How to make quality grass silage

Producing high yields of high quality first cut silage reduces the need to maximise second cut silage, whilst allowing you to substitute expensive bought in concentrate feed with higher quality silage to achieve comparable levels of performance. The potential exists to produce 6 – 7 t/DM/ha from a first cut ryegrass sward if the proper fertilizer programme is in place. 

Nitrogen drives crop growth but also crude proteins levels in grass silage. Some of the crops N requirement will be met from slurry but the inconsistency in slurry N levels and the losses experienced during application usually result in over estimating available N supply. The optimum application rate for first cut ryegrass sward is 125 kg/N/ha, so you need to subtract your slurry N contribution from 125 kg to obtain the quantity of purchased N. 

Sulphur is being under applied on all grassland, but particularly for silage. Sulphur deficiency is compromising grass DM yield and silage protein levels. Soil supply is inadequate and 40 - 50 kg/SO₃/ha should be applied for first cut silage. 

Low soil phosphorus and potassium will reduce herbage yield and N use efficiency. A high yielding crop requires 55 kg/ha of P₂O₅ and 180 kg/ha of K₂O. Cattle slurry can supply a large portion of this requirement with the balance coming from purchased fertilizer. It’s a false economy applying too little P and K. 

For more information check out Yara’s silage programmes