Plough set-up key in effective blackgrass management

Plough set-up key in effective blackgrass management14 August 2017

How the plough is set up and used as part of a blackgrass control programme will make a significant difference to its effectiveness on north eastern farms this autumn, according to ProCam regional technical manager Nigel Scott.

“Repeated use of non-inversion cultivations, along with periods of heavy rainfall, can often create an upper ‘cultivated’ layer on the surface and a denser ‘uncultivated’ layer beneath, through which water is unable to easily escape, he explains. “This traps water in the upper layer like a sponge, with soil becoming starved of air.

“Since blackgrass is a marshland weed that grows in the cold, this combination of retained water and anaerobic conditions favours its growth over that of the crop. The hard, airless land also hinders root development in the sown crop, affecting its ability to compete.

“By not rectifying the situation, we estimate control may be compromised by up to 50%.”

According to Mr Scott, ploughing must be part of a programmed approach and used according to each field situation. When ploughing is the best tactic, it must be done right to be effective.

“If you have large levels of surface seed then ploughing them down is a sensible approach, he says. “If most of the blackgrass seed bank is lower in the soil profile, surface cultivations would be a better alternative to ploughing.

“When it is the right situation to plough, don’t just think of it as burying blackgrass, but instead use the plough to break down any double density layers to ensure the soil profile is well drained and aerobic.

“This will require careful set-up and operation of the plough to open up the soil structure. The attention to detail required to achieve this should not be overlooked.”

As a general guide to effective ploughing for the best blackgrass control, ProCam offers ten simple tips:

  • Are the skimmers at the correct depth and angle / do they turn in enough?
  • Are the skimmer points starting to wear, which could compromise their effects?
  • On a slatted mouldboard plough, are the slats wide enough to help break up the furrow?
  • Do tailpieces need fitting to mouldboards to properly invert the furrow?
  • Are furrows too wide? Would narrower widths give a better inversion?
  • Are the correct tyre sizes being used to sit properly in the furrow – thereby matching the bodies of the plough without creating gaps?
  • Does your ploughing speed produce optimum trash inversion – not so fast that black-grass seed is simply thrown back onto the soil surface?
  • After ploughing, don’t allow land to dry out before pressing. This makes breaking it down to create an open structure much more difficult.
  • Plough in optimum conditions. Ploughing when land is heavy and sticky doesn’t work, and is why some people turned away from ploughing in the first place.
  • Adjust ploughing direction according to wind direction – to ensure any seeds that are thrown on to the surface are blown on to the stubble, not the land you have just ploughed.

“It’s also important to check that what you set out to achieve with ploughing is actually happening,” concludes Nigel Scott. “This is best achieved by regularly checking the performance of the plough and how well it is inverting the soil when it is working in the field, as set up often needs to be adjusted according to conditions.

“In addition, carry out mole draining to remove excess water and ensure the drill is set up properly to avoid gaps in the crop that blackgrass can colonise.”