Cover crop and nitrogen rate management practices influence corn (Zea mays) NDVI and nitrogen content

Cover crops are rarely adopted in the northern Corn Belt because of short growing periods but could provide benefits when grown between wheat (Triticum aestivum L.) and corn (Zea mays L.). We evaluated corn NDVI (normalized difference vegetation index) and leaf N (at six leaf, ear leaf, 75% silk, and physiological maturity), over three growing seasons in response to factorial treatments of cover crop (annual ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot], radish [Raphanus sativus L.], and no-cover control) and N rate (0X, 0.25X, 0.5X, and 1X) relative to the recommended rate based on pre-plant soil tests (157–190 kg N ha–1). Grain N was also measured in the last study year (2016) to evaluate if leaf N indicated grain N. Radish cover crop increased corn NDVI relative to the no-cover control, but annual ryegrass decreased NDVI relative to no-cover control. This response to cover crop treatment suggests that radish cover crop may improve corn nutritional status. Corn receiving...