Published 22.02.2023
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Enhance biodiversity and gain robust systems
Agrobiodiversity is the term for the biodiversity found in agriculture. It encom-passes all forms of life, from plant varieties and animal breeds to microorganisms, pests and pollinators.
By Maja Eline Petersen
A high level of biodiversity on the farm – both in the form of well-preserved natural areas and variation in farming practices, such as crop choice, improves stability and provides more ecosystem ser-vices, such as natural pest control, pollination, and increased soil fertility. The diversity of species that can benefit cultivation is called functional biodiversity. In other words, it is biodiversity that is useful to farmers.
In addition to a beneficial function for production, organic farming with high agrobiodiversity can support the species that live in and depend on farmland food sources and habitats. This, together with a holistic management of connected natural areas, is an important contribution to solving the biodiversity crisis.
Different kinds of biodiversity
- Functional biodiversity: The diversity of living organisms that benefit the farmer’s production.
- Agrobiodiversity: The diversity of living organisms in the agricultural system.
- Biodiversity: The diversity of all living organisms.
Examples of beneficial organisms
- Micro- and macro-organisms that decompose soil organic matter, thus improving soil structure and the ability for plant growth.
- Pollinators that increase the quality and yield of crops.
Natural enemies that eat crop pests.
Strip cropping creates a beneficial mosaic
In a strip cropping system, different crops are grown in alternating strips in the field. The strips are wide enough to be cultivated with machinery independently of the other crops but narrow enough to have an ecological interaction between the different crops in the strips.
By growing several different crops in one area, you can create a beneficial mosaic of habitats and resources that support a rich insect life. Many of the insects associated with open land need multiple types of plant cover. In large fields with a single crop, insects are typically found along the edge of the field, where the crop is adjacent to another field or hedgerow. If the field is divided into several strips with different crops, you will have far more edges that can provide different resources for the insects. This encourages insect life.
If designed accordingly, strip cropping can ensure that there are places with green plant cover all year round, providing different food sources, hiding-, and overwintering places throughout the year for the beneficial insects. It creates places to migrate to when cultivation disrupts them.
Agroforestry
Agroforestry provides a greater range and diversity of food, shelter, habitats, and breeding sites for the benefit of mammals, birds and insects.
The species composition of trees in agroforestry has an impact on diversity, which will typically increase in line with an increased diversity of tree species. The size of the agroforestry system mat-ters, but even quite small areas of tree planting are considered to have a positive impact. The distance between trees in agroforestry and other biotopes and the connectedness of them in the form of dispersal corridors affects biodiversity and the species’ ability to move through the landscape.
The improved agrobiodiversity created by agroforestry has the potential to increase natural pest prevention and control and provide better pollination of crops by wild bees. Finally, agroforestry creates undisturbed soil in the field with food sources essential for the diversity and density of soil organisms that create fertile soil.
The primary cause of biodiversity loss in farmland is intensification of agriculture, where a focus on efficiency has resulted in a simplification of ecosystems. Mixed farms have be-come specialised, fields have become larger, hedgerows and trees have been removed and small biotopes reduced. Combine this with frequent spraying and fertilization, and we are left with an agricultural system that can’t provide enough food for the upper layers of the food web. If we want to reverse the decline of animals in our farmland, we need to create better living conditions for them.