No-till grain legume production in organic farming : constraints, possibilities and potential agronomic practice

Sammanfattning: Today’s agriculture is often specialised, and relies on pesticides, synthetic fertiliser and tillage. Tillage, especially ploughing, has shown to have a negative impact on climate, soil health and -biodiversity. An alternative is no-tillage, a practice that leaves the soil almost undisturbed except for minimal impact during sowing. Implementing no-tillage into organic agriculture has potential to make it more sustainable. However, it is a challenge since tillage is the main method of weed control in organic agriculture, especially in row crops with low competitiveness against weeds like grain legumes. Cultivation of grain legumes generates significantly less greenhouse gas emissions compared to animal products and are beneficial for cropping systems. The aim of this study is to explore agronomic options available for cultivating grain legumes using no-tillage in organic agriculture: cover crop mulch, crop residue retention and intercropping. This is done by reviewing literature and interviewing a crop production advisor. The transferability of the reviewed research results to Swedish pedoclimatic conditions is discussed. The results show that no-tillage is uncommon in organic farming in northern climates due to the lack of efficient alternative weed control methods. Using mulch is a common method of weed control in organic no-tillage. However, in Sweden the growing period is too short to achieve the amount of biomass needed for weed suppression through mulching. Intercropping has shown to be beneficial for controlling weeds and could be feasible in Sweden. More research in this area is needed to successfully implement no-tillage into organic grain legume farming in Sweden.