Modern agroforestry systems have the potential to combine productive agriculture with increased environmental benefits. Because these systems have only recently been tested by a few farmers in Switzerland, there is hardly any data available on the environmental impacts of modern agroforestry systems. In this study, we examined the changes in soil organic matter (SOM) stocks in a seven-year old agroforestry system in central Switzerland. Our results show that after just seven years, a substantial accumulation of SOM (+18 %) can be observed in the tree row compared to in the cultivated land. Surprisingly, the accumulation of SOM was not restricted to the topsoil, but was also detected up to a soil depth of 60 cm. An initial estimate of the annual SOM accumulation in the agroforestry plot investigated stands at 0,86 t of carbon per hectare and year and 91 kg nitrogen per hectare and year for a soil depth of 0–60 cm. The magnitude of this initial estimate shows that further research into the SOM dynamics of agroforestry systems is of great importance from the perspective of soil, climate and water protection.
Increased SOM stocks in a seven-year-old agroforestry system in central Switzerland