With fertiliser prices increasing by £70 per tonne, or more, compared to the summer, it is all the more important to ensure that you plan correctly for individual crops so that you are using the right amount of fertiliser to achieve the desired yield and quality.
The base of any fertiliser plan has to be soil analysis to establish the phosphate and potash levels. Once these are known they can be balanced by applying either organic manures/slurries or inorganic fertiliser. Whilst it can be tempting to take a P and K holiday, this should only be for one year, especially if harvesting crops off the field, e.g. silage or cereals. P and K are taken away when compared to grazing, which sees an element of the P and K returned by the animals.
If soil indices are very low, then using slurry or FYM can be very economic in helping to increase indices back to the desirable levels. Applying 10 tonnes of FYM per acre can save you £150 per acre in fertiliser costs, or 2,500 gallons per acre of slurry can save £40 per acre.
We have recently seen problems where P and K indices have got too high, into the 3 and 4 brackets. This was caused by continuous applications of slurry and FYM over a number of years on fields that are easily accessible for spreading. The knock-on effect of this is the locking up of trace elements which will impact on livestock performance, DLWG, milk yield, fertility, etc. In this case, a detailed soil analysis has been carried out to look at how the trace elements are interacting and put a plan in place to release locked up minerals.
I am currently writing a number of fertiliser plans for our clients ready for the 2018 season. If you are interested in looking at this for your farm, please contact Phil Cooper at firstname.lastname@example.org or your local FCG office.