Early Maize harvest unlocks Cover Crop benefits

For north Somerset milk producer Jon Bult, growing a very early maturing variety of maize allows him to maximise his use of overwinter cover crops which deliver soil health benefits and an Sustainable Farming Incentive (SFI) payment.

Maize forms the basis of the ration for the 700-cow herd at Collum Farm as it consistently provides a high energy forage which contributes to yields of over 12,000 litres per lactation for the herd’s Holstein Friesians, and over 7,000 litres for the herd’s pure Jerseys. 

Despite being grown on some marginal land, plus the challenging growing conditions of recent seasons, growing 800 acres of early maturing Gema allows Jon to prioritise soil health improvement by maximising the area of overwinter cover crops that go into maize stubbles. 

“We’re on heavy ground, a lot of which land is marginal for maize,” Jon says, “so it makes sense to opt for the earliest maturing varieties. With cows inside all year round, we need high yields and energy. Gema is ideal for us as it delivers high starch, but its earliness does not impact significantly on yield. 

“We grow straight Italian ryegrass after maize and, being at sea level and with minimal risk of frosts, can typically drill this successfully as late as the end of October,” he says. “In the past, we’ve been able to establish grass with relatively light cultivations, but with increasingly wetter conditions we had to cultivate deeper to achieve success.” 

As a straight overwinter cover crop, established after maize, the Italian ryegrass qualifies for the Sustainable Farming Incentive action SOH4, which is currently worth £203/ha, although Jon believes the greater value is in the benefits to soil health. 

“Minimising soil erosion and nutrient losses is the main priority,” he says. “We’ll terminate the cover crop in the spring, and then apply farmyard manure and slurry before going back into maize. 

“We will be growing Gema again in 2025. If we had the ground, I’d like to grow more, including some grain maize again, but land is our limiting factor at the moment.”

In an ideal season, Jon aims to drill maize from around 20th April, though it has been later in the past two cold wet springs, even as late as 14th May. He uses a standard herbicide programme, with pre-emergence applications for the earlier drilled crops. He’s routinely soil sampling his fields on a four-yearly rotation, and reports the key indices to be optimal, but is considering foliar applied nutrition as a possible development going forward.