Oats and peas are plants used as cover crops for weed control as well as cash crops on their own. The National Sustainable Agriculture Research and Education website says that "cover crops suppress weeds and reduce damage by diseases, insects and nematodes." Oats and peas provide leaf canopy that blocks light, alters the frequency of light waves and changes soil temperature surface to prevent weed growth.
Weeds are plants growing in areas where they are not wanted. They compete with vegetables and fruit trees for available sunlight, nutrients and water. They can reduce food production, quality and yield, as well as make harvest difficult. Weeds may also provide cover for unwanted harmful insects and small animals. There are cultural, mechanical and chemical methods for weed control.
Oats and peas are used as commercial crops, green manure cover crops and weed suppression crops. Weeds are crowded out by their fast growth as both compete for sunlight and water supply. They are seeded in late summer or fall to establish good root and crown growth over wintertime, providing biomass for soil improvement. They provide erosion control and weed suppression where soil would otherwise lie fallow.
Legume crops such as peas improve soil as well as suppress weeds. They are cut down and allowed to decompose on the ground as mulch, adding biomass. Soil improves gradually with the constant addition of decaying organic matter. Cover crops are sometimes grown for short periods between cash crops or allowed to mature and harvested. Peas absorb nitrogen from the air, which becomes usable in soil.
Oats are a cool season annual cereal crop used for weed suppression. They are an inexpensive crop to use for fall planting and quick growth. They can be planted with peas, crown vetch, clover or other legumes and small grains to serve as a green manure and weed suppressor. Oats thrive in cool, moist conditions on well-drained soil.their fibrous root system holds soil during cool weather gaps in crop rotation.
Peas are a summer and winter annual legume used as a weed suppressor and to fix nitrogen into soil for subsequent crops. They are grown with wheat, barley, triticale or rye for vertical support. Peas thrive in moist conditions and cool weather. They are "high N-fixers," according to the Sustainable Agriculture Research and Education website, that contribute to short-term soil conditioning.