Effect of autumn and winter mycorrhizal cover crops on soil properties, nutrient uptake and yield of sweet corn in Pennsylvania, USA

We investigated the effects of an autumn sowing of contrasting cover crops (oats, rye and a combination of oats and rye) on soil aggregate stability, mycorrhizal colonization, phosphorus uptake and yield of sweet corn planted the following summer. Rye is a common cover crop in the middle Atlantic region of the United States of America. It grows slowly in the autumn, survives the winter, grows rapidly in the spring and flowers in the summer. Thus, herbicide is commonly used to kill rye prior to planting spring crops. Oats, in contrast, grows rapidly in the autumn but is killed by frost during the winter. Thus, with oats, potentially less herbicide is needed to prepare the field for spring planting. When compared to fallow, oats was as effective as rye in increasing mycorrhizal colonization of sweet corn, density of mycorrhizal hyphae, and soil aggregate stability. An oats cover crop may thus be a viable alternative to rye. The combination of cover crops (rye and oats), however, was significantly better than single species of cover crops in terms of sweet corn mycorrhizal colonization, P uptake and yield of sweet corn.