When tillage is then used for seedbed preparation on burned CRP then the soil is highly exposed to erosion. Also, several plant nutrients can be lost via burning. Haying or grazing existing vegetation to remove it, chopping it and then treating with Roundup to kill existing vegetation is perhaps the best alternative. The management of old grass residue should start in the late summer and fall prior to the planned next year's cropping season. Also, certain perennial weeds are best controlled and killed by herbicide treatments in late summer and fall.
Spring is a difficult time to get satisfactory control of most perennial weeds.
Alfalfa in the CRP stands are best controlled in the fall compared to spring application. In summer, management of existing vegetation is best completed in late summer and early fall prior to contract expiration. If growers plan to use tillage alone, problems with existing vegetation can and will be a problem the first cropping season. Both nitrogen and phosphorous will be low or limited for maximum irrigated crop yield potential. It is critical to take soil samples and have then tested to ensure that adequate levels of nutrients are available for an irrigated crop.