Weed control in a pesticide‐free farming system with mineral fertilisers

Abstract

Negative impacts of pesticides on the environment and human health, the risk of pesticide residues in the food chain, and the problems with herbicide‐resistant weed biotypes support the need for alternative cropping systems. The objective of this study was to investigate weed populations, weed management and crop yield in a pesticide‐free cropping system with the use of mineral fertilisers. Conventional‐, organic‐ and mineral‐ecological cropping systems (MECS) with 6‐year crop rotations including winter wheat, maize, winter triticale or winter rye, soyabean or spring pea, and spring barley were established in a randomised complete strip plot design with four repetitions. Experiments were conducted at four locations in Germany. Preventive and sensor‐guided mechanical weed management strategies were applied in all crops in the organic system and in MECS. Herbicide were applied in the conventional farming system. Weed densities, weed species composition, weed control efficacy (WCE) and crop yield were analysed over 2 years in 2020 and 2021. Conventional farming had the highest WCE and 1–7 weeds m−2 (2.7% weed coverage) after herbicide application. In the organic cropping system and MECS, up to 27 weeds m−2 were counted after camera‐guided weed hoeing. Weed coverage in MECS (9.7%) was higher than in the organic cropping system with 7.7%. Crop yield in MECS was equal to the conventional farming system and 20% higher yield than in the organic farming system. MECS represents a promising new and productive cropping practice if an effective integrated weed management strategy is applied.