Cutting grass for silage early this spring is a worthy consideration, particularly if there continues to be a lack of useful rain, according to Ecosyl silage specialist, Peter Smith.
But, where rain has arrived, watch out for luxury uptake of unused nitrogen fertiliser into the crop before cutting, which could, otherwise, buffer the fermentation.
Smith said he has received a number of enquiries from farmers recently asking what to do where grass growth has stalled due to the dry weather.
Cutting grass early for silage or leaving it in the hope that it will bulk up are the only options available, he has advised.
Grass quality
“If you leave it, and conditions remain dry in your area, there is a risk that both quantity and quality will suffer as the grass starts to dry out and die back.
“If the grass becomes stressed due to drought, there is also a risk it will start to produce seed heads prematurely, which also compromises quality; and turn white in the base, which will affect its ability to regrow.
“Alternatively, by cutting silage fields early, you could still harvest a reasonable crop and have your first cut safely banked. By leaving green stubbles, it should also be easier for it to regrow.”
Caution
But, be careful too, he warned:
“It may wilt faster than you think. With a lack of rain, the grass may already be at around 20% dry matter (DM) stood in the field.
“So, if you mow in the morning and ted it within an hour, it might hit a target of 30%DM that same afternoon and be ready to harvest that evening.
“The other thing to consider is, if you leave cutting for a fortnight and rain settles in, you may not be able to get back in the field to cut it before the end of May.
“But, whenever you cut, remember the potential for unused nitrogen to be present in the crop, which will buffer the fermentation.
“Grass should contain less than one part per 1,000 of nitrate before cutting. To boost the fermentation, wilt to a DM at the top of the normal range of 28-32% DM and use a proven additive.”
Ultimately, cutting decisions should be made on a field-by-field basis, and it may be a case of cut some and leave others, said Smith.
Other considerations include checking whether slurry has been adequately washed in before cutting.
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