Planning your crop nutrient requirements

Well managed soils together with a nutrient management plan to balance the requirements of the crop based on yield and potential for growth will ensure that there is enough quality forage is in the clamp next winter.

1. Test slurry – the actual value of slurry on each farm varies depending on the diet of the cow, very often the best time to take a sample is when it is mixed, the real value of slurry can then be taken into account in the nutrient management plan. Slurry testing pots available now! If you have not had the soil tested it should be done before FYM/slurry applied.

Application method has a huge effect on the amount of nutrients that are retained for the use of the crop, the real “cash” value of slurry is at the point of spread – a value that can range from a minimal 5% loss using an injection system to about 50% loss when using a splash-plate.  Consider alternative methods and focus on areas where the soil results indicate there is a crop requirement for the valuable Phosphorus and Potash elements of FYM.

2. In basic terms to estimate the required nitrogen, work back from the estimated cutting date and account for any clover in the field. From the day you are applying fertiliser use the calculation of 2.5 kg. /Ha (2 units/acre) per day from the date of application to the date of cutting.  Allow some flexibility in this to allow for dry or very cold periods, minus the value of the slurry applied. Focus on fields that will give the best return, new leys and ryegrass will have a good nitrogen use efficiency compared to older pastureland.  This should be part of the nutrient management plan as taken from RB209.
3. Check for compaction, tractor or cattle trampling can adversely affect yields, this could be up to 37% of the potential. Soil compaction influences many physical and biological soil properties and processes. If there is clear evidence of compaction through conducting a visual inspection VESS then consider options for alleviating the problem depending on the depth of the compaction, on grazing ground its likely to be in the top layers of the soil 10 cm, in which case spikers or slitters will work well in the right conditions. If the compaction is deeper then a sward lifter which works between depths of 20-35cm, this is a more costly exercise and needs to be carried out in the right conditions. Timing is critical for these operations.  The best cure is prevention where possible.  Consider controlled traffic to reduce the amount of compaction, tyre pressure and width and soil type also have a contributing factor to prevent compaction.