Monday, October 27, 2008
A cover crop is a crop not grown for the sake of harvesting but rather to benefit subsequent crops. Because we don't use any synthetic fertilizers cover crops are especially important to us for the role they play in "fixing" atmospheric nitrogen and retaining and recycling nutrients from previous crops. Of course one of the most important functions of any cover crop is to keep the soil covered, therefore protecting the soil from erosion. For summer cover crops this year we planted sunflowers, cowpeas, and buckwheat. We really enjoyed the sight of all the cheery sunflowers, and the bees sucked up their nectar along with that of the buckwheat blossoms. Currently we're planting crimson clover -- another pretty flowering cover crop -- and small grains (barley, oats, and rye). Crimson clover, like cowpeas, is a legume and a nitrogen fixer so it is an important cover crop to precede nitrogen-hungry crops like corn. Small grains, in contrast, are great in terms of the amount of organic matter they add to the soil and their general improvement of soil tilth. Small grains also offer succulent winter grazing for our milk cows to enjoy. A neat concept we're still trying to work out is the use of oats as a winter-kill cover crop. Potentially oats can yield much of the value of any small grain in the fall and early winter before dying back to a straw like mulch on the soil surface. This offers the possibility of planting directly into the dead cover crop without tilling first. If this doesn't work as planned, we may harvest some oats next spring.