Calcethorpe Updates Early May and February 2017
Cover Crop Update: Early May 2017The Effects of Termination Timing/Method
At the demo site, we have tried several different termination methods before the spring barley crop was established. This included drilling into the green, varying time intervals from spraying off to drilling and a split glyphosate application. Unfortunately due to the weather the planned interval dates were longer than desired and this trial subsequently has shown very little. The split glyphosate application (½ before Christmas and ½ in early February) also showed very little partially due to weather conditions this season but also due to small levels of biomass. However the area where we drilled into the green has produced a very interesting outcome.
The establishment of the spring barley crop has been effected when
following the single cereal species cover crops (oats, rye and
triticale). This area was drilled into the green. I believe this is a an
example of the high C:N ratio in cereals and subsequent temporary
nitrogen lock up. However a SMN sample has been taken to try and confirm
this.This was not seen in the mixes containing
oats/rye/triticale sprayed off with a 4-6 weeks gap before spring cereal
drilling. It is important to note that the spraying off timing is only
crucial when a cereal cover crop has been used before a cereal
commercial crop. The white mustard plots were also showing similar
visual symptoms however to a much lesser extent and are now not visible.
Again white mustard has a relatively high C:N ratio suggesting
temporary N lock up.
Cover Crop Update: February 2017
Spring Cropping for Blackgrass Control
Cover Crop Termination
Chemical destruction is the most common method with glyphosate being most widely used. Ensuring the rate of glyphosate used is appropriate to the level of biomass and the use of wetters and spreading agents can greatly improve efficacy of the glyphosate application. Where rye has been used in the cover crop mix, termination must occur 4-6 weeks prior to the drilling of a following spring cereal crop.
There are many ways to destroy cover crops and deciding which method you use, ultimately will depend on the overall aim of using the cover crop in the first place. E.g. soil health improvement, better soil structure, weed control or for nutrient capture.
Mowing and Rolling can be used to aid with biomass control and help increase the plants sensitivity to frost. However a following herbicide application is often needed to prevent regrowth.
Grazing is becoming more popular. High numbers of sheep for short periods of time, with a good shepherd to prevent poaching is the key to the success of grazing cover crops. You do not want to graze to bare ground, simply graze enough to make the biomass more manageable. Also renting out cover crop land for £3-£5/head can at least pay for the seed costs in most cases.
It’s a numbers game!!
Do not rush into sowing spring cover crops where blackgrass populations are high, remember why you are sowing this crop… for blackgrass control rather than spring crop yield! Spring cereals actually establish very well in April, and April emerged blackgrass will produce 95% less seed than October emerged blackgrass.
Getting your seed rates and drilling timing correct is so much more effective for blackgrass control then any chemical can. Consider chemical control to be your final step to use against the blackgrass, not the first!
3 key points from the open day on spring cropping for blackgrass:
1. Spring barley is 7x more competitive than spring wheat
2. It is paramount that you know your percentage establishment on heavy land
3. Get your seed rates correct!
a. Aim to have 300 plants established before end of March
b. Aim to have 350 plants established if emerging for after the end of March. This is because they have a lesser ability to compensate in the grain sites/ear to build yield.