Project description
Many agricultural soils are increasingly losing humus and thus their ability to store water. In times of more frequent dry spells, this becomes a major risk to stable yields and long-term soil fertility. In oat cultivation in particular, water shortages can quickly lead to quality losses. At the same time, agriculture is expected to promote greater biodiversity while remaining economically viable.
Although flower strips offer ecological advantages, they reduce the amount of land available for cultivation and incur additional costs. There is therefore a lack of practical methods that simultaneously improve soil, water balance and biodiversity without farms having to bear economic disadvantages or investment hurdles.
The project is investigating how diverse undersown crops in oat cultivation can help to make soils more water-rich, higher-yielding and ecologically valuable. The idea is that while the oats are growing, the undersown crops develop their own root system, bringing more carbon into the soil and strengthening the microbial community. After the oats are harvested, the undersown crops bloom, serving as a food source for pollinating insects. In addition, the plant mulch provides valuable protection against evaporation for the soil, especially in autumn and winter. As a result, the subsequent crop, usually wheat, starts the growing season with higher soil water content and has better access to water resources in the subsoil.
Extensive field trials are being conducted to investigate humus formation, nitrogen balance, water availability, root development, yields and the biodiversity of flower-visiting and soil-dwelling insects. The results are incorporated into an easy-to-implement field protocol that provides farmers with specific recommendations for the selection and management of undersown crops.
A key advantage is that the method does not require any additional machinery – the undersown crops can be sown using standard farm equipment. This means that the process can be established without investment and makes oat cultivation more attractive overall. At the same time, biodiversity, humus balance and climate resilience benefit.
Through broad-based public relations work, advisory services and follow-up cooperation, the knowledge is being put into practice on a permanent basis, even beyond Schleswig-Holstein. Seed suppliers, agricultural advisory offices and farms are thus provided with a sound basis for establishing undersown mixtures for oat cultivation as a standard practice in the long term.