How to manage blackgrass when returning land to cropping from SFI options – South East Farmer

Farms with a history of blackgrass need to be aware of any unintended increase in populations that could have occurred within sustainable farming incentive (SFI) options and manage this accordingly as and when land returns to cropping, says Lizzie Batt, agronomist with Hutchinsons, based out of the Canterbury office.

For those considering putting land into an SFI option where blackgrass is a risk, growers may be better off in the longer- term by accepting the slightly lower payment and increased investment associated with stacking multi-species cover crop options (e.g. SAM2/CSAM2, SOH2 and SOH3), that allow for blackgrass control, rather than higher paid options such as winter bird food that do not.

The first step would be to sow a winter cover in August. That would be sprayed off in March, followed by a spring-sown cover crop, which would remain in the ground from March until June.

The next stage would be the summer-sown cover, lasting from June until August. The total support payment would be £455/ha per year, which is often better than spring bean gross margins.

This regime offers a break in rotation, plus three opportunities to bring blackgrass under control and the potential to provide a clean and fertile seedbed which would boost first wheat yields.

“Selecting the right mix is key to maximising cover crop benefits, with multi- species mixes providing more advantages than simple two-way blends, such as mustard and oats,” said Lizzie.

“Use at least six different plant species taken from three or four families. We have made some bespoke cover mixes that achieve the aims within Hutchinsons Maxi Cover range. The diversity of growth habit and root structure helps build a more resilient soil structure, and improves aeration and water management.

“The soil will have greater ability to store water lower down in the profile in times of prolonged drought. It will also ensure moisture is not lost closer to the surface through run-off in high rainfall situations.”

Lizzie went on: “If growing legume fallows in blackgrass situations, grow a mix containing grasses and legumes to increase competition. “They can be mown as required (with no restrictions) within the first 12 months once blackgrass begins to head, although continuous mowing can lead to blackgrass growth habit switching to a short profile and becoming more difficult to tackle.”

In year two, fallows can be mown between March and mid-June, leaving eight weeks uncut in the summer.