Kelly Tillage Logo

Green Manure Cover Crops: Nurturing your Farm’s Soil 


Think of your farm’s soil as a treasure chest, and green manure cover crops as the diligent guardians that watch over it, much like a hawk circling above, safeguarding its territory.

These cover crops are like the soil’s best friends, always there to enrich, protect, and make it ready for a fruitful harvest.

They’re the true farming heroes, working quietly but tirelessly with Kelly Tillage to ensure your soil stays healthy and your crops flourish. In this guide, we’ll explore the world of green manure cover crops and how they play an important role in nurturing your farm’s soil.

What are Green Manures? 

Green manure refers to a specific type of crop cultivated with the intention of being incorporated into the soil while still in its vibrant, green state. Typically, these crops are sown in vacant areas between primary crops. 

As they grow, they serve various valuable functions: their root systems act as ground cover, preserving soil structure and preventing erosion while retaining essential nutrients. They also inhibit weed growth and contribute to soil enrichment by fixing nitrogen.

Upon incorporation into the soil, the plant residues decompose and transform into a green manure mass that can either be tilled into the soil or utilised as mulch. This organic material, when spread over the soil’s surface, enhances its organic content and overall quality.

Green Leaf Manuring 

Green leaf manuring is the practice of trimming and collecting fresh leaves and twigs from various trees, herbs, and shrubs, and then applying them as natural fertilisers in other areas. 

Major sources of these organic fertilisers include leaves from forest trees, as well as herbs and shrubs that grow in field bunds, wastelands, and similar locations.

The Best Green Manure Crops 

Some commonly used cover crops include the following:


Grasses like annual ryegrass, oats, winter wheat, and winter rye are often used as green manure crops. They can help improve soil structure and prevent erosion while adding organic matter to the soil.


Buckwheat is a fast-growing summer cover crop that can suppress weeds, attract beneficial insects, and improve soil structure. 


Examples include vetch, clover, beans, and peas. These plants are known for their nitrogen-fixing abilities, which means they can capture atmospheric nitrogen and convert it into a form that can be used by other plants, thereby enriching the soil with nitrogen.

Green Manure Main Classes & Their Benefits 

There are three primary categories of green manure crops. Legumes contribute to soil fertility improvement by introducing nitrogen. Whereas Millet and Sorghum are known for their ability to generate significant amounts of organic matter. 

Benefits of Legumes 

The following are the advantages of Legumes: 

Nitrogen Fixation 

Using a legume as green manure is great because legumes can take nitrogen from the air and make it available for other crops. They work together with particular soil bacteria called rhizobia. 

These bacteria live on the roots of it and make little bumps called nodules. The bacteria get food from the legume, and in return, the legume gets nitrogen from the air turning it into a useful form.

When it is mixed into the soil, legume provides a natural source of nitrogen. This means we can use less artificial fertiliser for the next crop.

Prevents Soil Erosion

Anchoring Soil: Their roots hold the soil in place, preventing it from being carried away by wind or water.

Covering the Soil: The plants’ leaves and stems create a shield over the soil, shielding it from the impact of raindrops and the force of the wind, which reduces erosion.

Summer Fallowing Alternate 

Conventional summer fallow is like leaving a field with no protection, similar to how a house with no roof is exposed to the elements. It’s done to save water and control weeds, but it leaves the soil vulnerable to washing away, just like the rain can damage a house without a roof.

On the other hand, legume green manuring acts as a shield, similar to how an umbrella protects you from the rain. They also leave behind plant leftovers, which are like nourishing snacks for the soil.

This not only prevents the soil from washing away but it also makes the soil healthier.

Benefits of Millet & Sorghum 

Organic Matter Production

Millets and Sorghums are known for their ability to produce large amounts of organic matter. This organic matter, when incorporated into the soil, helps improve soil structure and water retention. It also contributes to the overall health of the soil by providing a source of carbon and nutrients.

Soil Erosion Control

The dense growth and root systems of millet and sorghum help prevent soil erosion. They reduce the risk of topsoil being washed away during heavy rains.

Weed Suppression

Both Millet and Sorghum are quick-growing crops that can smother and suppress weeds effectively. This reduces competition for nutrients, water, and sunlight with the main crop that follows, making it easier to maintain a weed-free field.

Drought Tolerance

Pearl millets are well-suited to areas with intermittent dry spells during planting. Their ability to withstand dry conditions makes them a reliable choice, especially in regions like Katherine where water availability can be a concern.

Green Manure Cover Crop Integration with Kelly

Searching for the ideal Kelly disc harrow for cover crop integration? The solution lies in the Model 3009. The following explanation will clarify why. 

Floating Wings Cylinders for Uneven Surfaces

The ability of this harrow to adapt to uneven field surfaces ensures that it can maintain consistent contact with the soil even in undulating terrain. This is beneficial when you’re planting cover crops, as it helps ensure uniform coverage of the green manure seeds or plants across the field.

Greater Ground Clearance on Contoured Terrain

The increased ground clearance allows it to navigate contoured terrain more effectively. This is useful when working with green manure, as it ensures that the equipment doesn’t get stuck or damaged in uneven areas of the field.

Reworked Drawbar for Manoeuvrability

Improved manoeuvrability due to a reworked drawbar is valuable when planting these crops, as it allows for tighter turns and better control, which can be especially important when navigating around obstacles or when dealing with smaller, irregularly shaped fields.

Greaseable Service Points and Wheel Hubs

These features make maintenance and servicing of the disc harrow easier. Regular maintenance is essential for keeping the equipment in good working condition when planting green manure cover crops. It ensures that the harrow operates efficiently and effectively.

High Strength Steel for Durability & Weight Reduction

The use of high-strength steel reduces the weight of this harrow while improving its durability. This can be advantageous when working with green manure cover crops as it reduces soil compaction and minimises the potential for damage to the field.

Green Manure Cover Crops Advantages  

Here’s why choosing manure cover crops over bare soil is the smarter option:

Green Manure a Nutritious Treat

Manuring is a common farm practice aimed at protecting main crops from the effects of heavy rainfall and strong winds, as well as enhancing the fertility of both the upper and lower soil layers by adding valuable substances.

Decomposed plant residues nourish the soil with organic matter and nitrogen. Additionally, as plants grow, they enrich the soil with essential nutrients such as phosphorus, iron, potassium, and calcium.

Prevents Soil Erosion and Leaching

These plants have root systems that help to aerate the soil, promoting improved oxygen and moisture retention. These roots work like tiny shovels in the soil, digging and loosening the soil on their own, without needing a big plough. 

Secondary tillage is still necessary for further soil refinement, much like the last strokes of a painter’s brush on a canvas.

Picture the Kelly Tillage Disc Harrows as skilled artisans for your farm. They work wonders, creating soil that’s as soft and smooth as the finest cotton, turning your land into a perfect farming canvas.

These cover crops have strong roots that hold the soil together, like a net, preventing it from being washed away. They also take up excess water and nutrients, keeping them in the soil and preventing leaching.

Best Weed Suppressant

These crops help suppress weeds through competition and allelopathy. Competition occurs when the cover crop shades the soil and competes with weeds for sunlight, water, and nutrients, making it difficult for weeds to grow.

Additionally, some green manure crops release chemicals that inhibit weed germination and growth, which is called allelopathy. 

Together, these mechanisms reduce weed growth, promoting a healthier and more productive field while also nurturing your farm’s soil.

Protection Against Pests and Diseases  

When a farmer sows these cover crops, you introduce a variety of plant species into the field. This diversity creates a more complex ecosystem where pests find it difficult to thrive. In simple terms, the presence of different plant species confuses and disrupts the life cycles of pests, making it harder for them to focus on a single crop. 

Moreover, these crops can release natural compounds or substances into the soil, some of which act as barriers to pests. 

This multifaceted approach of diversifying the farm environment helps reduce the pressure on specific crops from pests and diseases, contributing to a healthier and more sustainable farming system.

Attracting Helpful Insects

These cover crops are special because they have flowers that are very attractive to bees and bumblebees. These insects are natural pollinators. 

When they visit the flowers of these cover crops, they collect nectar and pollen for themselves. But as they move from flower to flower, some of the pollen from one flower sticks to their bodies.

Now, here’s the magic part: when bees and bumblebees go to other plants on the farm to collect nectar and pollen, some of that pollen from the first flower rubs off onto the female part of the new flower.

This is like a matchmaker bringing together the male and female parts of different flowers, allowing them to produce seeds.

And what do seeds lead to? They lead to the fruits and vegetables that we grow on the farm for food!

Green Manure Crops Disadvantages 

While the advantages of green manure are unquestionable, there are certain factors to take into account before implementing it.

High Moisture Consumption 

These crops require water for their growth. When planted in areas with limited moisture, they can deplete the available water resources. 

Consequently, this creates a need for additional irrigation to sustain the growth of the main cash crop.

This represents a notable disadvantage of using green manure cover crops, as the increased water requirements can be an added cost and resource demand for farmers, potentially impacting the overall economic and environmental sustainability of the farming system.

Limits Rotation 

Imagine your soil is like a tired person. After growing the main crop, it needs a break to regain its strength. If you plant a green manure crop right away, it’s like asking the tired person to keep working without a break. This can make the soil lose its nutrients and become less healthy over time.

Right Time To Sow Green Manure 

You can plant a green manure crop at any time of year if you have access to the right seeds, taking into consideration your local climate.

However, as a general guideline, it’s most beneficial to sow a green manure crop during either summer or winter. This allows for optimal incorporation into the soil the following autumn or spring.

Sandy Soils Green Manure 

If you’re feeling uncertain about which green manure suits your soil, here’s the answer to ease your confusion.

The most suitable green manure crops for sandy soils are those that can improve the soil’s capacity to retain water and enhance its nutrient content.

  • Millet 
  • Oats 
  • Wheat

Clay Soil Green Manure 

Following are the green manure for clay soil:

  • Clover 
  • Alfalfa
  • Winter Wheat 
  • Buck Wheat 
  • Lupins 

Final Words 

Green manure cover crops are like a farmer’s best-kept secret, giving your soil a makeover as refreshing as a cool glass of lemonade on a hot summer day! So, keep sowing those cover crops and watch your farm soil shine!