Cover cropping has been around for 2000 years! Scholars in the early 50’s (we are talking 50 AD) noted that sowing legumes in vineyards was beneficial to production. Cover cropping is the use of an unharvested crop that benefits the farm. Benefits are wide ranging, from controlling weeds to remediating soil structure; and from infiltrating water to adding organic matter. The different plants that can be used as cover crops are just as broad and what plant is chosen depends on the desired benefits. Possible cover crops are rye grass, barley, clover, buckwheat, fescue, even turnip!
Cover cropping can attract beneficial insects and add biodiversity to a farm which is always good news, but they also work in other ways to benefit environmental conservation.
Cover cropping protects our streams from nutrient loading, as crops with deep roots help increase infiltration of runoff. Water that might be contaminated by manure and excess nutrients during a rainstorm is more likely to sink into the ground in areas plants have deep roots to encourage infiltration. While planting trees and shrubs might not be ideal for farms that are trying to maximize sunshine a perennial cover crop could be the answer to help protect surface water quality. Deep rooted cover crops like clover also help with soil compaction, loosening soil and increasing infiltration to help with standing water issues in pastures.
Perennial cover crop (left year-round instead of turned into the soil as a “green manure” before planting) will suppress weeds so that less pesticides which can negatively impact our local streams are required.
Fall cover crops, if established early enough, are ideal for fall manure application. Nutrients are then taken up by the plants instead of being flushed away in the rain. Tightly stored in their little green leaves, the nutrients can be released in the spring when the plants are turned over; this process is called green manure or green mulch. Plants taking up these excess nutrients stores them for soil nutrients instead of ending up in local streams and eventually the ocean.
Legume cover crops like clover have the added bonus of fixing nitrogen in the soil. Nitrogen is essential for plants as it is a component of both chlorophyll and amino acids. Clover and other legumes have nodules on their roots that are great little houses for nitrogen fixing bacteria. The bacteria provides easy access to atmospheric nitrogen to the clover, the clover builds up nitrogen, when the clover dies and decomposes the now available nitrogen can be taken up by other plants.
There are three main clover varieties to choose from: white, red, and crimson. All great they can be better suited to different applications based on needs. Speak to a farm or garden expert for their advice.
Note: Alsike clover (Trifolium hybridum) is not recommended for pastures where horses graze. This introduced clover can cause health issues in horses and possibly other livestock.