Getting the best return from second-cut silage

Ensuring that there are adequate fodder reserves in place for next winter is something each individual farmer needs to focus on throughout 2024 rather than being reliant on purchasing feed next winter to fill a deficit.

Many farmers took early crops of first-cut this year, so maximising second-cut silage provides an opportunity to build reserves for the coming winter. Ensure that second-cut crops receive adequate fertiliser to drive good grass yields at harvest time.

Nitrogen and other inputs

Where there is availability within the total farm nitrogen (N) allowance, farms should optimise crop returns (4t DM/ha) by applying a total of 100kg N/ha, which will come in the form of both cattle slurry and chemical fertiliser. If second-cut fertiliser has already been applied at a low rate, a top-up of N (protected urea) can be applied.

Phosphorus (P) and potassium (K) requirements should be applied via cattle slurry where available. Apply at 2,000-2,500 gallons/acre using low-emission slurry spreading (LESS). Where cattle slurry isn’t available, P and K should be spread at a rate of 4kg P/ha and 20kg K/ha per tonne of grass dry matter (Table 1). Where a farm does not have a P allowance, apply straight K. Sulphur (S) has shown both improved grass DM yields and quality as it helps to maintain an optimum N:S ratio and allows N to be used more efficiently. Second-cut grass silage crops have a requirement of 12-15kg S/ha.

Table 1: Second-cut silage N, P, and K requirements (offtakes) based on grass yield (DM) and fertiliser programmes

¹Apply 4kg P and 25kg K per tonne of grass DM. ²N, P and K advice for crop offtakes based on grass DM yield at harvest time. ³Apply additional P and K for soil fertility build-up after grass harvest.

This article by Dr Joe Patton, Teagasc Head of Dairy Knowledge Transfer, first appeared in the Teagasc Dairy Advisory newsletter for June. Access the full publication here.