17 February 2021, UK: Good cover crop destruction will help to pave the way for successful spring cover crop establishment.
With any EFA restrictions now finished, Kings Crops specialist, Richard Barnes (below), advises growers’ attention can now turn to techniques to get on with timely destruction.
“If you have frost-sensitive species such as buckwheat, phacelia or mustard, you may find that recent hard frosts will do a good job of destroying the crop for you.
“However, more robust, winter-hardy species such as radish, vetch and cereals will still need specific attention.”
Full inversion with the plough may be the preference for some, however, this can go against the principle of minimising soil movement to help maintain and develop soil fauna, he pointed out.
“Flailing will reduce the bulk, whilst the crimping or rolling can work well in conjunction with prolonged frosts – which has seen many growers out at night with the rolls on frozen surfaces in February.
“However, it’s important to remember that rolling will not deal with full crop or weed destruction alone and will always need to work alongside another method.”
Mr Barnes highlighted that grazing cover crops can be a successful in removing biomass and to generate an income stream, as well as converting into more readily available nutrients. However, he warned that success will be dependent on soil type and ground conditions – heavier soils should be avoided as the work done by the cover can soon be undone by the sheep’s feet.
Another important factor to take into account with livestock grazing, particularly with spring barley, is the need to prepare a Livestock Manure Nitrogen Farm Limit and crop nutrient plan.
In most situations, the use of glyphosate will help to deliver an effective and integrated opportunity, advocated Mr Barnes.
“A herbicide will enable the efficient removal of both sown and weed species and is particularly beneficial for addressing grassweeds at the same time.” However, crops with very large canopy or biomass may in certain instances require a second application, which needs to be allowed for with destruction timing.
“Working back from your target drilling date by a minimum of six weeks will ensure that the active has adequate time to break down the crop canopy along with any weeds. This will then help to create the best medium to drill the following crop into.
“If you are taking a direct drilling approach, or you aren’t drilling your following crop until later, you may be able to leave your cover crop in the ground for longer to increase crop biomass and rooting activity,” he advised.
“For growers undertaking more conventional methods, and particularly on heavy soil, it is usually more preferable to drill your following crop as soon as conditions are favourable.
“In this instance, removing the cover crop at the earliest opportunity will allow time for the biomass to break down. It will also ensure your seed bed has had chance to dry out after spraying, to ensure rapid establishment of the next crop.”