Green manure refers to crops that are grown and then incorporated into the soil to improve soil fertility, structure, and organic matter content. There are several types of green manure crops, each with its own benefits and characteristics. Here are some common types:
- Legumes: Leguminous plants have the ability to fix atmospheric nitrogen through symbiotic relationships with nitrogen-fixing bacteria in their root nodules. When these plants are incorporated into the soil, they release nitrogen, enriching it for subsequent crops. Common leguminous green manure crops include:
- Grasses and Cereals: Grasses and cereals are valued for their ability to produce large amounts of biomass, which helps in improving soil structure and organic matter content. They also scavenge nutrients from deeper soil layers and make them available to subsequent crops when incorporated. Common grass and cereal green manure crops include:
- Brassicas: Brassica species are known for their deep root systems that help break up compacted soil and scavenge nutrients from lower soil layers. They also contain compounds that can suppress certain soil-borne pests and diseases. Common brassica green manure crops include:
- Lupins: Lupins are leguminous plants that can fix atmospheric nitrogen and improve soil fertility. They are well-suited for acidic soils and contribute organic matter when incorporated into the soil.
- Clover Mixtures: Some green manure mixtures combine different species, such as a combination of legumes and grasses or legumes and brassicas. These mixtures provide a diverse array of benefits, including nitrogen fixation, soil structure improvement, and nutrient scavenging.
- Cover Crops: While not all cover crops are green manures, many serve a dual purpose of providing soil cover and organic matter when incorporated. Examples include various clovers, oats, and annual ryegrass.
TYPES OF GREEN MANURE