- Location
- Essex Coast
I have been direct drilling since 2001 and using the Dale seedhawk drill since 2003 very sucessfully as a dryland operation on 550 mm rainfall.
Until 3 years ago we sprayed off all wheat stubble in the early winter to save moisture for the following spring crop of barley but we have developed some irrigation as a community scheme was coming past the gate. So we now sow annual ryegrass or triticale straight into the wheat stubble without any glyphosate as a cover crop come winterfeed crop for fattening lambs. This crop is then terminated with glyphosate early spring and sown into barley about a week to 10 days later but now have the same issue happening that Simon C has noticed. If the grass is hard grazed and sprayed short the issue is not quite so bad but still there and almost kills the barley if the grass or covercrops has any size to it.
It seems I am creating a huge issue and has me really questioning the use of glyphosate or cover crops. My dryland system still had an application of glyphosate before drilling in the spring but really the weeds were very small and thin so didn't notice the effect that I do now. I will try terminating the green more than six weeks earlier but it will effect the premium we received for our lamps so may make that operation a waste of time and money.
Just thought I would share this with you for the same reason Simon C and others have as I see the use of cover crops is growing and want you all to realise the expensive lessons this may create if not done properly.
@kiwi Thanks for this, it seems your experience is just the same as mine. I did a trial two years ago where I flailed off one tramline in a cover crop in the autumn to give the same effect as grazing. The peas were not quite as bad there as where the cover was left over winter, both being sprayed before drilling, but both bits looked worse and yielded less than the rest of the field that was burnt off in November.
I agree, we need to try some cover mixtures that have no known allelopathic effects on the following crop, then we could be sure about the glyphosate. Monsanto's answer to this is that the problem is being caused by breakdown chemicals of roots and tops (Two Simons), but I am not convinced.