sowing. Failure to do so will hinder the success of the ley. Where clover isn’t included, and the soil P & K index is 2, then use 330 kg/ha YaraMila ACTYVA S (16-15-15 + 6.5% SO3) at establishment. New leys have a greater requirement for phosphate to help with root development and a lower requirement for nitrogen.

My Top Tips: Weeks 4-6 (post-emergence) apply herbicide to prevent weeds competing for nutrients and space. Graze lightly with youngstock or sheep, as soon as the new plants don’t pull out of the ground, which is usually when grass height is at 6 - 7 cm or at the two-leaf stage to promote new shoots, and thus the long term productivity of your new sward.

See our new sown grass fertiliser programme

Purchase quality compound fertiliser

02 April 2021

At this stage, most 1st cut fertiliser applications are completed, but are you confident that your target fertiliser rate was evenly applied? Yara has demonstrated how, over 24 metres, the physical quality of a fertiliser influences the yield and quality of a grass crop.

Yara has looked at this effect by comparing YaraMila Extragrass (27-5-5+6%SO3) with a blended 27-5-5+S. The target rate for both products was 500kg/ha and the spreader settings were changed for each product on testing. The YaraMila product achieved the target rate across the whole bout width; however the application rate for the blended product varied between 400 to 648kg/ha.

We then analysed separately each of the 23 trays from the blended product, to determine the actual NPK+S content. Because the YaraMila product is a compound, we know that the product in each tray contained 27% N, 5% P2O5, 5% K2O and 6% SO3. The blended product had a variation in N across the bout width of between 91kg and 160kg, for P the variation was 10 to 19kg and for the K it was 34 – 59kg/ha. The target was 135kg, 25kg and 25kg for N, P2O5, K2O respectively.

Accounting only for unevenness of the N, in this blend, compared to the YaraMila Extragrass, there was a yield loss of nearly 400kg/ha of grass dry matter. That’s a loss of nearly 1.5 tonnes of silage, worth around £30 per ha.

Don’t take the chance, use a quality compound fertiliser.

Read more about YaraMila

The first cut is the cheapest

11 March 2021

With 1st cut fertiliser applications underway, it’s important to remember that 1st cut silage is the most economical cut to grow. For all cuts the variable costs are similar. Due to the high yield of the 1st cut, it is this forage that achieves a lower cost/tonne of dry matter ensiled. The nutrition given to these crops this spring will be the main driver of how well they perform come harvest.

What nutrients are required? Slurry is available on most farms and should preferably be applied by low emission equipment. It minimises nitrogen (N) losses from ammonia volatilisation, leaving more N in the soil for the crop. 1,000 gallons/acre of cattle slurry, contributes 7 units of N if applied by splash plate (or 9.5 units if applied by trailing shoe/trailing hose). After accounting for the N in the slurry, the mineral N rate should be calculated to ensure that the crop receives a total N rate of 100 units/acre.

At least 70 units of potash should be applied for 1st cut, unless the soil index is 3 or above. A little more can be applied if the soil index is 0 or 1. If this potash rate is not supplied via slurry then apply in fertiliser. 1,000 gallons/acre of cattle slurry contains 21 units of potash. All 1st cut silage crops should routinely receive 25 – 30 units of sulphur. Where an NPKS fertiliser is required, then YaraMila Silage Booster ticks all the boxes.

See more information on grassland nutrition

The big questions this spring

26 February 2021

How long should I leave between applications of fertiliser nitrogen (N) and slurry?, is one of the questions I am most often asked. Slurry applied on fertiliser N creates ideal conditions for denitrification, i.e., anaerobic conditions and high carbon compounds. It is recommended to leave 7 days before or after slurry spreading for application. There’s always some confusion around lime applications and urea. If lime is applied, then urea shouldn’t be spread for at least 3 months afterwards. The lime increases the soil pH which increases the rate of volatilisation of ammonia. Lime can be spread 10 days after urea applications.

I’m also asked: What are the sulphur levels in slurry and are they enough for a 1st cut silage? If 2,000 gallons/acre of cattle slurry (22 m3/ha) was applied this spring, it’s estimated to contain 6 units/acre (7 kg/ha) of crop available sulphur. This is not enough, as a decent 1st cut will remove 28 - 32 units/acre (35 – 40 kg/ha). Sulphur in autumn slurry applications may be lost via overwinter leaching. Some of the available crop sulphur (sulphate) in slurry is also lost during storage, as anaerobic storage conditions lead to the conversion of sulphate to hydrogen sulphide gas.

Phosphate is another topic. The 16 units/acre (20 kg/ha) of phosphate on my grazing area, when should I apply? My advice is to spread it over two or three applications, with two preferably in the spring and then another in early June.

See more information on grassland nutrition

Lime your grassland and reduce your greenhouse gas emissions

12 February 2021

Research in Ireland has shown that by liming to increasing soil pH there also followed a significant reduction of N2O emissions and increased grassland productivity. Liming is well known as an agronomic measure to ameliorate acidic soils and maintain soil pH at the optimum level for high crop productivity. Liming increases the activity of soil microbes and the availability of nutrients, most notably phosphate, leading to improved plant growth. This research could be used to further support an increase in the optimum soil pH for grassland on farms with high grass yields.

The soil at the trial site was classified as acidic, with a pH of 5, but liming over 10 years resulted in soil pH ranging from 5.0 to 6.9. Increasing soil pH by liming resulted in a significant reduction of N2O emissions and increased grassland productivity compared to the un-limed plots under the same management and nitrogen fertiliser regime. The degree of reduction in N2O emissions mainly depended on the amount of lime applied across the experimental period. When soil pH was increased to 6.9, N2O emissions were reduced by 39% compared to the control soil pH of 5.0. The long-term results in terms of grass yield showed that the highest yields were achieved when liming was combined with regular phosphate application. Plots limed to pH higher than 6 had 0.5 t/ha higher dry-matter yields, while the yields in limed plots with optimal P content had 1.5 t/ha higher yields on average compared to un-limed soils with low P fertility.

See more information on grassland nutrition

Spring N for grazing - what’s your plan?

12 January 2021

One of the most important factors affecting spring grass growth on farms is the timing and quantity of the first spring nitrogen (N) fertiliser application. Early spring grass for grazing is extremely valuable. Therefore however modest any increase in grass growth might be, it can be a big help to balance the overall feed requirement of livestock. Grass requires more N to grow, so sulphur (and potentially phosphate and potash) are also required.  

There’s always an element of debate around the right approach to spring N management. As a rule of thumb, the timing of the first N application should coincide with soil temperatures reaching 5 - 6oC. If you’re using a soil thermometer for the first time, my advice is it make sure you insert it 10 cm’s into the ground. You can also check the Grasscheck GB website for soil temperatures. Of course, a favourable weather forecast and good field conditions are also necessary when deciding when to spread.

For your first N application, we recommend using a product with sulphur such as YaraBela Nutri Booster at a rate of 20 - 23 units N/acre. The second application should aim to deliver 40 - 45 units and be timed to take advantage of improving growing conditions in early April. These rates are appropriate for newer swards with high perennial ryegrass content. On less intensively stocked farms or on swards which will be less responsive to N, then the above rates should be scaled back by 25%.

See more information on grassland nutrition

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Soil health is vital: Test it, review it and take action

10 December 2020

At some stage, over the next couple of months, you should plan to do some soil testing if you haven’t done so already. Once you have the results don’t file them in a drawer. Review them and use them to put together a nutrient management plan (NMP) for 2021. An NMP is really about prioritising how we use organic and mineral nutrients on the farm in the most cost-effective way possible.

Too often organic manures are applied on the same parts of the farm, year after year. There are plenty of reasons why this is done, but it’s not maximising the potential value of this valuable resource. Using umbilical spreading systems may be an option to target other areas of the farm. Target cattle slurry at low K index soils as it’s a cost-effective potash source.

Intensively stocked grassland farms, should consider soil testing more regularly. By soil testing every 1 – 3 years you’re in a better position to monitor soil fertility trends. Fertiliser recommendations are not an exact science, hence soil testing more frequently together with measuring grass yields will help you fine-tune your NMP for every paddock or field on your farm.

Remember, grass requires a continuous and balanced nutrient supply from the soil to achieve its production potential. If a farm is regularly soil testing, say every three years, then the £1 ha/year cost is money well spent.

See more information on soil testing and analysis

3-cut vs 4-cut Silage System: Does it make a difference?

27 November 2020

The quality of grass silage fed to dairy cows is an important factor in cow performance and margin-over-feed cost. Silage digestibility (D-value) declines by an average of 3.3% for each week delay in harvest. Hence the move by dairy farmers to cut earlier and more frequently. A recent Northern Irish study examined cow performance and the whole system impact of offering silages produced within either a 3 or 4-cut system.

Total silage dry matter (DM) yields for the 3 and 4-cut system were 13.4 t DM/ha and 12.3 t DM/ha respectively. The average DM of the 3-cut system was 31.9% and 34.4% for the 4-cut system. The average metabolizable energy (MJ/kg DM) was 10.7 and 11.3, and average protein (% DM) was 14.3 and 16.4 for the 3 and 4-cut system respectively.

Cows on the 4-cut system had higher silage intakes (+9.5%), produced more milk (+6.4%) with higher milk protein (+2.1%) but slightly lower fat content (-2.4%). Silage production costs were calculated as £114 and £135 t/DM for the 3 and 4-cut system respectively. This includes a land charge, reseeding cost and a contractor for harvesting.

Total feed costs were 23 pence/cow/day higher with the 4-cut system, but the value of milk produced was 71 pence/cow/day higher. The margin-over-feed cost was 48 pence/cow/day higher for the 4-cut system. For a 100 cow herd over a 180 day winter period, the 4-cut system resulted in a £8,640 increase in margin-over-feed costs.

Multi-cut silage systems may not suit every farm, but bring the potential to lower feed costs, improve milk output and make dairy farms more self-reliant.

Read more on grassland nutrition

 

Green Ammonia – What is it and Why?

27 November 2020

Yara announced its plan to produce Green Ammonia earlier in the year but what does this actually mean?

In order to produce ammonium nitrate (AN) fertilisers, ammonia is mixed with nitric acid to produce a liquid ammonium nitrate solution, this then goes on to produce the prills or granules that you’d recognise as fertiliser. The ammonia that is used for this process is produced with hydrogen gas from fossil fuels, mainly natural gas (methane), and therefore is classed as ‘brown’ ammonia due to its use of natural resources.

Green Ammonia is produced in a different way. H2O undergoes electrolysis, which is powered by renewable energy sources such as wind and solar power, in order to get the required hydrogen gas. Nitrogen is obtained from the atmosphere (which is 78% nitrogen gas) and two undergo the Haber-Bosch process. The end result is Green Ammonia, made from renewable sources. Unlike in the traditional ‘brown’ ammonia method, there is zero CO2 ‘waste’, therefore there is only a very low carbon footprint associated with Green Ammonia.

This is increasingly important as consumers want to know the carbon footprint of their purchases and it is thought that all food items will show a carbon footprint value in the near future. Every process needs to be sustainable and have as little impact on climate change as possible. With ammonia being the second-most-widely produced commodity chemical globally, (annual production volume of over 180 million tonnes) this new method would make a massive impact worldwide.

Read more about green ammonia

Grass YEN 2020 results review

13 November 2020

Grass YEN, the industry-science platform had its end of year meeting earlier in October. Yara was once again co-sponsor of the event, and I would like to take this opportunity to thank the five farmers that we sponsored for their time and energy in participating in this year’s competition.

There were 23 silage crops entered in this year’s competition. The yield gap between 1st cuts and 2nd cuts was narrower as you would expect with the drought affecting 1st cut yields. Average 1st cut dry matter (DM) yields were 5,385 kg/ha, ranging from 3,502 – 9,014 kg/ha. Average 2nd cut DM yields were 4,602 kg/ha, and ranged from 3,218 – 8,754 kg/ha. DM yields for 3rd cuts averaged 3,028 kg/ha.

Nutrient offtakes is always an interesting aspect of Grass YEN, where grass samples from each grass crop are analysed for their mineral content and from this offtakes are calculated. The average offtakes for each tonne of DM yield across all crops was 21kg of N, 7kg of P2O5, 31kg of K2O and 5kg of SO3. With the highest yielding cuts taking off over 300kg N/ha, >400kg/ha K2O, >50kg/ha SO3.

Looking at the tissue concentrations of the crops sampled, 74% of the crops were considered sulphur deficient. If we want to improve nutrient use efficiency on farms, the use and rate of sulphur applications on silage crops needs careful consideration and could be an easy win to reduce nutrient loses, increase yields and improve silage quality.

In the battle to reduce our carbon footprint, could green ammonia be the hero?

01 October 2020

Ammonia is a gas that is widely used to make nitrogen fertilisers. Green ammonia production is where the process of making ammonia is 100% renewable and carbon-free. One way of making green ammonia is by using hydrogen from water electrolysis and nitrogen separated from the air. These are then fed into the Haber process (also known as Haber-Bosch), all powered by sustainable electricity. In the Haber process, hydrogen and nitrogen are reacted together at high temperatures and pressures to produce ammonia (NH3).

Reducing the amount of carbon dioxide produced during the ammonia manufacturing process is critical to achieving net-zero targets by 2050. The best way to reduce carbon emissions when making ammonia is to use low-carbon hydrogen. Green hydrogen is produced using water electrolysis to generate hydrogen and oxygen, and the availability of sufficient green energy limits the production capacity of green hydrogen.

A consequence of decarbonised ammonia production is you can’t produce urea. Because urea is made by combining ammonia and the carbon dioxide (CO2) released in the earlier process where hydrogen is split from the carbon source (usually natural gas) to provide the hydrogen in ammonia (NH3) production. So it’s unlikely urea can be part of a decarbonised food chain.

It’s Yara’s goal to decarbonise fertiliser production, but it will require significant ongoing investment in R & D and production capacity. It’s interesting to note that when Yara first began producing nitrogen fertiliser in Norway, back in 1905, the process was carbon-free! The energy source back then was hydro-electricity.

Nitrogen: to spread or not to spread?

04 September 2020

Spreading nitrogen (N) from mid-September onwards needs careful consideration. The growth response will have to justify the cost, and excess or unused soil nitrate should be minimised as we approach winter as it constitutes a risk to water quality. If you’re farming in an NVZ, then you’re allowed up to 80 kg/ha of mineral nitrogen on grassland between the 15th September and the 31st October, with a maximum of 40 kg/ha of N being allowed in any one application.

Preferably N applications should take place at a time when grass growth is sufficient to utilise it. Teagasc research on autumn applied N has shown that 30 kg/ha of N applied on the 1st of August, 1st September and 1st of October gave a grass dry matter (DM) response of 27 kg, 19 kg and 10 kg respectively, for each kg of N applied. If we assume that this grass DM contains 3% N, then our apparent N recovery rate was 80% for August, dropping to 30% for October.

It is important that any N applications take into account the requirement for grass, but don’t forget to also consider your soil and weather. I advise taking a paddock by paddock approach to spreading N rather than blanket spreading the entire grassland area. Depending on your demand for grass, apply from 20 – 25 kg N/ha, and preferably by mid-September. Higher rates of N, or N applied in October, won’t be justified in most years.

Read more on grassland nutrition

 

Grass and forage agronomy and fertiliser advice
Grass and forage agronomy and fertiliser advice

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Fertiliser advice for short term leys and hybrid brassicas

14 August 2020

Adequate fertiliser is essential to obtain the maximum yields that short term leys and hybrid brassicas are capable of producing. In general these crops are being sown after a cereal crop, and therefore soil nitrogen supply (SNS) is likely to be low.

For temporary leys following cereals, we recommend 312 kg/ha of YaraMila Actyva S (16-15-15 + 6.5% SO3) to deliver the necessary NPKS for establishment. This true uniform compound fertiliser ensures a maximum number of phosphate landing sites. The seedlings’ access to phosphate is particularly important for root development and tillering.

Remember that there’s 7.5 kg/ha of nitrogen in every 1 cm of grass growth. We would expect Italian ryegrass or Westerwolds to grow to a minimum height of 10 cm by the end of October, therefore requiring 75 kg of N. If we apply 50 kg of N from the bag, there will be enough soil residual N to provide the remaining.

Hybrid brassicas, such as Redstart and Interval, may still be drilled into late August. They have similar nutrient requirements to those of forage rape and stubble turnips. We recommend 400 kg/ha of YaraMila Silage Booster (20-4.5-14.5 + 7.5% SO3 + Se) to deliver the necessary NPKS to grow these crops on fields with an SNS of 0 or 1 and a P & K index of 2.

It is vital to get these crops off to a good start, so placing the fertiliser in the seedbed will help to establish strong healthy plants.

Read more on fertilising short term leys

 

Grow grass now to extend your autumn grazing

31 July 2020

From mid-September daily grass growth will fall rapidly. After this point grass can quickly run out and either livestock performance declines or they will require housing to maintain performance. If we start to manage grass now, we can grow more grass over the coming weeks. This then allows us to build up a bank of grass for extending the grazing period and, if correctly managed, allows for earlier turnout of livestock in the spring.

Grass grown now will remain leafy, albeit not as good as leafy grass grown earlier in the year. It will not require the same level of purchased feed to maintain a certain level of milk yield, or daily liveweight gain, compared to feeding poorer quality forage indoors or set stocked grazing where there is poorer quality grass with lots of dead material at the base.

Grass yield response to autumn applied nitrogen

If we optimise grass growth over the coming weeks by applying nitrogen and sulphur now and operating a rotational grazing system (even if it’s temporary fencing) then we can save money and shorten the indoor period. This means that livestock will need to graze an area and then be moved onto a fresh area every 1-4 days, allowing the sward to recover and start growing again. The drier or ‘earlier’ parts of the farm should be grazed from mid-September and then closed off as the regrowth on these parts can be carried over the winter months for grazing first in the spring.

Read more grassland fertiliser advice

Soil fertility in grass based systems - what can we learn from Ireland

17 July 2020

Adopting Controlled Traffic Farming (CTF) could help reduce soil compaction risk and boost yields by up to 10.5%, while also reducing nitrous oxide emissions.

In Yara’s recent grassland webinar, we were joined by Mark Plunkett, a specialist in soil and plant nutrition with Teagasc in Ireland. Mark reviewed current soil fertility trends on Irish farms. He then went on to explain why Teagasc have focused considerable effort to demonstrate why it’s worth improving soil pH, phosphate (P) and potash (K) levels to keep farms competitive.

On Irish dairy farms the trend over the last 10 years has been positive for soil fertility. This information is collated annually from Irish soil test result records. Soil pH has improved on these farms, and currently 59% of soil samples have a pH of 6.2 or above, up from 25%, 10 years ago. The optimum soil pH for grassland in Ireland is 6.2 – 6.5. Half of soil samples currently tested are at the optimum or higher for P, and 59% were at the optimum or higher for K. Crucially, the number of soil samples at the optimum or higher for pH, P and K has doubled in the last 10 years. It now stands at 21%.

Did you know up to 15% of nitrogen can be wasted if soil P is below par? As Mark discussed, using research and on-farm data demonstrates the importance of optimising soil fertility, to grow more grass cheaply and sustainably. Mark signed off with some very simple advice: soil sample regularly and follow a fertiliser plan.

Listen to the latest grassland webinar

Controlled traffic farming

23 June 2020

Adopting Controlled Traffic Farming (CTF) could help reduce soil compaction risk and boost yields by up to 10.5%, while also reducing nitrous oxide emissions.

Limiting compaction at silage-making

Grassland farmers could benefit from adopting an ‘arable mindset’ and controlling the movements of machinery across fields as a means of limiting compaction and maximising grass yields.
This is according to Dr Paul Hargreaves, grassland researcher for SRUC, who has just completed a three-year study looking at CTF on silage ground. His results show grassland farmers could expect a yield increase of 8.5-10.5% by following a CTF system, while nitrogen use efficiency will also be improved.

Rather than driving anywhere on a field, CTF means machines follow set wheel marks which run parallel to the line of trajection and then around the headland. “It’s about trying to control the movements of machinery around a field to limit the area they cover and running all machinery along similar wheelings. It’s trying to think of grass as an arable crop,” says Dr Hargreaves. SRUC trial work found that about 83% of a field cut three times using a forage harvester, with slurry applied, will be covered in wheelings on a traditional system. These wheelings will suffer from soil compaction and therefore reduced yields. On a CTF system, the area covered in wheelings will reduce to about 19%.

SRUC trial results

The three-year trial at SRUC looked at long-term performance of a perennial ryegrass and red clover ley, which was established at the start of the trial. They looked at different nitrogen application rates and compared CTF and non-CTF. In the non-CTF strips, machinery was driven wherever they wanted. On the CTF strips, the fertiliser and slurry spreaders, mower, tedder, rake and forager, all followed a nine-metre working width.

Dr Hargreaves was keen to see the damage caused to the wheelings on the CTF system over the three years. Although there was an increase in soil bulk density and reduced porosity, he says there was ‘limited damage’ and no issues with water run-off from these areas.
“So far, we’ve seen a reduction in yield on those wheelings and the red clover has disappeared entirely, but the perennial ryegrass is still there,” he says.

He believes this is not a huge issue on a three-year red clover ley as the issue could be addressed as part of reseeding. If a farm was doing CTF on a five to six-year perennial ryegrass and red clover ley, some kind of mitigation work would be needed on these wheelings, such as sward lifting. Wheelings would then need to be shifted across in the next season so improvement work was not compromised.

Overall, Dr Hargreaves says focusing traffic in set areas helps minimise overall field damage.

“You are reducing the structural damage to soils so you are potentially maintaining drainage and the quality of the soil. And you know where the damage is on the field so you can deal with it specifically,” he says.

Why is compaction a problem?

  • Limiting soil compaction should form part of an holistic approach to soil management which should also look at pH and maintaining key nutrients such as potash and phosphate. There are some key reasons why compaction should be avoided:
    Prevents water infiltration – resulting in wet soils which take longer to drain.
  • Reduces soil pore spaces – so earth worms can’t do their job. Oxygen needs to get into the soils and carbon dioxide needs to escape. This is compromised if soils are compacted.
  • Reduces nitrogen utilisation – anaerobic soils will reduce the mineralisation of key nutrients such as nitrogen.
  • Increases nitrous oxide production (a greenhouse gas) – this gas is a product of denitrification, a biological process by which some nitrate in the soil is reduced to nitrous oxide. The rate of denitrification is increased in compacted soils, because of the lack of air as they’re denser and wetter for longer.
  • Reduces nutrient availability – such as phosphate.

Operating Controlled Traffic Farming

To operate CTF, Dr Hargreaves suggests thinking about the following:

What is the smallest working width of all your machinery?

If your smallest working width is nine metres, all equipment needs to work within this. This includes the slurry spreader, tedder and mower, etc. This means machinery will have to work along three-metre-wide tyre tracks in the field.

Split up fields

Divide the width of each field by the working width of your machinery. If a field is 135 metres wide and your smallest working width is nine, split it into 15 lines. If you end up travelling more on certain areas of the field, make a note of it and target soil improvement work in this area.

Use technology

Dr Hargreaves believes GPS and auto-steering technology is essential to do CTF properly. However, as a minimum he thinks GPS is essential. This will increase accuracy.
“Newer tractors being sold and equipment used by contractors often have GPS. This technology is becoming increasingly common place so it could be a case of just using the technology you’ve already got,” he says.

Use marker posts

If technology is not an option, consider using sight posts or positions in the field so machinery is driven in a particular route. All individual tractor drivers will need to pay care and attention.

Pay attention during carting

The distance between the forage harvester and silage trailers will increase with CTF – potentially to
six metres. This means the team will have to work steadily. Also, consider using high-sided trailers and not filling trailers all the way to the top.

Read more on the benefits of CTF

Keep the pedal to the metal

22 June 2020

With 1st cuts at below average, particularly those cut in the latter half of May, and very slow 2nd cut regrowth, we may be feeling slightly nervy when looking at our silage pits. Grass growth rates are well back on last year, so we’ll need some good growth in the months ahead to build up silage stocks. The rain has helped lower soil moisture deficits, but they’re still restricting grass growth.

On intensive grazing farms where growth rates have responded to rain, maintaining a 21 day rotation and keeping residuals of 4 cm is crucial. If paddocks have gone stemmy, pre-mow to get them back on track, alternatively target these for silage. Heavy covers of > 3,000 kg should be cut as surplus bales, and maintain grass growth by keeping N + S applications up-to-date. Slurry should be applied where silage/surplus bales are taken off. Remember to keep ammonia emissions as low as possible by using low emission spreading equipment such as trailing shoe. If slurry is not available, then apply a NPKS quality compound fertiliser such as YaraMila Silage Booster to replace P and high K off-take from taking surplus bales.

For N applications on a 21 day grazing rotation, 1 – 1.2 units N/acre/day is sufficient. Between the release of mineralised N from soil organic matter following the rain, together with residual N from fertiliser applications that hadn’t been used by the grass due to the drought, means there’s quite a large pool of nitrate available in the soil to meet the demands of increased growth rates. So, no benefit in over-applying N.

With 1st cuts below par and 2nd cuts delayed, it might be prudent to look for alternative ways to put tonnes of silage in the pit. Buying standing crops of spring barley for whole crop for instance or direct drilling Westerwolds into stubble for a late silage cut can make up some lost tonnes. Alternatively, drill a forage brassica crop into stubble for grazing in Autumn/Winter.

Read more on increasing grassland yield

Hot topics: New season nitrogen, boosting maize and cow health

08 June 2020

New season nitrogen – do your research

Whether it’s new season or this season’s nitrogen requirements you might be considering to purchase, don’t end up with fertiliser that’s not fit for purpose. This can mean a wrong grade or choosing a product that looks good on price but doesn’t have the spreading quality characteristics. The wrong grade could mean purchasing straight nitrogen instead of nitrogen and sulphur. For quality, some nitrogen products look good but flatter to deceive as the granules look big but they’re soft, so shatter easily on the vanes of the spreader. So, caveat emptor!

Read more on nitrogen and sulphur

A nutritional boost for maize

Maize crops are at an important stage right now and nutrition is really important for these crops as they undergo rapid growth and development. With the weather we’ve had, these crops need all the help they can get.
A foliar feed would be beneficial, either as a standalone application or in conjunction with a planned herbicide. YaraVita MAIZE BOOST is specifically formulated for foliar applications on maize and contains magnesium and zinc, the two most widespread nutritional deficiencies seen in maize. It also contains phosphate and potash, which may be limited in these dry soil conditions.

Read more on forage maize nutrition

Heathy grass for a healthy herd

Finally, keep up with P & K applications for grazing. The phosphate keeps levels in grazed grass topped up, which is particularly important in dairy herds. While potash applications where necessary, will help drought tolerance. Use a compound NPKS product like YaraMila STOCK BOOSTER S (25-5-5+5% SO3+Se), which provides the full gambit of nutrients to grow more grass this summer.

Read more on the benefits of selenium

Reach that maize yield potential with foliar nutrition

05 May 2020

Maize has a high demand for nutrients due to its high yield potential. These high yields of 40+ tonnes/ha can only be achieved if the crop can access enough nutrients via its roots, and as the plant grows, through foliar applications.

Zinc and magnesium deficiencies are the two most widespread nutritional disorders in maize. Zinc is important for photosynthetic activity. Magnesium is essential for the early establishment of the plant. A deficiency is reflected in reduced crop yield at harvest.

Phosphorus and potash are primary nutrients, however many soils have not got the capacity to deliver an adequate supply. Where phosphate availability is reduced because of soil pH or where its uptake is impaired due to dry soil conditions, foliar phosphate will help. It is translocated from the leaf to the roots very effectively, maintaining root development.

One or more of the above is often deficient in the growing maize plant. This nutritional shortage is particularly important as the plant reaches the 4 to 5 leaf stage as it is now that yield is being set. Maize stressed at this point can result in tall, thin plants, with poor root systems and reduced leaf area. Reduced leaf area captures less light, resulting in lower yields.

To overcome the risk of nutrient deficiency apply foliar nutrients at the 4 to 5 leaf stage. YaraVita MAIZE BOOST is specifically formulated for foliar applications on maize. It will deliver a high concentration of phosphate, zinc, magnesium and potash to maximise maize yield and quality this harvest.

Read more on forage maize nutrition

 Four steps to successful reseeding

24 June 2020

 

Benefit of reseeding on net rofit

Step 1 : Identify poorly performing paddocks.

Step 2 : assess their content of desirable grasses. If this is less than 60% consider re-seeding. Annual meadow grass and other weed grasses produce lower yields, poorer feed quality and do not respond well to applied nutrients. Yield will be reduced by 1 % for every 1 % in weed ground cover.

Step 3: Take a soil test and act on the results. Before you start, be sure to complete this step. On mineral soils the optimum pH for grass is 6.3. Failing to correct pH will severely impact the success of your reseed. Choose only varieties from the Recommended Grass and Clover Lists (RGCL) and pick those that suit your particular farm.

Step 4: Provide new swards with the correct nutrients at sowing. Failure to do so will hinder the success of the ley. Where clover isn’t included, and the soil P & K index is 2, then use 330 kg/ha YaraMila ACTYVA S (16-15-15 + 6.5% SO3) at establishment. New leys have a greater requirement for phosphate to help with root development, and a lower requirement for nitrogen.

My Top Tips: Weeks 4-6 (post-emergence) apply herbicide to prevent weeds competing for nutrients and space. Graze lightly with youngstock or sheep, as soon as the new plants don’t pull out of the ground, which is usually when grass height is at 6 - 7 cm or at the two leaf stage to promote new shoots, and thus the long term productivity of your new sward.

See our new sown grass fertiliser programme

Purchase quality compound fertiliser - it pays every time

04 April 2020

At this stage, most 1st cut fertiliser applications are completed, but are you confident that your target fertiliser rate was evenly applied? Yara has demonstrated how, over 24 metres, the physical quality of a fertiliser influences the yield and quality of a grass crop.

Yara has looked at this effect by comparing YaraMila Extra Grass (27-5-5+S) with a blended 27-5-5+S. The target rate for both products was 500kg/ha and the spreader settings were changed for each product on testing. The YaraMila product achieved the target rate across the whole bout width; however the application rate for the blended product varied between 400 to 648kg/ha.

We then analysed separately each of the 23 trays from the blended product, to determine the actual NPK+S content. Because the YaraMila product is a compound, we know that the product in each tray contained 27% N, 5% P and 5% K. The blended product had a variation in N across the bout width of between 91kg and 160kg, for P the variation was 10 to 19kg and for the K it was 34 – 59kg/ha. The target was 135kg, 25kg and 25kg for N, P and K respectively. Accounting only for unevenness of the N, in this blend, compared to the YaraMila Extra Grass, there was a yield loss of nearly 400kg/ha of grass dry matter as a result of the poor spreading pattern of the N. This equates to 1.5 tonnes/ha of silage which, based on barley and rapeseed meal, would have a replacement value of £54.

Don’t take the chance, use a quality compound fertiliser

Read more on YaraMila compound fertiliser

Quality grass silage starts with good crop nutrition

12 March 2020

To understand the difference that making good quality grass silage can have on a dairy farm, we can compare the cost of achieving similar levels of milk output by balancing a diet using either a good or poorer quality silage.

My following calculations are based on a 120 cow herd producing 9,000 litre/cow, housed all year round with the forage component split 25% maize and 75% grass silage. A 30 litre cow requires 10.85kg of concentrate to achieve production using poorer silage, where as a cow fed the better silage requires 7.54kg daily. This additional feed saving would translate into £32,000 with a potential additional increase in £13,000 of improved milk yield if cows were fed the better grass silage.

The feed efficiency translated from 0.35kg/litre to 0.24kg/litre between both forages, with a purchased feed cost saving of 3.19ppl using better forage. If we incorporated the forage cost, there would be a 2.43ppl difference between the diets. This difference is less than the purchased feed cost because we are gaining more milk from forage and so must feed more forage per cow.

The first step to making quality silage, is providing the right crop nutrition. If slurry has been applied, the nutrients should be accounted for in this and the balance should be supplied using a quality NPKS compound like YaraMila Silage Booster or if N+S only is required then use a product like YaraBela Nutri Booster.

See our silage fertiliser programmes

Soil phosphorus levels impact greenhouse gas emissions

12 March 2020

The role of soil fertility in mitigating Greenhouse Gas emissions has up to now been based on improving nutrient use efficiency. For example, soils at the correct soil pH can utilise soil phosphorus more efficiently. Microbial breakdown (mineralisation) of organic matter into plant available nutrients is at its highest when soils are at their optimum pH. However, new research seems to show that soil phosphorus levels have a direct effect on soil nitrous oxide (N2O) gas emissions on permanent grassland. N2O is a very potent Greenhouse gas, and hence the importance of this research.

It is thought that certain soil microbial populations that are more dominant in low soil phosphorus situations produce more N2O. With increasing soil phosphorus levels these microbes become less dominant resulting in lower N2O emissions. These low nutrient soils are more fungi dominated, and these fungi lack a particular enzyme which predisposes them to producing more N2O. It is very welcome that this research adds another positive dimension to the existing body of knowledge that supports the key role that soil fertility plays in the future sustainability of grass-based production systems.

With the continuing poor soil conditions, very little fertiliser has been applied. So, for those with no fertiliser in the yard, order your fertiliser now. Don’t wait until field conditions are improved to order. Those that wait, may be faced with delayed deliveries if lots of farmers order at the one time.

Read about planning spring phosphate applications for grass

Nutrient watch – advice for spring fertiliser and slurry applications

14 February 2020

Daily grass growth rates are still low, so not much nitrogen (N) is required at this stage. Only apply if soil temperatures are at 5OC and above. If soil conditions are too wet or frozen, then delay application until they improve. Early fertiliser applications are appropriate on drier soils with productive PRG swards which respond to early N applications and allow early grazing. Depending on livestock demand, apply up to 30 kg/ha (24 units/acre) of N with sulphur as a 1st application for grazing.

There is scope to apply slurry rather than fertiliser N on paddocks with the lowest grass covers. Avoid slurry on heavier covers until after 1st grazing. Remember that ammonia (N) losses from slurry double for every 5OC rise in air temperature. This is why spring applications are encouraged, to reduce ammonia emissions and increase N use efficiency.

Prioritise slurry for paddocks with a potassium index of 0 or 1 (especially ones which had bales removed last year) and silage fields. Reduce the fertiliser N application rates on paddocks that have received slurry. Allow for 6 units/N per 1,000 gallons with splash plate and 9 units/N with trailing shoe. Don’t apply slurry and N fertiliser at the same time, it’s best to leave at least a week between them.

Target paddocks with a phosphorus (P) index of 0 or 1, with a YaraMila compound, such as Stock Booster S (25-5-5+5%S+Se). These colder and wetter spring conditions reduce P availability and can lower grass growth.

Read more information on grassland nutrition

Nutrient watch – spring grassland

07 February 2020

The monthly rainfall data from the Met Office from September to January confirms what we already know: its’ been a very wet autumn and winter. The rainfall for England is 35% above average for the period. However, soil temperatures are running slightly above average which is a help. But what’s the upshot of all this rain? Nitrogen and sulphur are the obvious nutrients that will be affected, but soil phosphorus availability should be considered also.

For a grass sward, 70 - 80% of all root mass down to a depth of 23cm is in the top 7.5cm. Below 23cm root mass drops considerably. In reasonable winters you’d expect that some nitrate and sulphate would remain in this surface root zone, but with over a third more rain having fallen during autumn and winter it’s reasonable to expect that very little nitrate and sulphate remains. This observation in the case of sulphur is supported from data on soil samples received in Yara’s laboratory in Pocklington during December and January.

In saturated fields phosphorus availability will be reduced. These conditions increase the solubility of soil iron and aluminium which in turn affect the availability of soil phosphorus. It’ll be important to get some NPKS fertiliser like YaraMila Stock Booster S (25-5-5+5%S+Se) onto grass fields as soon as conditions allow, to kick-start and maintain grass growth this spring. Remember that with the prevailing soil conditions nitrogen on its own won’t be enough. In drier years a 23% growth response is usual with early sulphur and phosphorus, so be sure to use a compound NPKS fertiliser to get your grass off to the best possible start.

Read about making your fertiliser work harder

Phosphate applications this spring

25 January 2020

Phosphate (P) is a key nutrient for grass. Its role in energy supply, root growth and tillering makes its availability crucial for grass growth in the spring. Although the plant’s requirement for P is small compared to that of nitrogen, its availability is essential.
On grazing farms, a portion of your total annual P requirement should be applied in early spring and have the lion’s share of it applied by the end of April. A fresh P application boosts availability, first in early spring when its natural availability is reduced in wet cold soils, and then in April and May when there is a very high demand for P from peak grass growth.

Typically, the phosphate in fertiliser is 100% water soluble; this however creates its own problems. As soon as you apply water soluble phosphorus to a soil, it becomes slowly fixed by iron and aluminium. The phosphate contained in YaraMila Stock Booster (25-5-5+5% SO3) is a mix of water soluble phosphate and Di-Calcium Phosphate (DCP). This DCP is not fixed by the soil but becomes available when triggered by the weak acids from grass root exudates. This ideal combination of two phosphate fractions, rather than one, results in superior availability of P for grass.

The maintenance requirement for phosphate (P2O5) on grazed swards is 20 kg/ha, however if your grazing platform is growing 15 t of dry matter with 80% utilisation, then your maintenance will be closer to 30 kg/ha.

Read about making your fertiliser work harder

Improving nitrogen use efficiency on livestock farms

10 January 2020

Agricultural nitrogen (N) management remains a key environmental challenge and has implications for water quality, greenhouse gas and ammonia gas emissions. More efficient use of N, has a significant effect on a farmer’s bottom line. Where N is not being recovered by the grass or by the cows and turned into saleable products (milk and meat) this is a financial loss to the farming system. Increasing N efficiency by improving utilisation of N by grass will result in lower losses of N to the air and water. If a farmer can get more production (grass, milk or meat) for the same quantity of N input, or get similar production using less N input, it will lead to higher levels of nutrient efficiency. It could also potentially offset the need for expensive additional feeds or to help increase the total milk or liveweight gain from each hectare.

N fertiliser planning should not just consider the seasonal grass feed demands of the herd, but also the potential of the different soils/fields and swards to utilise applied N inputs over the season for grass production. Improvements in nitrogen use efficiency (NUE) and pasture productivity can be achieved by putting together a nutrient management plan for the year, utilizing manure N sources efficiently, including low emission slurry spreading application methods, using the right N fertiliser type at the right-rate and the right time, improving grazing management, reseeding poorly preforming swards and optimising soil fertility, especially soil pH

Read more about making your fertiliser work harder

Healthy soils for quality grass

29 November 2019

With over 40% of UK grassland soils deficient in phosphate and potash, and 25% reading below 5.5 for pH, there is potential to make simple corrections to improve grass yield and quality. Awareness of the benefits of improved soil health is driving more farmers to soil test regularly and with a more holistic approach beyond testing for just P, K, Mg and pH. The basics of a soil test are still vitally important, potentially revealing pH and macro nutrient imbalances. When these are addressed they can improve dry matter yields by 50% in some cases.

Without a soil test, applications of nutrients to soils pose not only a risk of environmental pollution, but an unnecessary cost to the farmer. Phosphorous applications to soils at pH 6.0 reduce its availability by almost half. The same effect will occur to nitrogen and potassium applied to soils at pH 5.0. High levels of rainfall this autumn have depleted nutrient reserves and accelerated soil acidification, another reason why a soil test might be timely.

If you are soil sampling, remember that a soil test is required for each field and tests should be no older than 5 years old for the purpose of nutrient management plans. It is worth considering testing soil trace elements, plus cobalt, iodine and selenium, within Yara’s Animal Health Soil test to help identify if the full dietary requirements of livestock are being met from grass.

Read more about soil analysis

It’s time to start thinking soil sampling

01 November 2019

Since April 2019 soil sampling has changed from something we should do, to something that we must do. DEFRA introduced the new rules to help protect water quality in England. They make it necessary to soil test, and then use the soil test to plan and apply fertiliser or manure to improve soil nutrient levels and meet crop needs. These soil test results must not be more than 5 years old.

The rule change is no surprise as regular soil analysis is the key to nutrient management on a farm. Tests provide a reliable guide to assessing soil fertility and provide the basis for sound applications of lime, organic manures and mineral fertiliser. Much of what a soil test allows us to do is to distribute valuable manures within your farm to make the best use of purchased fertiliser.

If you are an intensively stocked grassland farmer, it may be worthwhile to soil test annually. Fertiliser recommendations are not an exact science, hence soil testing more frequently together with measuring grass yields will help you fine tune your nutrient management plan (NMP) for every paddock.

Wait at least 3 months to soil sample after an application of organic manure or mineral P & K. Sample to a depth of between 7 and 10 cm’s on permanent grass leys. A soil test taken every 3 years will cost £1 per ha/year. However, it’s only value for money if you use your soil analysis results to implement a farm NMP

Read more about soil analysis

 

Interesting findings from Grass YEN 2019

22 November 2019

Grass YEN, the industry-science platform had its end of year meeting back in October. Yara were once again co-sponsors of the event, and I would like to take this opportunity to thank the five farmers that we sponsored for their time and energy in participating in this year’s competition.

At the core of Grass YEN is the accurate measurement of grass yields. It’s a cause for concern and an impediment to progress that so little is known about grass silage yields on UK farms. Most of the farmers who participated in this year’s YEN weighed the grass in a 3 metre length of swath at 5 random locations after mowing.

It would be preferable to weigh all grass over a weigh bridge, but not many farms have this luxury. ADAS & John Deere this year carried out a trial to test the relative accuracy of a number of different methods. They compared these methods to a whole field yield weight from trailers run over a weigh bridge. The swath method was shown to be accurate when it was compared to a whole field weight using trailers and a weigh bridge.

It’s important that we continue to build on the data that has been gathered from the last two years of Grass YEN, as this collaborative approach between farmers, industry and research is capable of delivering a cost effective improvement in grass silage management.

If you would like to participate in Grass YEN for 2020, please get in touch with us via email, facebook or twitter

Read more about grassland nutrition

 

Managing winter grazing

14 November 2019

Good management of grazing from autumn through into early spring can increase the quality of first cut silage.

Managing winter grass residuals can increase first cut D-value 

If producing high D-value silage is the objective on farm, then good grazing management this winter and spring has an important role to play. Good grazing conditions have allowed fields to be grazed to the desired residual, without causing too much damage to the sward.
Grazing down to a residual of 5cm from late autumn into early spring – is the key to ensuring that re-growth is of a high D-value. Longer residuals can lead to dead vegetation accumulating and therefore the quality of the sward will be reduced significantly.

Although weather conditions are favourable at the moment, if soil conditions deteriorate and livestock begin poaching then they should be removed or this will also affect 1st cut yields and quality. Weather conditions can make grazing difficult and the desirable height a challenging target to hit during early spring. It might be an option to graze fields now that are intended for 1st cut silage.

Research has shown that fields un-grazed from late autumn into early spring will produce lower D-value silage compared to those that were grazed. Un-grazed fields during this period that are harvested for silage in late May will have an estimated D-value that is on average 7% lower than if they were grazed.

However, there was no difference in silage D-value if grass was grazed in late autumn/winter versus early spring and harvested in late May. The quality of silage also depends on harvest date, growth stage at harvest and fertilisation.

Read more about grassland nutrition

Silage mineral analysis - what does it all mean?

14 October 2019

Silage mineral testing is usually carried out to calculate livestock mineral supplementation rates. However, tests can also help review how well your silage crop was fertilised. A simple interpretation of your mineral analysis may shine a light on a particular problem, such as poor yields or low silage protein. The results quoted on these mineral analysis will be in elemental form and on a dry matter basis.

Nitrogen (N) – Disappointing grass yields combined with a low N % (and protein %) on the report, even though the grass was cut with high to medium proportion of leaf to stem, could be symptomatic of sub-optimal N applications. This is not surprising since N is required to facilitate growth through chlorophyll production and build plant proteins.

Sulphur (S) – Your silage should have an S % of more than 0.25 %, and an N:S ratio of between 10:1 and 13:1. The N:S ratio is calculated by dividing the N % by the S%. S is associated with plant N uptake and is a building block of plant proteins. Any deficiency is usually not noticeable in the grass before harvest but low yields and lower proteins levels are associated with low sulphur. The essential amino acids cysteine and methionine are usually low in S deficient grass.

Potassium (K) – Low K % (< 2 %) in silage might indicate that the crop didn’t receive enough K. Low grass yields and poor responses to N can often be associated with poor K crop nutrition. Soil test if you haven’t done so and apply K as per recommendations (RB 209).

Phosphorus (P) – Low P % (< 0.25 %) could indicate that the crop did not receive adequate soil phosphorus supply. This can be prevalent in 1st cut silages, as rapid growth in combination with cold and/or wet soils can reduce the availability of soil phosphorus during this period of growth. Soil test and apply P as per recommendations (RB 209). There is evidence from AFBI in Northern Ireland, that highly productive swards can experience a P deficiency if grown at the lower range of soil P index 2. Hence, keeping these soils at the upper range (21-25 mg/l) of index 2 for P may be preferable.

Selenium (Se) – If you haven’t used a Se fortified fertiliser, then it’s most likely that your silage will be very low in Se. Typical Se levels in silage are less than 0.07 ppm (<0.7 mg/kg). At these levels, there is not enough Se in this silage to meet the demands of cattle and sheep. By using a Se fortified fertiliser next season, you can simply remedy the problem.

Regular testing and analysis are essential to get the best from your silage crop

Read more about grassland nutrition

More effective weed control on autumn reseeds

26 September 2019

When getting the sprayer out to control grassland weeds on autumn reseeds, there is an opportunity to add a foliar fertiliser for two reasons.

  1. The effectiveness of herbicides on autumn reseeds can be improved if a foliar fertiliser is tank mixed with the herbicide. The foliar fertiliser works by stimulating the weeds to grow more actively, which results in more of the active ingredient being taken up by the weeds.
  2. Spraying reseeds with herbicide can knock the young grass plant back, especially in late autumn when growing conditions are not ideal. The use of a foliar fertiliser with the herbicide helps the grass plant cope better with the stress of being sprayed. Grass which is supplied with a full complement of nutrients at the onset of an environmental stress is more resilient. The improved growth of grass seedlings will help fill in bear patches, reducing light and space for any new germinating weeds.

We recommend YaraVita Croplift Pro at a rate of 2.5 kg/ha or 1 kg/acre in conjunction with your grass herbicide. It contains a full complement of nutrients to ensure the long-term success of your new ley. YaraVita Croplift Pro can be safely tank mixed with almost all common grassland herbicides, if in doubt ask your supplier about compatibility.

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Nitrogen: to spread or not to spread?

13 September 2019

Spreading nitrogen (N) from now on should be considered carefully.

The growth response will have to justify the cost.  As we approach winter, excess or unused soil nitrate is something we want to minimise as it constitutes a risk to water quality. NVZ rules on grassland allow for up to 80 kg/ha of mineral nitrogen to be applied between the 15th of September and the 31st of October, with 40 kg/ha of N the maximum allowed in any one application.

Preferably N applications should take place earlier, at a time when grass growth is sufficient to utilise it. Teagasc research on autumn applied N has shown that 30 kg/ha of N applied on 1st August, 1st September and 1st October gave a grass dry matter (DM) response of 27 kg’s, 19 kg’s and 10 kg’s respectively for each kg of N applied. If we assume that this grass DM contains 3% N, then our apparent N recovery rate was 80% for August, dropping to 30% for October.

It’s important that any N applications take into account the requirement for grass, sward quality and soil and weather conditions as grass grown needs to be utilised. A paddock by paddock choice should be made on the rate of N. Drier paddocks receiving more, heavier soil types receiving less. N application rates in my opinion should not exceed 30 kg/ha and be applied no later than mid-October.

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Fertilising short term leys and brassicas

24 August 2019

Fertilising these crops adequately is necessary to obtain the maximum yields they are capable of producing. In general these crops are being sown after a cereal crop, therefore the soil nitrogen supply is likely to be low.
For temporary leys following cereals, we recommend up to 50 kg/ha of nitrogen, phosphate and potash for establishment. The phosphate in particular is important for root development and tillering. YaraMila Actyva S (16-15-15 + 6.5% SO3) will provide a consistent and reliable supply of phosphate for the remainder of the growing period.

Remember that for every 1cm of grass growth the N requirement is 7.5 kg/ha. We would expect Italian ryegrass or Westerwolds to grow to a minimum height of 10 cm by the end of October, therefore requiring 75 kg of N. If we apply 50 kg of N from the bag, there will be enough soil residual N to provide the remaining.

The hybrid brassicas such as Redstart and Interval may still be drilled into late August and they have similar nutrient requirements to that of forage rape and stubble turnips. We recommend up to 80 kg of nitrogen, 25 kg of phosphate, 50 kg of potassium and 30 kg of sulphur per hectare. A perfect fit for these nutrient requirements is YaraMila Silage Booster (20-4.5-14.5 + 7.5% SO3 + Se).

It’s important to get these crops off to a good start, so placing the fertiliser in the seedbed will help to establish strong healthy plants.

Read more about grassland nutrition

 

Grow grass now to extend your autumn grazing

02 August 2019

From mid-September daily grass growth will fall rapidly. After this point grass can quickly run out and either livestock performance declines or they will require housing to maintain performance. If we start to manage grass now, we can grow more grass over the coming weeks. This then allows us to build up a bank of grass for extending the grazing period and, if correctly managed, allows for earlier turnout of livestock in the spring.

Grass grown now will remain leafy, albeit not as good as leafy grass grown earlier in the year.  It will not require the same level of purchased feed to maintain a certain level of milk yield, or daily liveweight gain, compared to feeding poorer quality forage indoors or set stocked grazing where there is poorer quality grass with lots of dead material at the base.

If we optimise grass growth over the coming weeks by applying nitrogen and sulphur now and operating a rotational grazing system (even if it’s temporary fencing) then we can save money and shorten the indoor period. This means that livestock will need to graze an area and then be moved onto a fresh area every 1-4 days, allowing the sward to recover and start growing again. The drier or ‘earlier’ parts of the farm should be grazed from mid-September and then closed off as the regrowth on these parts can be carried over the winter months for grazing first in the spring.

Read more about grassland nutrition

 

Successful reseeding this autumn

22 July 2019

A new perennial ryegrass (PRG) sward can often be the most challenging crop to establish on a grassland farm. The main benefits of a new PRG sward are improved dry matter (DM) yield, and improved nutrient use efficiency.

Step 1 : identify poorly performing paddocks.

Step 2 : assess their perennial ryegrass content. If this is less than 60% consider re-seeding as annual meadow grass and other weed grasses produce lower yields, poorer feed quality and do not respond well to applied nutrients.

Take a soil test beforehand so that action can be taken to correct soil pH. On mineral soils the optimum pH for grass is 6.3, failing to correct pH will severely impact the success of your reseed. Choose only varieties from the recommended list and pick those that suit your particular farm and system, with a small range in heading dates. Failure to provide new PGR swards with the correct nutrients at sowing will hinder the success of the ley. Using a quality NPKS compound fertilizer such as YaraMila ACTYVA S (16-15-15 + 6.5% SO3), will support the new plant, especially its phosphorus and nitrogen requirements which are critical for establishment.

Applying herbicide to control weeds 4 to 6 weeks post-emergence will prevent weeds from competing for nutrients and space. This combined with a light grazing when grass height is at 8 – 10 cm will promote new shoots and thus the long term productivity of your new sward.

Read more about grassland nutrition

How to maintain quality grazed grass this June

30 May 2019

Grazed grass quality has a direct impact on profitability, and those farmers who are actively managing their grassland will understand how maintaining grass quality during the month of June pays dividends.
Grazing management in June is a fine balance between grass quantity and quality, and cow performance. Trying to graze down to 4cm after poor residuals in the previous rotation is a real problem. We also have to contend with grasses heading out, which can often be compounded by nutrient stress.

Some farmers are using pre-mowing as a means to manage this period and maintain grass quality. Pre-mowing can help grazing management but should not be seen as a replacement. It is most commonly used to put paddocks ‘back on track’ where high residuals are carried over from the previous rotation. It’s difficult in this scenario to have cows graze around dung and urine patches, therefore pre-mowing is beneficial.
It is important to remember that pre-mowing when grass supply is tight or very dry, will lead to a faster rotation and consequently drop the average farm cover and increase the feed deficit.

Grass covers that are 200-300kg DM/ha higher than the optimum can be mowed to counteract losses and increase cow intakes. Mow no more than 2.5pc of the farm on any one day, so that it will require at least two grazing rotations to mow the whole farm. Finally, it's essential to mow tight to achieve the desired post-grazing residual of 4 cm’s.

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Don’t be complacent – build forage reserves while you still can

05 July 2019

With reports of good crops of 1st and 2nd cuts being taken, it seems like it’s been a good grass year. Compared to last year, it’s a great year but if you look at the GrassCheck GB average growth figure for the year-to-date we’re marginally below the long-term average at 6.02 t DM/ha.

On intensive grazing farms, pushing grass growth is still key and maintaining residuals of 4 cm. Heavy covers of > 3,000 kg should be cut as surplus bales and maintain grass growth by keeping N + S applications up-to-date whilst growing conditions are still favourable. Slurry should be applied (by low emission spreading equipment to reduce ammonia emissions) where silage/surplus bales are taken off. If slurry is not available, then apply a NPKS or NKS quality compound fertiliser such as YaraMila SILAGE BOOSTER or YaraMila NK SULPHUR to replace P and high K off-take from taking surplus bales.

It’s prudent to check silage stocks now and unless you’ve a comfortable surplus for the winter, consider adding to these stocks with 3rd cuts. If the silage area is going back to grazing, fresh N + S applications will speed up aftermath growth. Growing a surplus of grass now on silage aftermaths, is sensible as it might save silage being introduced to buffer grazed grass in August if it turns dry.

Take advantage of the favourable weather conditions to build forage stocks, because knowing how unpredictable our weather is now; you could have to feed it in August!

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P & K advice for summer grassland

07 June 2019

Grass growth has been good, with yields ahead of target in most areas. Where 1st cuts were taken early, 2nd cuts will be about to be in the clamp, if not there already. 1st cuts were very heavy, but recovered quickly and are taking advantage of the current good growing conditions. Whether it’s for grazing or silage, it’s beneficial at this point to reconcile grass offtake with nutrient inputs. This will optimise grass growth over the coming months and prevent soil fertility from slipping further where P & K indices are 2- or lower.

If you know good indices and a good soil pH exist for your fields or paddocks then you have some leeway. However with good yields comes higher offtakes so there are no free lunches to be had when it comes to soil fertility. 

Maintenance dressings of P & K are most easily applied as an NPKS compound. This ensures the nutrients are evenly applied. Compounds such as YaraMila EXTRAGRASS (27-5-5 + 6% SO3) or YaraMila STOCK BOOSTER S (25-5-5 + 5% SO3 + Selenium) have 10 times more phosphate landing sites than a similar blended product. Three dressings of either of the products above at 130 kg/ha per application is sufficient to deliver the maintenance requirements of phosphate for grazing.

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Tackling low selenium and phosphorus in grass this breeding season

24 May 2019

Selenium (Se) and phosphorus (P) both play a fundamental role in cow reproductive health. Yara Analytical Services data shows that 99% of grass samples received in 2018 were Se deficient and 39% were P deficient. A dietary deficiency in Se is associated with cystic ovaries, anoestrus and early embryo death. While P deficiency results in irregular oestrus, silent heats and low conception rates. Cows not going back in calf is the single most common reason for culling in dairy herds according to the 2018 Kingshay dairy report.

A lactating cow requires daily P and Se intakes of 4 g and 0.3 mg respectively for every kg of dry matter (DM) intake. We can increase the P content in grass and maintain the levels in the soil by applying fresh P in small, but frequent, applications from spring onwards. These fresh applications will raise grass P levels to 4 g/kg DM and will contribute to the 20 kg/ha annually needed to replace grazing offtakes.

Increasing grass Se levels to the desired 0.3 mg/kg DM is simply and safely possible by applying a quality selenium-fortified fertilizer like YaraMila YaraMila STOCK BOOSTER S (25-5-5 + 5 % SO3 + Se) from early spring onwards. Because this product is a true uniform compound, each granule contains P and Se, which guarantees every bite of grass contains an adequate supply of these nutrients for your cows. By fortifying grass we’re not relying on other forms of Se supplementation, this gives us the flexibility to cut back on concentrate feed without jeopardising Se intakes.

Read more about Yara's Booster fertilisers >

Heavy first cut silage removing K which needs replenishing

16 May 2019

Heavy crops of 1st cut are being taken currently, especially from fields which were not grazed in the spring. Four of Yara’s six Grass YEN participating farmers have taken their 1st cuts at this stage and by all reports, yields are very good. 

Early May cut 1st cuts have greened up nicely and N applications for 2nd cut silage will depend on an estimated cutting date. Allow 2.5 kg/day (2 units/day) as a rule of thumb for N requirement, and account for available N in slurry. The book value for N in 6% DM cattle slurry is 2.6 kg/m3, with 20 – 30 % of this available for your 2nd cut. To convert kg/m3 into units per 1,000 gallons multiply by 9.

Heavy 1st cuts at this time of May, could easily be removing 5 tonnes/ha or more of DM, this equates to 165 kg/ha of K2O so 2nd cut fertiliser applications of YaraMila Silage Booster or YaraMila Sulphur Cut will deliver extra K which will replenish soil K if slurry is limited. 2nd cuts are not effected by luxury K uptake to the same degree as 1st cuts. 

Grass P levels normally drop at this time of the year, which coincides with a period in the year where farmers are breeding cows and P is a key nutrient in cow fertility. Dairy cows need ~ 4 grams of P (elemental) per kg of intake. Small frequent applications of YaraMila Extragrass or YaraMila Stockbooster S will combat this and go a long way to maintaining soil P levels. RB209 recommends 20 kg/ha of P for maintenance. Herds pushing on greater than 10 tonnes of grazed grass being utilised and not feeding high levels of concentrates will require more than this to maintain soil P levels.

Read more about grassland nutrition

Growing maize? Then don't forget it's nutrient requirements

03 May 2019

Just because your maize crop is now planted don’t forget about its nutritional needs. Maize has a high demand for nutrients, because of its high yields. These high yields of 40+ tonnes/ha can only be achieved if the crop can access enough nutrients via its roots and, as the plant grows, through foliar applications.

Zinc and magnesium deficiencies are the two most widespread nutritional disorders in maize. Zinc is important for photosynthetic activity. Magnesium deficiency affects the early establishment of the plant which is reflected in reduced crop yield at harvest. Phosphorus and potash are major nutrients, however many soils have not got the capacity to deliver an adequate supply. Commonly, phosphate availability is reduced because of soil pH.

One or more of these nutrients is often deficient in the growing maize plant and this is particularly important as the plant reaches the 4 to 5 leaf stage. It’s at this stage that yield is being set. Maize stressed at this point can result in tall, thin plants, with poor root systems and reduced leaf area. This reduced leaf area captures less light, resulting in lower yields.

We can overcome this risk of a reduced yield through nutrient deficiency by applying foliar nutrients, at leaf stage 4 to 5. On dry soils where phosphate uptake might be impaired, foliar phosphate is translocated from the leaf, to the roots very effectively, maintaining root development.

YaraVita Maize Boost is specifically formulated for foliar applications on maize, to deliver a high concentration of phosphate, zinc, magnesium and potash to maximise yield and quality this harvest.

Read more information on forage maize nutrition

Is zero-grazing an option?

26 April 2019

Zero-grazing is being employed on many dairy farms across the UK as an alternative or supplementary practice to grazing and silage based milk production systems. Increasing herd sizes and the need to reduce feed costs by producing more milk from forage is driving farmers to new ways of utilising grass. It offers farmers greater flexibility, especially those with limited grazing capacity around the milking parlour. It is more labour intensive, but it is an option worth considering.

Research at AFBI in Northern Ireland points to improved cow performance from zero-grazed grass compared to grazed or silage fed systems. These zero-grazed fed cows also maintained heavier live weights over the course of the study. What determines the success of any of these systems is grass/silage utilisation per hectare. Margin over feed costs per hectare was greatest (£3,580) for the zero-grazed cow group, while the silage fed group came out slightly below this, and the grazing group was even lower. The reason for this was the higher stocking rates of the indoor groups which more than compensated for the lower per cow feed costs attributed to the grazing group.

The performance above was achieved by zero-grazing quality grass. Harvesting covers of not greater than 3,500kg DM/ha is preferable to reach these performance levels in zero-grazed herds. Harvesting grass at pre-harvest covers of 4,500kg DM/ha rather than 3,500kg DM/ha led to a decrease in cow performance and grass growth, estimated at £0.57 cow/day. Zero-grazing is a viable alternative but only with excellent grassland management.

Read more about grassland nutrition

Growing better grass through timely N applications

12 April 2019

In a recent AHDB dairy publication, the practice of blanket spreading the entire grazing platform at the one time with Nitrogen was discussed. It’s a labour saving practice, which suits contractors mostly, but can also free up time for the farmer. It’s not practical to spread nitrogen every day or second day, but there are consequences to only spreading once every month or every three weeks.

A sward will recover quicker after grazing or cutting when fresh nitrogen has been applied. The bulk of this freshly applied nitrogen is then taken up by the plant, over the following 21 days. Nitrate concentration in the grass peaks in the first two weeks as the plant needs this nitrate for photosynthesis and protein synthesis. Nitrate levels then begin to drop gradually in week 3 as growth surges. This is due to greater light interception by the expanding leaf canopy which dilutes the nitrate levels within the plant. It’s for the same reasons that we don’t apply nitrogen for our 2nd cut silage the week before the 1st cut is harvested.

Cows that graze paddocks which have just received nitrogen applications in the previous week, will be using up more valuable energy on removing this nitrate from the grass as urine. This is counter-productive as energy is the limiting nutrient on predominantly grass based diets. By increasing urine nitrogen, we’re increasing nitrogen losses to the atmosphere as ammonia. We have to strike a balance, and spreading nitrogen once a week on the paddocks grazed in the previous 7 days works well.

Read more about grassland nutrition

Quality compound fertiliser – it pays every time

29 March 2019

At this stage, most 1st cut fertiliser applications are complete, but are you confident that your target fertiliser rate was evenly applied?

Yara has demonstrated over a 24 metre bout width how the physical quality of a fertiliser influences the yield and quality of a grass crop.

Yara compared YaraMila Extragrass (27-5-5+S) with a blended 27-5-5+S. The target rate for both products was 500kg/ha and the spreader settings were changed for each product on testing. The YaraMila product achieved the target rate across the entire bout width; however the application rate for the blended product varied hugely, from 400 to 648kg/ha.

Each of the 23 trays from the blended product were analysed individually to determine their actual NPK+S content. Because the YaraMila product is a compound, we know that the product in each tray contained 27% N, 5% P and 5% K. The target per nutrient was 135kg, 25kg and 25kg for N, P and K respectively. The blended product had a variation in N across the bout width of between 91kg and 160kg, for P the variation was 10 to 19kg and for K it was 34 to 59kg/ha.

Due to the poor spreading pattern of N in this blend, and when compared to the accuracy of YaraMila Extragrass, there was a yield loss of nearly 400kg/ha of grass dry matter. This equates to 1.5 tonnes/ha of silage which would have a current replacement value based on barley and rapeseed meal of £60.

This shows the importance of a quality compound fertiliser where you can be confident of an accurate nutrient application across the entire field.

Read more about YaraMila NPK fertilisers >

How we put a value on sulphur for 1st cuts

15 March 2019

Calculating the return from using sulphur to grow forage crops is not straightforward, and it’s important that the way we calculate it is transparent, fair and easily understood.

Yara calculates the value of forages, such as grazed grass or silage on their replacement cost, relative to purchased rapeseed meal and barley. Many other companies value forage based on the value of the extra milk or meat produced. This assumes that a litre of milk requires 5.4 MJ ME and a kilo of liveweight gain requires 45-50 MJ ME. We feel this approach does not give the farmer a fair appraisal.

If we apply sulphur on 1st cuts this year using a product such as YaraBela AXAN (27% N + 9% SO3), we are likely to increase dry matter (DM) yields by 20% per ha or 1 tonne of DM. The cost of the sulphur is £15/ha. We assume an utilisation of 80%, the silage is 25% DM and has an ME of 11 MJ/kgDM and protein is 14%. Rapeseed meal is costing £198/tonne and barley £132/tonne. Using the above figures, we can calculate how much this 0.8 tonne (80% of 1 tonne) of extra 1st cut is worth, relative to Rapeseed meal as the protein source and Barley as the energy source.

The value of this extra 0.8 tonne of grass silage is £111. The cost to grow it is £15. This equates to a return of £7.50 for every £1 spent on sulphur using YaraBela AXAN on 1st cuts this spring.

Read more about YaraBela nitrate fertilisers >

Fertiliser quality - an important consideration this spring

04 March 2019

Over the last two weeks I’ve been asked by a number of farmers what effect has fertiliser quality on grass yields and quality. Essentially what we are concerned with is the uneven application of nutrients across the spreader bout width and its effect on yield and quality. The coefficient of variation (CV%) is a term used to describe this unevenness, a CV of <10% is considered very good and a CV of >20% is a problem. Work in New Zealand on phosphate applications found that grass yield losses trebled, as the CV increased from 20 to 30%.

We must distinguish between the uneven application of the product and the uneven application of individual nutrients. With true uniform compounds, like YaraMila the granules or prills are uniform and each contains the same analysis as the product. With blended fertilisers, there can be up to 4 individual components making up the NPKS. Therefore, you have 4 different materials with each possibly having a different spreading pattern. When carrying out a tray test on a blended fertiliser you also need to focus on the evenness of spread of each individual component.

Pay particular attention to the evenness of spread of the phosphate component in a blend. If we take a blended 25-5-5 product being applied at 225kg/ha and compare this to a quality compound, there are 50 phosphate landing sites per m2 with the blend and 500 with the compound. The aim is that each of the 400-500 grass plants/m2 in a sward has access to fresh phosphate in spring to optimise growth.

Read more about YaraMila NPK fertilisers >

The nutritional role of potassium in grass production

24 February 2019

High yielding grass crops have a high requirement for potassium (K). The majority is required for the essential role of maintaining water balance within plant cells. Since grass is made up of 80% water, the availability of soil potassium is key to optimal grass growth.

Within the grass plant potassium is found in similar levels to nitrogen and it helps improve both the uptake of nitrogen from the soil, and the conversion of nitrogen to protein within the plant. During peak grass growth in early May, daily K2O uptake can be as high as 4-5kg/ha.

The K in grazed grass is efficiently recycled by livestock, however silage crops remove 10 times more K from a sward than grazing. This means for every 1 tonne of grass dry mater eaten or harvested, grazing removes 3.6 kg and silage 36 kg. A 1st cut yielding 5 t/DM/ha will remove 180 kg of K, and it is because of these large removal rates that soil K indices must be carefully monitored as they can decline quickly over 2 or 3 years.

Mineral K will be required each year if organic manures are not being imported onto the farm as K is not recycled with 100% efficiency. Milk and livestock remove K and in addition a small portion will be leached from the soil. Slurry/FYM should be targeted to areas where silage has been taken from and application rates should be proportionate to silage yields.

Read more about YaraMila NPK fertilisers >

Boost selenium levels in your spring grass

15 February 2019

This spring we should not overlook the potential of fortifying grass for grazing or for silage with selenium (Se). Data from Yara analytical services shows more than 90% of grass and grass silage samples tested are deficient in selenium. Increasing the Se levels in the grass can significantly reduce health problems in your livestock. Using a fortified fertiliser ensures that grass or silage has Se levels that meet the animal’s requirements of 0.2-0.3 mg/kg DM.

We might believe that using fertiliser fortified with Se, such as YaraMila STOCK BOOSTER S (25-5-5 + 5 % SO3 + Se), is only useful for grazing livestock but this is not the case. If grass silage is fertilized using our YaraMila SILAGE BOOSTER (20-4.5-14.5 + 7.5% SO3 + Se), this silage will have enough Se to meet the needs of ewes and cows. Livestock utilise the Se in grass and silage more efficiently than the Se found in boluses, licks and TMR mineral mixes.

Whether it’s a lactating ewe or cow, there is an increased demand for Se because of milk production. It’s therefore important to maintain Se intakes in this spring period when lactating livestock go out to grass to avoid high cell counts, increased rates of mastitis and poor reproductive performance. Yara uses sodium selenate to fortify their Booster range of fertilisers. Sodium selenate is used as it’s taken up by the grass more efficiently, upon application. Unlike blended fertilisers, the Booster range of fertilisers contains Se in every granule, ensuring the same levels of Se in every bite.  

Read more about Yara's Booster fertilisers >

Take control of early spring sulphur

07 February 2019

Sulphur deficiency is now widespread across Northern Ireland. AFBI research has shown that dry matter yield losses of 30% are now occurring at 1st cut or 1st grazing as a result of sulphur  deficiency. Lower protein levels in grass and silage are another consequence of sulphur  deficiency, as sulphur plays an integral part in protein synthesis. The protein content of grass declines, and this not only reduces its value as a protein source for ruminants, it also hampers its ability to accumulate sugars and thus impairs its fermentation quality when ensiled. A shortage of sulphur in herbage (<0.2% S in DM) can also reduce the digestibility of forages. Rumen microbes require both nitrogen and sulphur to produce their own protein, and a shortage of S will therefore curtail important metabolic functions.

Sulphur  deficiency can occur in spring on all soil types, regardless of whether or not slurry has been applied. The availability of slurry-S for spring grass is highly variable and often low, largely because variable amounts of sulphate (the plant available form) are converted into sulphide (a potential plant toxin) under anaerobic slurry storage conditions.

We should manage sulphur  applications the same as N applications. If we apply all our sulphur in one application then we risk losing it to leaching. S leaching is wasteful but also very acidifying to soils. The ‘little and often’ approach to S applications does not have negative effects that ‘once off’ applications have. Similar to efficient nitrogen management, we apply the right amount of S as and when the plant requires it.

YaraVera Amidas is a urea based nitrogen (N) and sulphur (S) granular compound fertiliser from Yara, with 40% N and 14% SO3. Because it contains urea it’s well suited to spring use, delivering a stable and sustained supply of nitrogen in the weeks following application. 100% of the sulphur in Amidas is in the plant available form, unlike the S in organic manures. Therefore, you can rely on Amidas to provide a constant supply of sulphur over this critical spring period.

YaraVera Amidas has lower ammonia emissions than straight urea. The sulphur has an inhibitory effect on ammonia production during the conversion of urea to ammonium-N which is due to the Amidas granule containing both urea and S. This effect is not seen with blended urea and ammonium sulphate (AS) products. Because there is less ammonia lost, there is more N available for the crop to support grass growth, the S component has the double effect of reducing N losses while meeting the grass crops requirement for S to support higher grass yields.

Read more about YaraVera urea based fertilisers >

Your phosphate applications this spring

18 January 2019

Phosphate (P) is a key nutrient for grass, and its role in energy supply, root growth and tillering makes its availability crucial for grass growth in the spring. The plants requirement for P is small when compared to nitrogen but its availability is essential.

On grazing farms, a portion of your total annual P requirement should be applied in early spring and have the lion’s share of it applied by April. A fresh P application boosts availability at a time when its natural availability is reduced by low soil temperatures in early spring and then by April and May, when grass growth is peaking, there is a very high demand for P.

Typically the phosphate in fertiliser is 100% water soluble; this however creates its own problems. As soon as you apply water soluble phosphorus to a soil, this soluble phosphorus becomes slowly fixed by iron and aluminium. The phosphate contained in YaraMila NPK’s such as YaraMila Actyva S (16:15:15 + 6.5% SO3), is a mix of water soluble phosphate and Di-Calcium Phosphate (DCP). This DCP is not fixed by the soil but becomes available as it is triggered by weak acids from grass root exudates. This ideal combination of two phosphate fractions rather than one results in superior availability of P during the spring.

The recommended (RB 209) maintenance requirement for phosphate (P2O5) on grazed swards is 20 kg/ha, however if your grazing platform is growing 15 t of dry matter with 80% utilisation, then your maintenance will be closer to 30 kg/ha.

Read more about YaraMila NPK fertilisers >

Early grass is more critical than ever this spring

04 January 2019

After a challenging year and depleted forage stocks, early grass growth has never been more important. So it is crucial to get the timing of your first fertiliser dressing correct. Research by Teagasc, Moorepark on early spring applications of nitrogen (N) demonstrated that there was a return of at least 10 kg DM per kg N applied and a first dressing applied late, can delay grass growth by up to 3 weeks.

Why is this early fertiliser critical? As day length and soil temperatures begin to increase in spring, the grass plant is at its lowest ebb in terms of energy. It needs nitrogen to trap sunlight and therefore grow, if we supply nitrate that’s easily taken up by the root system then photosynthesis and grass growth will begin earlier.

The other problem to address is sulphur lost over the winter period through leaching. We know sulphur availability is crucial for nitrogen to work effectively so by applying nitrogen and sulphur together we will see a boost in grass growth.

On intensively stocked grazing farms a first dressing of 160-120 kg/ha of YaraBela Nutri Booster (25% N, 5% SO3 and selenium) is the ideal choice because it contains nitrate nitrogen, sulphate (rather than elemental sulphur) and sodium selenate. The nitrate and sulphate can be immediately taken up by the roots, and this will kick start grass growth while the sodium selenate in every granule will provide selenium in every bite of grass for healthier livestock.

Read more about Yara's Booster range of fertilisers >

Minimise risk from 1st cut fertiliser applications

29 November 2018

This spring was unusually late, however should we be surprised with the way the weather has been! According to the Met office we are experiencing more of these extremes. Whether you believe that these changes are a result of humankind’s efforts or not, we will have to factor in these weather events on how we manage our farms.

A prime example of this would be this year’s trial results on 1st cut silage from the south-west of England. It is apparent how a simple fertiliser choice could mean entering the winter period with just enough forage or face buying some to meet a shortfall. Because of the late spring, depending on your soil type and location, 1st cut fertiliser applications were not applied until the end of April or early May.

The result of the trial highlighted how urea was the wrong choice this year. The slurry + urea plots yielded an average of 3.44 tonnes/ha of dry matter, whilst the slurry + YaraBela AXAN (27% N + 9% SO3) plots yielded an average of 5.76t. There must have been significant nitrogen loss in the few days after urea was applied.

We can demonstrate the differences between fertilisers in a trial, but on farm we don’t have the luxury of comparisons as usually the products are bought in advance with no thought on what the spring might bring. When purchasing fertiliser for your 1st cut, remember sulphur and ammonium nitrate will deliver heavier crops.

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Understanding grass yield potential with YEN

16 November 2018

On attending the end of year meeting for the inaugural Yield Enhancement Network (YEN) for grass, it became apparent that the potential of grass as a crop is well and truly underestimated. The aim of this network is to close the gap between current yields and potential yields for grass silage crops.

Each farmer received a detailed report on each field entered in the competition. This includes the potential yield and what percentage of the potential yield was achieved. The average for all 1st cut entries was 66% of the potential yield, with the highest achieving 110%, this translated into an impressive crop of over 20 tonnes of DM per ha from a grass clover ley which was harvested in the first week of June. The average DM yield for 1st cuts was 6.8 t/ha and for 2nd cuts 4.8 t/ha.

The potential yield model calculates a theoretical maximum based on the information provided by the farmer for the field entered and that crop capturing more than 90% of total light energy and 75% of the available water to a rooting depth of 1.5 m over the growing period. The model will require further refinement as the factors that underpin yield are better understood.

It is widely accepted that grass leys on many farms are underperforming, probably as a result of the lack of information on performance. Any effort, such as Grass YEN which endeavours to capture information on grass silage leys in the common interest of increasing forage productivity must be welcomed.

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Fertilising short term leys and brassicas

17 August 2018

The interest this autumn in short term leys and brassicas is phenomenal but hardly surprising as farmers do whatever they can to fill a forage shortfall caused by a late spring and an extended drought. It’s important for these crops to ‘hit the ground running’ to make best use of the growing days available to these crops.
Fertilising these crops adequately is necessary to obtain the yields they are capable of producing. In general these crops are being sown after a cereal crop and therefore the soil nitrogen supply is likely to be low.

With temporary leys following cereals we recommend up to 50 kg/ha of nitrogen, 50 kg/ha of phosphate (P2O5) and 50 kg/ha of potassium (K2O) applied at drilling. The phosphate in particular is important for root development and tillering. YaraMila Actyva S (16-15-15 + 6.5% SO3) contains ‘P-Extend’ which will provide a consistent and reliable supply of phosphate for the remainder of the growing period. Not forgetting that these fast growing grass leys have a requirement for sulphur which is often forgotten.

Remember that the N requirement for every 1cm of grass growth is 7.5 kg/ha. We would expect Italian ryegrass or Westerwolds to grow to a minimum height of 10 cm by the end of October which will require 75 kg of N. If we apply 50 kg of N from the bag, there will be enough soil residual N to provide the remaining.

The hybrid brassicas such as Redstart and Interval may still be drilled into late August and they have similar nutrient requirements to that of forage rape and stubble turnips. We recommend up to 80 kg/ha of nitrogen, 25 kg/ha of phosphate (P2O5), 50 kg/ha of potassium (K2O) and 30 kg/ha of sulphur (SO3). A perfect fit for these nutrient requirements is YaraMila Silage Booster (20-4.5-14.5 + 7.5% SO3 + Se) with ‘P-Extend’.

Preferably on these short term leys and brassicas, the fertiliser should be incorporated into the seedbed and not broadcast afterwards. If the option exists when drilling the brassicas to use a drill which will combine the fertiliser application also then this would be advantageous for the quick establishment of the seedling.

Read more about YaraMila compound NPKS fertilisers >