Lack of investment into farm drainage systems is holding back black-grass control, according to Professor Dick Godwin, visiting professor at Harper Adams University.
Speaking to an audience at Bayer’s black-grass hub, Prof Godwin said very few soils have been properly drained over the last 40 years after a government grant programme was retracted in the 1990s.
The high price of drainage improvement works has led to lack of motivation from both tenant farmers and landlords as old drainage systems start to degrade or require maintenance.
“Adopting low cost drainage options like mole ploughing into a field ditch or down into pre-existing mole mains is a good option for short-term drainage solutions,” said Prof Godwin. “The use of a mole plough will create channels in the soil to drive water downwards, helping to create a soil environment that is not conducive to black-grass.”
“Where weed problems are more serious growers should consider ploughing the seedbank down as a good starting point, followed by delayed drilling and increased seed rates. Only plough once so you do not bring the seed back up to the surface next year but try to create the right environment using drainage first.”
Also speaking was Tom Jewers who farms 360ha of arable land in Suffolk and has used mole ploughing as part of his black-grass control programme.
“One of the basic things we need to remember is that black-grass is a marshland plant so make sure drainage is well maintained. Drainage is very expensive so if you can’t put new drains in, getting a contractor in with a mole drainer at £90/ha is going to pay for itself.”
Bayer’s Darren Adkins was on hand to offer growers herbicide advice explaining that variability in performance from herbicides can often be put down to black-grass growth patterns that season.
Mr Adkins recommended Monolith as the product of choice this spring, which replaces Pacifica and Atlantis. He claimed that during trials, Monolith treated plots had 30 less black-grass heads per metre than areas treated with Atlantis.