Home Gardening Green Manure Definition and Examples

Green Manure Definition and Examples – GIY Plants

Farmer on his tractor in the field turning green manure into the soil.

Green manure is used in agriculture to describe specific crops grown and incorporated into the soil to improve its structure and fertility. These crops are often leguminous, meaning they can fix nitrogen from the air into the soil. Green manure serves multiple purposes: soil erosion control, weed suppression, and nutrient conservation.

Types of Green Manure Crops

Red clover growing, a type of green manure used to increase soil fertility.

Legume Green Manures

Legume green manures like clover, vetch, and other leguminous crops are excellent at fixing nitrogen from the atmosphere. These crops are often used in organic farming to enhance soil fertility.

Non-Legume Green Manures

Non-legume green manures include plants like rye, buckwheat, and brassica. While they don’t fix nitrogen, they are excellent for adding organic matter to the soil.

Advantages of Using Green Manure

Soil Fertility

One of the primary advantages of green manure is its ability to improve soil fertility. The decomposing plant matter adds essential nutrients to the soil, making it more fertile for the next crop.

Weed Suppression

Green manure crops can also act as smother crops, effectively suppressing the growth of weeds. This is particularly beneficial in organic farming, where chemical weed killers are not used.

Erosion Control

The root systems of green manure crops help in controlling soil erosion. They hold the soil together, preventing it from being washed away by rainwater.

Disadvantages to Consider

Time and Effort

Growing green manure crops requires time and effort. It’s crucial to factor this into your crop rotation plans.

Pests and Diseases

Some green manure crops can attract pests and diseases. It’s essential to choose crops resistant to the problems in your area.

How to Use Green Manure

Sowing the Seeds

To use green manure, start by sowing the seeds of your chosen crop. The sowing process is similar to any other crop and depends on your chosen plant.

Growing the Crop

Allow the green manure crop to grow until it’s still green, but before it starts to flower. This is the optimal time for it to be incorporated into the soil.

Incorporating into the Soil

Once the crop has grown to the desired stage, it’s time to till it into the soil. This process allows the green manure to decompose and release its nutrients.

Examples of Green Manure Crops


Field of clover planted as green manure.

Clover is a popular legume green manure. It’s excellent for fixing nitrogen and improving soil structure.


Cut rye laying on ground being used as a green manure.

Rye is a non-legume green manure that adds organic matter to the soil. It’s also suitable for controlling erosion.


Field of flowering buckwheat growing as a green manure.

Buckwheat is fast-growing and excellent for suppressing weeds. It’s also suitable for breaking the life cycle of weed plants.

Green Manure in Sustainable Agriculture

In the context of sustainable agriculture, green manure plays a pivotal role. It reduces the need for synthetic fertilizers and promotes a more natural cycle of nutrient replenishment.

Frequently Asked Questions

What is green manure?

Green manure refers to the practice of growing certain types of crops, known as cover crops, and then incorporating them into the soil to improve its fertility.

What is a cover crop?

A cover crop is grown primarily to protect and improve the soil rather than for harvest. It is typically grown between main crops or during fallow periods.

How does green manure add nitrogen to the soil?

Certain cover crops, especially leguminous ones like clover or vetch, have the ability to fix atmospheric nitrogen into a form that plants can utilize. When these cover crops are incorporated into the soil, they release nitrogen, increasing soil fertility.

How do you sow green manure crops?

Green manure crops are typically sown by broadcasting the seeds directly on the soil surface and lightly raking them in. Following the recommended planting instructions for each specific cover crop is essential.

What nutrients do green manure crops provide?

Different green manure crops provide varying levels of nutrients. Still, they generally contribute nitrogen, potassium, phosphorus, and several micronutrients to the soil.

What are the advantages and disadvantages of using green manure?

The advantages of using green manure include improved soil fertility, reduced erosion, weed suppression, and increased organic matter. However, there can be challenges with timing the incorporation of cover crops and potential competition with main crops.

Can green manure be used as mulch?

Yes, green manure can be used as a mulch. When cover crops are grown densely, they can be cut and laid on the soil surface to act as mulch, helping conserve moisture and suppressing weed growth.

What are some examples of green manure crops?

Some green manure crops include ryegrass, winter rye, clover, vetch, buckwheat, and mustard. These crops are known for their ability to improve soil fertility and structure.

How do you plant green manure?

To plant green manure, you must remove any weeds or debris to prepare the soil. Then, sow the chosen cover crop seeds according to the recommended spacing and depth. Water the area well and ensure the cover crop receives adequate sunlight.

How do I choose green manure crops for my specific needs?

When choosing green manure crops, consider your soil’s nutrient needs, climate conditions, and the benefits you want. Certain crops, like legumes, are excellent nitrogen fixers, while others excel at weed suppression or adding organic matter.


Understanding the role and benefits of green manure can significantly impact your farming success. Whether you’re into organic farming or looking for ways to improve soil fertility, green manure is an invaluable tool in your agricultural arsenal. Choose wisely, and your soil will thank you for it.

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