Management methods that decrease requirement for agricultural chemicals are needed
to reduce adverse environmental impacts. Moreover, they can play an important role in
atmospheric C02 emission and fixation. We propose green manure legumes to reduce
erosion, soil compaction and nitrate pollution, to improve biodiversity, soil carbon sink
and fertility, to save fossil fuels and to increase yield and the nutritional value of food
products. The research was carried out near Mirandela, Northeast Portugal, on a 15-
year commercial olive orchard (Olea europaea L. cv. Cobrançosa), grown under
rainfed conditions
