2022-2023 Cover Crop Growth and Tillage

Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu

For all crops, initial establishment is as important as fertility in maximum yield. The same principles adhere to cover crop growth, with earlier establishment and good seed to soil contact necessary for good coverage.

To examine growth using drone imagery, we flew rye cover crop fields over the winter of 2022-2023. This includes fields that were broadcast and turbo-tilled, broadcast no-tilled, and applied aerially. Although growth had started strong in the fall, a drier winter may have prevented better growth by March, with field variability apparent in all images (Figure 1). Some of this variability could be attributed to landscape (soil moisture), while other sections of the field had more available N following corn.

When plant growth was sampled in March, one of the broadcast/turbo-tilled fields (Figure 1a) had the highest rye biomass (up to 935 lbs. per acre) of the fields. The lowest biomass measured was in the aerially applied soybean field (max = 143 lbs. per acre), where fodder from the combine may have reduced emergence. The other turbo-tilled produced up to 513 lbs. per acre while the no-till field had a maximum of 396 lbs. per acre.

This small study is from one year and only a few fields but does support that greater growth occurs with good seed to soil contact. Particularly in fields with greater residue on the surface, the addition of surface tillage could increase the success of a cover crop.

4 field drone footage of rye cover crop establishment

Figure 1: Fields in March 2023 of A.) turbo tilled rye cover crop after rainfed corn, B.) no-till broadcast rye after irrigated corn, C.) Flown on after full-season + double crop soybeans and D.) Turbo-tilled rye after irrigated corn.