The Met office recently released the data for autumn rainfall compared to the 30 year average and whilst it’s no surprise that most parts of the country have had at least 130% of their average autumn rainfall, making a prediction on the impact that this will have on nitrogen available for the 2020 crops is much more difficult. For many areas, crops where they have been planted have grown quite well and taken up more nitrogen than in drier colder years. Spring cover crops will have had the same effect and will have reduced leaching.
Whilst it is possible to estimate the amount of Nitrogen available from specific field information (The Field Assessment Method) testing for Soil Mineral Nitrogen (SMN) may this year be more beneficial and will help planning the crop requirements and fertiliser applications. SMN testing is more applicable where crop residues or manure have been incorporated and on lighter land where losses may have been greater.
To obtain best results from Soil Mineral Nitrogen testing, it is important that representative samples are taken from the field at three depths and that the samples are refrigerated and submitted to the laboratory immediately.
Many slurry stores are bursting at the seams and in some cases spreading has occurred when and where it has never happened before. This makes planning the fertiliser applications more difficult.
Knowing the nutrient content of the slurry is important if accurate applications are to be made. Some contractors will routinely carry equipment to measure the nitrogen content of the slurry. If this is not available to you then laboratory analysis for a sample as it is being spread, make sense so future applications can be adjusted.
For more information on tests for Soil Nitrogen Supply and slurry analysis, contact your local FCG office or William at email@example.com.