Cover crops are a cornerstone of every sustainable agriculture strategy. They provide a whole host of benefits with hardly any drawbacks, across several different climates. If used correctly, they can improve soil water retention capacity, biodiversity, yields, and more.
Cover crops should be viewed as a long-term investment in improved soil health and farm management. They can begin to pay for themselves in the first year of use, or it may take a few years for them to lead to a net positive return.
What is a Cover Crop?
A cover crop is a plant that is grown mainly to benefit the soil rather than to be harvested for profit. Cover crops are commonly used to suppress weeds, manage soil erosion, help build and improve soil fertility and quality, control diseases and pests, and promote biodiversity.
There are several plants that can be used as cover crops, but most typical are grasses or legumes such as clover. The most common way to implement cover crops is by planting them in the off-season, prior to planting the primary cash crop. A cover crop prepares the land and soil for the incoming cash crop, so the farmer can have a better chance of a high-yielding, profitable season.
Some good examples of cover crops include:
- Rye: Also known as winter rye or cereal rye, this cover crop is often used to loosen compact soil and suppress weeds.
- Buckwheat: Fast-growing buckwheat helps prevent erosion and suppress weeds.
- Clover: Clover is great for fixing nitrogen in the soil and adding fertility.
- Sorghum: This hybrid cover crop grows quickly, adds biomass, and suppresses weeds.
- Hairy vetch: Vetch adds nitrogen and is a good overwinter crop for northern climates.
What is Cover Cropping?
Cover cropping is the process of using cover crops to benefit the soil prior to planting the main cash crop. The cover crop is planted in the off-season, and then is allowed to grow out. Once it is fully grown, the conventional farmer will typically mow it down and allow it to dry out, before tilling it into the soil.
Organic farmers, on the other hand, take a different approach - particularly in drought-stricken areas. In low-moisture conditions, it makes more sense to leave the harvested cover crop on the ground as a mulch layer. This slows the rate of evaporation of water from the soil, and also means farmers don't have to resort to tilling the soil.
The Benefits of Cover Cropping in Agriculture
Cover cropping is one of the closest things agriculture has to a silver bullet in terms of best practices. In other words, cover crops carry a wide array of benefits with no serious drawbacks or obstacles to implementation. Some benefits of cover crops include:
- Improved biodiversity: Decomposing cover crops help feed soil life and contribute to stable soil organic matter, which improves nutrient cycling, soil structure, and builds a diverse microbiome in the soil. Additionally, they improve biodiversity above ground by increasing the variety of species in a given area. For example, if there are more varied insects that feed on the varied vegetation, it can bring more birds, and so on.
- Reduced/Eliminated disease cycles: Increased soil biodiversity reduces the amount of bacterial and fungal diseases in the soil. If you have a soil that is infested, you can plant a cover crop in that area as a means to eradicate the disease.
- Increased soil nutrient density: Cover crops provide nutrients to the soil, similarly to how compost does.
- Stabilised soil particles: Cover crops can help join soil particles into stable aggregates which in turn help soils better absorb intense rain, resist erosion, and improve water holding capacity in drier conditions.
- Reduced runoff: Cover crop can reduce the amount of water that drains off a field, protecting waterways and downstream ecosystems from toxicity due to high nutrient concentrations.
- Reduced soil erosion: Increased cover crop planting means more roots in the soil. Every root creates pores in the soil, allowing water to filter deeper into the ground. This results in conservation of water and prevention of soil erosion.
- Improved planting conditions: Cover crops take up excess water, which can help dry out wet fields before planting.
- Reduced carbon footprint: Cover crop can reduce water pollution risks, and also remove carbon dioxide from the atmosphere, sequestering it into the soil instead. They help the environment and literally reduce a farm’s carbon footprint.
- Boosted economic benefits: Cover crops can increase primary crop yields, reduce machinery costs, out-compete weeds, break disease and insect cycles, host beneficial organisms, attract pollinators, scavenge nutrients, and supply forage.
Cover Crops For a Sustainable Agriculture
Cover crops are a key part of sustainable agriculture. They bring immense benefit to soil health, soil surface and organic matter, which is the whole aim of regenerative agricultural practices. Though it may take some time to see initial returns on investment, your pockets, fields, soils, and future generations will thank you for it one hundred-fold.