Preserving the sustainability of field crop systems: overview of 50 years of trials in Changins

Preserving soil fertility is a major challenge for farms without livestock specialised in field crops. Several decades ago, several trials were set up at the Agroscope experimental station in Changins to study the long-term effects of different cultural practices on soil fertility and crop yields. This article summarises the main results obtained in these trials. In the conditions at Changins, organic amendments have been useful for stabilising soil organic carbon content, and only high manure inputs have enabled its significant increase. To preserve soil fertility, farm manures are difficult to replace. Without regular organic amendments, reducing tillage is generally not enough to maintain soil organic carbon content, but can slow its decrease. By combining a diversified crop rotation, reduced tillage and regular organic inputs, it is possible to maintain soil fertility and crop yields on the long term. Long-term trials are indispensable for understanding and simulating the long-term impact of different cultural practices on the sustainability of field crop systems.