Many good reasons to sow a cover crop
Published 12:00 am Friday, October 18, 2013
SALISBURY — Cover crops sometimes confuse homeowners and growers alike, but using cover crops can help improve soil compaction, nutrients, moisture, weed suppression and numerous other benefits.
With all of those benefits you wonder why everyone is not growing them. For most, the main reason is they have never heard of cover crops. Extension agents typically put cover crops into two categories: winter and summer. This is about winter cover crops.
Within the winter cover crops, there are two types, legumes and non-legumes. Legumes are plants that can fixate nitrogen, meaning that they will create their own and will help provide nitrogen to other plants, which can reduce fertilizer usage. Some legumes that grow well in North Carolina are hairy vetch, crimson clover and Austrian winter pea. Legumes should be planted around mid- October.
Non-legumes would be cereal rye, barley, wheat, annual ryegrass and mustards. There are also some interesting cover crops, such as the daikon radish. Daikon radishes are edible and used in numerous Asian cuisines but the truly unique part of the daikon radish is that it helps alleviate soil compaction. This large radish will grow through the soil and if left alone will rot, creating a cavity that will provide an area for air and water saturation. The decomposing radish will also provide nutrients to the soil and future crops. The smell of the rotting radishes is not the best but it is definitely a great cover crop to try.
Another cover crop being used is rapeseed. This plant is showing great promise as a cover crop and root knot nematode suppressor. Typically, the Piedmont of North Carolina does not see as much problems with root knot nematodes but they do sometimes occur. They occur much more frequently in sandy soils — that’s another reason why it is important to know where you buy your soil from because parasitic nematodes could also be present.
Most homeowners shy away from cover crops because they are unsure how to use them or believe they are only good for large growers; this is simply untrue. Small growers can use cover crops as much as larger growers. The key is to select the cover crops suited to your own needs. If you use compost and manure, incorporate the compost and manure, then broadcast the cover crop seed. Usually we make a recommendation to use both legumes and non-legumes together. A popular combination is hairy vetch and cereal rye. Using them both will help increase nutrients and the non-legume will help with weed suppression.
Another key part is to determine if you will use the cover crop as a green manure by tilling in the growing cover crop, or by killing the cover crop before maturity and allowing the decomposing cover crop to become a mulch, weed suppressor and slow nutrient releasing crop. The main item to consider is to explore your options, but always do your research. Some cover crops, if left unsupervised, are very aggressive and can get out of hand. If you would like more information on cover crops visit: http://growingsmallfarms.ces.ncsu.edu/growingsmallfarms-wintercrops/ or http://pender.ces.ncsu.edu/2012/08/improve-your-garden-soil-with-cover-crops/
Contact Danelle Cutting, Extension agent, at 704-216-8970.