Delaware Agronomy Blog

University of Delaware Cooperative Extension

Tag: nitrogen

Cover Crop Biomass and Termination Considerations

Jarrod Miller, Amy Shober, & Mark VanGessel

The benefits of cover crops to the following corn crop can include additional nitrogen (N) or weed suppression, but maximizing these benefits requires later termination to build greater biomass. These N and weed control characteristics are especially appealing this season as input costs are relatively high while supplies are relatively low. However, growers should take the time to estimate the additional costs of allowing a more robust cover crop to accumulate this spring, as surface residues reduce proper seed placement as well as limit seed to soil contact. This article will discuss the management of cover crops for both maximizing N benefits as well as weed suppression in the following corn crop.

Aerial picture of cover crop plots

Cover crop plots at the Carvel Research and Education Center.

Maximizing Cover Crop Biomass

Estimating the amount of N that could be available requires knowledge about 1) total cover crop biomass and 2) cover crop C:N ratio, both of which are affected by termination timing. The longer a cover crop is allowed to grow, the greater the amount of cover crop biomass will accumulate. Continue reading

Complete Wheat Tiller Counts Now for Spring Nitrogen Need

Jarrod Miller and Amy Shober

Wheat is beginning to green up and is showing minimal freeze damage when compared to last year. There is still some time for wheat to develop more tillers before the first node emerges above ground. Now is a good time to go out and check for adequate tillering to determine the need for early spring N applications. Timing nitrogen (N) applications this spring will be difficult due to the amount of rainfall we have received.

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