Summer Cover-cropping Treatments for Enhanced Winter Vegetable Crop Nutrition, Growth, and Yield

Summer cover crops of cowpea (Vigna unguiculata) or marigold (Tagetes patula) were tested against a summer fallow control for effects on soil and crop nutrition, growth and yield of a subsequent broccoli crop. Results showed that summer cover cropping enhanced soil organic matter content, soil and crop nutrients, crop growth, and marketable yield compared to the fallow system. Soil nutrient contents were low at the initial samplings stages, increased following cover crop incorporations, and were low at vegetable crop harvest. Higher soil NO₃ after cover crop incorporations was a likely indication of nutrient mineralization. Soil and crop nutrients, growth, and marketable yields increased with increasing years of cover cropping rotations, indicating their build-up effects. Growth and yield of the subsequent crop was more pronounced with cowpea cover cropping than marigold.