Early hit on cover crops for spring barley establishment
Trials at the eastern counties’ Syngenta Innovation Centre have shown the timing and method of cover crop destruction, along with crop drilling techniques, could have a huge impact on the success of spring barley establishment this season.
Cover crops on ground destined for spring cropping, where conditions allowed sowing, will have played a hugely beneficial role over the winter, to help restore soil structure, build organic matter and dry out saturated soils.
But, with continued atrocious weather conditions, one of the challenges for spring barley growers is when, and how, to now destroy the cover. And in a timely manner that will maximise the benefits, yet still enable drilling.
The Rougham trials’ site compared different timings for destruction on a very thick rye + vetch mix and a less vigorous radish + oats cover, coupled with establishment by cultivation drilling or direct drill.
Results with the very thick cover crop highlighted the crucial importance of earlier glyphosate destruction, in mid-February, to ensure good seed to soil contract with both establishment techniques, reported Syngenta Business Manager, Mike Welby.
“Where the glyphosate treatment was delayed until immediately pre drilling in April, or not used at all, establishment was severely compromised, especially with the direct drilling.”
“Mechanical destruction by cultivations in preparation for drilling (above) gave better results in the vigorous cover, but still behind the earlier glyphosate timing,” he added.
With the initially less vigorous radish + oats the glyphosate timing was less crucial, but still benefitted from the earlier February timing, compared to mid-April pre-drilling.
“Where the spring barley was drilled direct into the radish + oats without any form of destruction, the oats continued to grow well and severely competed with the crop,” he pointed out. “Although they were subsequently controlled with Axial Pro, there was a significant impact on the final yield.”
Mike added that in other trial plots with glyphosate destruction (above, early destruction of vigorous rye + vetch), the direct drill proved a benefit over cultivations pre-drilling, as a result of better moisture conservation through the dry establishment period in the spring. These trends were also seen in plots with no cover crop sown over the winter.
“The negative impact of moving soil was particularly evident in the dry spring last year. It was also evident that the cover crops had removed soil moisture, which in the extremely dry season had some further impact on the crop establishment.
“Drying out soils might be beneficial where conditions are saturated, but in a more typical season the early removal with glyphosate reduces moisture lost and reduces the residue you’re drilling into.
“Best establishment was where cover crops were sprayed off earlier,” he advocated. Further trials are being repeated at Rougham this season, assessing the implications of the wet season for cover crop destruction.
Soil health enhancement
Mike also pointed out that cover crops have been eligible for Ecological Focus Areas, as part of qualification for BFPS and as options in agri-environment schemes, provided they complied with the rules. “How this changes in the future remains to be seen, but all the signals are for a world where greening, soil health and environmental schemes are given even greater emphasis,” he said.