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Green manure

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**1. Application Methods:**
– Farmers blend plant discards into the soil or grow legumes for green manure.
– Harvesters gather green manure crops and mix them into the soil.
Green manure is added before or after planting cash crops.
– Planting schedules vary, as seen in rice farming.

**2. Functions and Benefits:**
– Green manures improve and protect soil quality.
– Leguminous green manures fix atmospheric nitrogen for plants.
Green manure releases 40-200 pounds of nitrogen per acre.
– Cover crops release nutrients for succeeding crops.
– Microbial activity enhances soil structure and nutrient availability.

**3. Nutrient Release and Management:**
– Bacteria break down green manure for plant nutrients.
– Warmth and moisture aid in the breakdown process.
Plant matter releases carbon dioxide and weak acids.
– Maintaining the correct carbon-to-nitrogen ratio is crucial.
– Legumes with rhizobium-rich root systems are preferred.

**4. Types of Crops Used:**
– Green manures are often planted in autumn or winter.
Alfalfa roots deeply to bring nutrients.
– Common green manure sources include beans, clover, and lupines.
– Green manures cover the ground before spring or summer sowing.
– Some green manure crops can be used for grazing.

**5. Limitations and Considerations:**
Green manure requires time, energy, and resources.
– Selection based on region and precipitation levels is crucial.
– Green manures reduce the need for additional fertilizers and pesticides.
– Erosion control is a factor in selecting cover crops.
Green manure incorporation reduces the need for supplemental products.

Green manure (Wikipedia)

In agriculture, a green manure is a crop specifically cultivated to be incorporated into the soil while still green. Typically, the green manure's biomass is incorporated with a plow or disk, as is often done with (brown) manure. The primary goal is to add organic matter to the soil for its benefits. Green manuring is often used with legume crops to add nitrogen to the soil for following crops, especially in organic farming, but is also used in conventional farming.

Green manure plants
image of different plants commonly used for green manure crops
A field of clover, a green manure crop
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