Nutrition has always been important for good establishment of oilseed rape. Despite the continued decline in oilseed rape in recent years, there is still a significant area sown around the UK so autumn nutrition still has an important part to play.
Seed treatment gets a crop off to a good start
When getting a crop established nutrition can help get it off to a good start. If we start with a seed treatment then there are a couple of nutrients that are particularly helpful to a newly germinated seed.
Phosphorus (P) is important for protein synthesis, root and shoot development and energy transfer within the plant, however its mobility within the soil is very poor. Having a seed treatment that contains P means that it is in the correct place, near the seed, so that the newly developing roots can access it quickly and efficiently to give it enough P to get it growing.
Manganese (Mn) is a major contributor to various biological systems including chlorophyll production and oxidation and reduction processes in plants (electron transport in photosynthesis). Mn has a metabolic role in nitrate-reducing enzyme activity and activation of enzymes which play roles in carbohydrate metabolism, thus photosynthesis efficiency decreases with manganese deficiency. Therefore having it within a seed treatment will ensure the seedling has sufficient supply to kick-start growth.
A trial looking at YaraVita Glytrel MnP, which contains both Mn and P, showed that plant numbers doubled and root weights were over 4.5 times more in the treated side of the field than the untreated. Therefore the plants with more roots are better able to access resources and therefore established far better than the plants without the seed treatment.
Starter fertiliser placed at drilling ensures nutrient availability
The next stage of nutrition that will help establish the crop is by placing an NPKS fertiliser at drilling. OSR is allowed 30kgN/ha in the autumn if you’re in an NVZ, however if you’re placing your fertiliser you can reduce this to 25kgN/ha due to it being more precise. As I mentioned earlier P, in particular, doesn’t travel very far in the soil (less than 1mm) therefore placing the fertiliser at drilling will ensure that the nutrients are close to the seed so that they can access them quickly upon germination. This also means that less fertiliser is wasted by being spread in between the rows; P that lands interrow will soon become ‘locked-up’ (either by iron, aluminium or calcium ions) and therefore become plant-unavailable. When looking for a starter fertiliser for OSR a good fit for a solid product would be YaraMila Actyva S (16-15-15+6.5% SO3) or if using liquids then CHAFER 18-27-0 + B is also a good fit for autumn placement.
Foliar micronutrients help maximise early biomass
Once the crop is up and has reached the 2-4 leaf stage we need to maximise its growth pre-christmas to ensure there’s a decent amount of biomass to go into the winter with. This can be helped with micronutrient applications. The easiest way to apply all of OSR’s key nutrients required in the autumn is to use a multi-nutrient, crop-specific product such as YaraVita Brassitrel Pro. It contains Mg, Mn, Ca, B, Mo and a small amount of nitrogen which are all vital to OSR growth. Trials have shown an application in the autumn gives, on average, a 0.3t/ha yield response over the past 5 years – that’s nearly £100/ha in yield.
So, in summary, there are many ways that nutrition can help improve establishment of OSR this autumn to help it get off to the best start possible and keep its momentum going up to winter dormancy.
The following fertilisers are recommended for autumn application to enhance oilseed rape establishment