Green Manure – Definition & Detailed Explanation – Horticultural Terms Glossary

What is Green Manure?

Green manure refers to the practice of growing specific plants and crops with the intention of incorporating them into the soil to improve its fertility and structure. This process involves planting cover crops that are later tilled or mulched into the soil before they reach maturity. Green manure is a sustainable and environmentally friendly way to enhance soil health and productivity in horticulture.

How is Green Manure Used in Horticulture?

Green manure is used in horticulture as a natural method to replenish nutrients in the soil, suppress weeds, improve soil structure, and increase water retention. By planting cover crops specifically for the purpose of being turned back into the soil, gardeners and farmers can avoid the need for synthetic fertilizers and chemical pesticides. Green manure is often used in organic farming practices to promote soil health and sustainability.

What are the Benefits of Using Green Manure?

There are numerous benefits to using green manure in horticulture. Some of the key advantages include:

1. Soil Fertility: Green manure crops add organic matter to the soil, which helps improve nutrient levels and promotes healthy microbial activity.

2. Weed Suppression: Cover crops can outcompete weeds for resources, reducing the need for herbicides and manual weeding.

3. Soil Structure: Green manure helps improve soil structure by increasing soil porosity, aeration, and water infiltration.

4. Water Retention: Cover crops can help prevent soil erosion and improve water retention, reducing the risk of drought stress in plants.

5. Pest Control: Some green manure crops have natural pest-repelling properties, reducing the need for chemical insecticides.

What Types of Plants are Used as Green Manure?

A wide variety of plants can be used as green manure, depending on the specific goals of the gardener or farmer. Common green manure crops include legumes such as clover, vetch, and alfalfa, which are known for their ability to fix nitrogen in the soil. Other popular cover crops include grasses like rye and oats, as well as brassicas such as mustard and radish. Each type of plant offers unique benefits to the soil, making it important to choose the right green manure crop for the desired outcome.

How is Green Manure Incorporated into the Soil?

Green manure is typically incorporated into the soil through tillage or mulching. Before the cover crops reach maturity, they are cut down and either tilled into the soil using a tractor or garden tiller, or mulched with a mower or scythe. The green manure plants decompose in the soil, releasing nutrients and organic matter that benefit soil health. The timing of incorporation is crucial, as it should be done before the cover crops start to compete with cash crops for resources.

What are Some Common Green Manure Crops?

Some common green manure crops include:

1. Clover: A leguminous plant that fixes nitrogen in the soil and improves soil fertility.

2. Rye: A grass cover crop that helps suppress weeds and improve soil structure.

3. Mustard: A brassica crop that has natural pest-repelling properties and adds organic matter to the soil.

4. Vetch: Another leguminous plant that fixes nitrogen and improves soil health.

5. Oats: A grass cover crop that helps prevent soil erosion and increase water retention.

By incorporating green manure crops into their horticultural practices, gardeners and farmers can improve soil fertility, suppress weeds, and promote sustainable agriculture. This natural method of soil enrichment offers numerous benefits for both the environment and crop production.