Experienced crop farmers know that if they want to keep their soil fertile and healthy from year to year, they should enlist the help of a good cover crop. Cover crops such as rye grass or alfalfa, planted in unused plots over the non-growing season, provide a host of benefits: reduced erosion, fewer pests, increased mineral content (thanks to their deep roots), and valuable organic matter (when converted to mulch or compost). Plus, they reduce the need for synthetic fertilizers and other expensive amenities.
Managing Cover Crops Profitably, 3rd Edition, published by the Sustainable Agriculture Research and Education program, can be downloaded from their website, and includes expert advice from researchers and farmers nationwide. There are farm profiles, seed sources, and region-specific recommendations. Print copies are available here.
For more advice on cover crops and soil health, read Build Better Garden Soil, and 8 Strategies for Better Garden Soil.