03 June, 2017
Mid-season grassland fertiliser management
With current grass growth rates hitting the high 80’s (DM/kg/ha per day), it’s a challenge to maintain grass quality at this time. Grass is hell bent on setting seed so managing the grass wedge and maintaining low residuals is the key to maintaining milk yield and composition.
The recent ‘Grassland & Muck’ event at Stoneleigh highlighted how the recent dry conditions in April and May impacted on grass growth rates with many of the early season urea users suffering in the drier areas. This is no surprise as urea nitrogen is not immediately available for grass uptake and during dry conditions the conversion process is much slower. Some farmers were aware of this and switched to an ammonium nitrate (AN) based fertilizer early to kick-start growth as it performs better in dry conditions. AN contains nitrate which is immediately available to the plant.
We also took a lot of enquiries about sulphur application on grassland which was encouraging as we know how important sulphur is for productive grassland farming. My advice on the day was choose a nitrogen plus sulphur product, rather than straight nitrogen. The trial data is overwhelming in favour of sulphur applications, especially for early season growth. Don’t depend on organic sources of sulphur to supply your crops requirement.
Clover is coming into its own at this time of year but its nutrient requirements are not often considered. Clover is susceptible to sulphur and potassium deficiency so to get the best productivity from clover you need to supply these nutrients in a mineral fertilizer. NPKS products applied now will replenish the nutrients removed in earlier months and maintain shorter grazing intervals in mid-season.
