Double Cropping, Plant-Based Fertilization And Winter Plant Cover In Vegetable Production For Sustainable Intensification – A System’S Approach

Summary

The global agenda asks for high and efficient food production in a sustainable way. A major part of the solution is a significant increase in vegetable consumption, which asks for an implementation of sustainable intensification in organic farming production of open-field vegetables. The aim of this study was to advance the design of cropping systems and their nitrogen management to achieve high yielding systems, while limiting nitrate leaching. A 5-year crop rotation trial was designed, including double cropping, plant-based fertilisers, catch crops, green manures and plough-free controlled traffic farming. The system was compared to a more standard organic crop rotation, fertilised by liquid manure. Crop yields, root growth, plant and soil nitrogen pools, soil microbial activity and nitrate leaching potential were studied in two years. Results showed that yields calculated per area were maintained for each crop, and increased for the season in the double-cropped system for at least two out of four fields of the rotation. Effects on soil nitrogen availability and leaching potential were ambiguous. Soil microbial activity, measured as potential nitrogen mineralisation and enzymatic activity, increased by more than 15% in the double-cropped compared to the standard system in the crop rotation. In conclusion, yields and soil fertility increased in the double-cropped system fertilised by plant-based sources and managed by plough-free controlled traffic farming. However, the high soil fertility asks for an increased focus on winter plant cover to avoid high leaching losses and to align to the principles of sustainable intensification.