Carl R. Crozier1, Alan D. Meijer, Samuel C. Reberg-Horton2, and George Place2. (1) Soil Science; Vernon James Research & Extension Ctr., North Carolina State University, 207 Research Station Road, Plymouth, NC 27962, (2) Crop Science, North Carolina State University, 4411 Williams Hall, Campus Box 7620, Raleigh, NC 27605
Legume cover crops are being re-evaluated in North Carolina as potentially cost effective N fertilizers for conventional farms and as acceptable N sources for certified organic farms. Winter annual legume cover crops have contributed 100+ kg N/ha in numerous research trials, but a renewal of interest by commercial farms is leading to new management questions. Crimson clover (Trifolium incarnatum L.) may represent less of a weed problem than hairy vetch (Vicia villosa), but may be less productive in poorly drained soils. Planting dates within the optimum September planting window may require aerial overseeding into standing doublecropped soybean (Glycine max L. Merrill) to supply N for the following corn (Zea mays L.) crop. Results from a moderately well-drained coastal plain site and poorly drained tidewater sites suggest that crimson clover growth is limited on poorly drained sites. Overseeding prior to soybean leaf drop (September/early October) resulted in better stands than did overseeding at last soybean cultivation (August) or drilling after soybean harvest (November). Corn grain yields and the apparent N contribution to the corn crop will be presented.
