National Blackgrass Centre of Excellence
National Blackgrass Centre, Brampton, Cambridgeshire, 2017
A wet harvest usually means disastrous rutting and damaged soils heading into autumn cultivations. However, for many growers this harvest, this is not the case as practices that they employed two or three years ago to reduce their black grass populations, have also brought about improved soil health benefits.
Managing for black grass and maintaining healthy soils run in parallel, and the outcome is inevitably higher yields; through healthy soils, drainage will be improved, thereby reducing black grass, soils will store more water and crops will yield better, says Dick Neale, Hutchinsons technical manager.
However, it’s all about a comprehensive approach using the five principles of black grass control that we developed at Brampton, but if only 3 of the 5 are carried out then the results will not be nearly as good, he points out.
5X5 Approach to Black grass Control and Healthy Soils
1. Rotation and Crop Choice: Spring cropping (especially barley) offers a wider window for autumn black grass control. Select competitive crops and varieties (e.g. hybrid barley) that can establish well in the farm conditions and compete with black grass
2. Seed Rate: higher rates boost crop competition – up to 550 seeds/m2. Allow for lower establishment when sowing late, or if spring cropping on heavy land
3. Delay Drilling: allows more time for black grass to emerge in autumn and be controlled before a crop is sown (e.g. through stale seedbeds) – around 80% of black grass emerges between September to November
4. Shallow Cultivations: restrict cultivations to the top 50mm of soil to maintain a “kill zone” where black grass can be stimulated to emerge and be controlled. Avoid bringing seed up from depth by ploughing or subsoiling.
5. Chemical Control: matched to the population remaining after steps 1-4, excessive use or need for herbicides indicates that other management practices have been inadequate, or that the levels of black grass are too high for the chosen cropping.
Learnings from Warboys RTC
One year on from taking on the tenancy of Red Tile Farm, Warboys, much has been learnt, and going into the new season some changes will be made to cultivations, particularly in relation to sugar beet, says Simon Wilcox, farmer and agronomist with Hutchinsons.
“We have found that some soils are heavier than we first understood them to be, which was disguised by the high levels of organic matter. In fact some soils have a clay content as high as 40%.”
“We strip-tilled the sugar beet crop last year, but have found that the soils are too stiff to be cultivated just the once. We really need to create a little more tilth for the drill to work on the clay soils, so this year we will look to strip-till to give us the depth required but with an additional pass using the Cousins surface cultivator.”
“We will also be sub-soiling some of the headland
areas, as we have identified areas of localised compaction that have
come about from loading sugar beet and potatoes in previous seasons and
unloading during harvest, as I have used a haulage grain service.”
Some of the sugar beet fields that we identified as green zones last year, have more of a black grass problem than we initially thought; this is where black grass emerged after the contact herbicide was applied, so we will be re-thinking the cropping on these and instead of following the sugar beet with wheat, we will grow spring barley to get on top of the black grass, Simon explains.
“This is also the case in spring beans where one of three fields has proved to be an amber zone at best and again, this will have to go spring barley.”
“It’s important for me to stick to the plan of managing rotations for black grass control although of course if I get the black grass control correct the gross margins will follow.”
Adopting a focussed black grass control and focussed soil health approach from the start has worked for Simon’s spring malting barley. His crop of Planet has yielded around 8t/ha, and produced the quality for malting.
“Screenings maybe greater than expected, but we think that this is related to a very high seed rate, so we will revisit this for the coming season. We will still use a high seed rate for black grass control but instead of 400 established plants /m² we will go for a slightly lower rate of 350 plants/m² as on-farm seed rate trials this year have given us confidence in higher establishment percentages than we planned on.”
While I am pleased with the spring
barley’s performance on black grass control, it has been a difficult season to
extract the best from the crop, comments Simon.
“Eight weeks with no rain disrupted uptake of nutrition and made PGR decisions very difficult. 70mm rain in 18 hours mid-June caused us real concerns, but the crop ‘nested’ rather than lodged and we did not see the low ear losses that have been a feature of many spring barley growers this season.”
Spring Cultivation Videos with Dick Neale:
The series of eleven short cultivation videos featuring Dick Neale at our black grass centre at Brampton, clearly demonstrating the effects of ‘conditioning crops’ and different soil management regimes on soil health, can be viewed on our video library.