Jim Dickrell
It might not be intuitive at first, but corn silage digestibility improves with soil conservation practices that involve no-till farming and cover crops.
“After 5 years of no-till plus cover crops, corn silage digestibility increased by 2-6% in 2018 and 2019 in comparison to silage grown in a conventional tillage system without cover crops,” says Jason Cavadini, an agronomist with the University of Wisconsin Marshfield Experiment Station in northcentral Wisconsin.
“In the last two years of our trials, we started detecting increased digestibility in feed quality with interseeded crops,” he says. “And we were sure we were not getting mixed feeds from the interseeded crops in our corn silage based on how we were harvesting the silage.”
In the first four years, Cavadinia saw soil health improve but did not detect any yield differences. In the next two years, he saw forage quality increase, which he attributes to soil health and improved biology.
“The difference in feed quality came from the corn silage itself that we were measuring in our plots,” he says. “Our running theory, with consecutive years of minimum tillage and green cover crops, is that we are getting levels of biological activity in the soils we haven’t seen in a long time and that is being reflected in our crop quality.”
No-till and cover crops have not had an effect on crop yields. In terms of production costs, Cavadini says most farms try to limit planting and seed costs to $30/a. This can be recouped by saving two tillage passes. It can be more than recouped if farmers are taking a cutting of cover-crop forage.
The first benefit farmers see with reduced tillage and cover crops, however, is that fields can carry heavier traffic. In years with wet autumns, that can prove a huge benefit to getting crops harvested. It also reduces, and often eliminates, the need for spring tillage ahead of planting.
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