Improvements to field drainage can provide a big boost for black-grass control programmes with better crop establishment and more days of travel advises Bayer CropScience.
After harvest, when fields are clear and before winter cereals are drilled, is a good time to investigate any drainage issues and take steps to put them right.
“It’s a busy time of year, but it’s definitely a job to try and fit in,” says Ben Giles of Bayer, “many of the growers we speak to find that poor drainage and poor weed control seem to come together.”
Soil expert, Philip Wright, explains: “If you get any drainage problems fixed then your soil structure and to some extent the weed problems will be improved, particularly with black-grass being a marsh-loving plant.”
Poor drainage strikes a double blow against the crop; firstly crops don’t establish and grow as well in wet waterlogged ground, secondly these conditions provide opportunities for black-grass and some other weeds to get established and out-compete the crop. The consequences of this are, of course, reduced yields and effectively a reduction in the cropable area on-fam.
Correcting any problems often seems like a large, costly job – and when it involves installing a new drainage system across much of the farm this is true. But there are plenty of smaller, cheaper steps people can take to get drainage in order, according to Philip Wright.
“Maintain what you’ve got – make sure ditches are clear – it sounds obvious but it has to be done. Also check outfalls – quite often, over time deposition of sediment raises the level of the ditches above the level of the outfall, so you might need to lower levels to below the outfalls.”
You can also jet out the drains – although this doesn’t work on all systems. After doing all routine maintenance, you can work out if any part of the system needs updating.
Philip recognises that, nowadays, it is more common to treat the problem than drain the entire field – this is fine as long as you prepare properly and understand what is causing the issue.
“It’s good to look at field history and old drainage maps because often that gives you a good clue about the underlying problem, for example, where two fields are joined a ditch could have been filled in or you may see a low area which used to be an old pond,” says Philip.
The other huge advantage of well-drained land is that it will have more days when it is suitable for travel – this is especially important in spring when growers are waiting for land to dry out to begin their weed control programmes.
“For people dealing with black-grass, delayed drilling is now the norm – however, this means that post-emergence sprays like Atlantis WG often go on in spring,” says Ben Giles. “For the product to be effective it’s important that the weed is small so being able to get on land early is a huge benefit,” concludes Ben.
