Working with farmers - cover crops

Regenerative agriculture is a form of farming (producing food), which at the same time as producing crop also improves the environment.  This primarily means regenerating the soil; limiting soil disturbance, keeping the soil surface covered, keeping roots live in the soil, growing a diverse range of crops and bring grazing animals back to the land. 

Soil condition

A healthy soil has many microbiological components that help crops access nutrients and fight disease. Reducing the need for fertiliser and fungicides. A healthy soil is maintained by keeping the fungal hyphae intact e.g., not ploughing but using minimum tillage techniques that just lightly scratch the ground to sow crops.

Livestock

Many modern farms have specialised, and arable farms tend not to have livestock. By reintroducing livestock into a crop rotation by either grazing the cover crops or planting a field of grass, nutrients excreted from these animals can be used by the crop instead of using fertilizer. This also adds diversity to the rotation and grass is a great way to build up soil organic matter/soil carbon, so is good for capturing carbon and soil health.

Improving soil structure

Cover crops and green manure will add organic matter to soil. This improves soil structure and helps it absorb and keep in water. This means:

• ground conditions will improve, so farm operations are possible for longer
• you can reduce tillage and irrigation costs
• soil will retain more nutrients
• diversity of plant roots will scavenge for nutrients from the deeper soil layer and bring it up to the top where it’s most needed
• you’ll reduce the risk of soil erosion, as the flow of water into water bodies and watercourses is slowed
• you’ll increase beneficial microbes that will provide nutrients to the next crop
• the number of earthworms can increase in the soil, which helps prepare seedbeds and reduce disease organisms

Reducing soil erosion

You can reduce soil erosion and runoff using cover crops and green manure over bare ground in winter. This means:

• fields do not lose fertile topsoil and nutrients, like nitrogen and phosphorus
• water is cleaner, as less soil, pesticides and nutrients reach water bodies and watercourses
• you can reduce use of artificial fertiliser, as you’ll increase soil fertility
• you’ll stop nitrogen leaching, keeping nutrients in the soil for the following cash crop
• root system can break up compaction in soil which could help with infiltration
• more water is available for crops, as it infiltrates the soil more easily
• there’ll be a lower risk of flooding, as the flow of water into water bodies and watercourses is slowed

Reducing the use of pesticides and herbicides

Cover crops and green manure can reduce the use of pesticides and herbicides. They:

• create habitats that support natural predators of pests
• can grow fast and smother arable weeds, like black-grass
• improve soil structure, which prevents wet and compact soils favourable to weeds

Plant roots in the soil do a great job of making the soil more permeable to water. It is then available for crop use and doesn’t run off, taking soil, fertiliser and pesticides with it.  Plants also exude chemicals from their roots that help the soil keep its structure and encourage beneficial bacteria and fungi to grow (nematodes control). Diverse cover crop mixtures are also becoming increasingly popular among farmers, a wider range of cover crops enables a wider range of benefits to be introduced. Some roots with shallow fibrous roots to ‘condition’ the soil, deeper tap roots enable the harvesting of nutrients deeper in the soil, out of reach of crops, and legumes e.g. vetch fix nitrogen into the soil for subsequent crops to use.

Biodiversity is key in regenerative agriculture

The more plants you have, the more the different roots will help the soil, they all have different needs from the soil and help to keep pests and diseases in low numbers. Monoculture i.e. a field of one crop, is one of the practices of modern farming which inadvertently promote pests and diseases.

Companion cropping

Companion cropping is another way of helping the crop. E.g. Barley can be planted with peas. The peas grow up the barley so they don’t fall on the floor (lodging). They are harvested together and fed to cattle. The peas and barley work together to protect one another from pests as they are harder to see or find. Fungal spores that infect barley may land on a bean and therefore not cause disease, and act as a physical barrier to reduce disease transmission between plants.

Yield

Yield is traditionally how farmers measure their success. Regenerative farming reportedly leads to lower yields in the crop, however because less fertiliser and pesticides are used the costs to the farmer are less so they are more profitable. This fact alone is making farmers increasingly think about their chemical inputs and where they can cut back. Less chemical on the land means less chemical in the rivers and more insects for other wildlife to eat.