Falling farm profits are the likely and unwelcome outcome of attempts by growers to save money on fertiliser and lime inputs.

Fertiliser holidays can jeopardise crop performance, warns Masstock's David Langton

So says Masstock's David Langton, who's worried that tightening arable margins are forcing farmers to review their use of major nutrients and jeopardise crop performance.

“Farming under the Single Farm Payment scheme means identifying where crops can be grown profitably and then growing them well,” he says. “With tight margins, growers are looking at input costs and trying to work out where inputs can be cut without impacting on final yield. To many farmers the most obvious apparent cost saving lies in stopping or reducing phosphate and potash (P and K).”

But there are real risks in taking P and K 'holidays'. Optimum plant nutrition is key to high performing crops as well as sound environmental practice. Fields which are index 0 or low index 1 for P and K are unlikely to achieve full yield potential, even if the recommended rate of fertiliser is applied.

“P and K Holidays should only be taken if soil reserves are adequate - over Index 3 for both - for a limited period without yield dropping off and will require careful management. Regular soil sampling to assess nutrient availability and the volume of crop take-off is also important in considering a cut in fertiliser application,” says David Langton. And he reminds growers that if indices of major nutrients are allowed to fall it can take a long time to build them up again. “And while the indices are low, crops will not perform at their best.”

Keeping a check on soil indices is now a crucial aspect of cross-compliance, he adds. “Fertiliser Management Plans are going to be compulsory, but they should not be seen as more negative red tape. Good nutrient management is key to good crop performance as well as helping to protect the environment. There's an added value in putting one together as it will earn you Entry-Level Stewardship Points.”

Growers making use of organic manures will have to do a Manure Management Plan as well. Don't underestimate their valuable nutrient content, especially given current fertiliser prices, Mr Langton stresses. “An added benefit is that they help to build soil organic matter, improve the workability and nutrient availability of soils.”

Keeping a check on pH levels is also important, he adds, and lime use is another area where growers would be ill-advised to consider cutting costs. “Lime is of equal importance to fertiliser, with low pH conditions curtailing crop performance.

“The whole concept of fertiliser holidays, and for some even fertiliser retirements, poses a real threat to farm profitability today and for the longer term is a threat to the crucial resource of national soil fertility.”