Effect of short-term perennial leys on life cycle environmental performance of cropping systems: An assessment based on data from a long-term field experiment

Modern agriculture’s dependence on the intensive use of inputs, such as chemical fertiliser and pesticides, leads to high environmental impacts and, possibly, vulnerability in food security, since most these inputs are imported from other countries. This calls for more sustainable resilient agricultural practices. Diversification crop rotations, e.g. by including perennial leys, enhances provision ecosystem services, leading healthier crops increased yields. Perennial also increase soil organic carbon (SOC) stocks, which is interesting a global warming mitigation perspective. In addition, legume-rich leys can utilise atmospheric nitrogen (N) through symbiotic association with N2-fixing bacteria. However, few studies have evaluated effects short-term rotation cropping system performance over long periods under different conditions. this study, we used data three sites long-term experiment Sweden (initiated 1960 s), combination Life Cycle Assessment methodology, assess yield effect ley rotations. Two N regimes (High, Low) six-year consisting either i) two-year mixed grass-legume ley, ii) pure grass or iii) annual without were compared. Environmental (climate impact, energy resource depletion, eutrophication potential) combinations quantified per kg harvested (expressed cereal units, CU) hectare. The lowest at all sites, was found Low regime. On average, resulted 329 g lower GHG emissions CU than N, primarily due input fertiliser, reduced impact production N2O emissions. Comparison mean SOC change study period revealed stocks rotations especially ley. Therefore, containing legume species, be useful tool meeting policy targets reducing agriculture, purchased commodities. despite potential benefits rotational market demand produced biomass may insufficient. Hence, incentives necessary promote large-scale adoption, example, bioenergy feed.