Improvement of the soil properties, nutrients, and carbon stocks in different cereal–legume agroforestry systems

In the present study, the soil properties of the three agroforestry systems including almond intercropped with barley, wheat, and clover rotated yearly with each other were compared at different distances from almond rows with their treeless control systems in the semiarid Saman area, Iran in 2016. Result showed that after eight years, organic carbon contents of the soil were influenced in the agroforestry systems mainly near the trees. Higher soil carbon stocks (56 t/ha) were observed near the almond trees at the distance of 0.5 m. The highest field capacity (28%) and soil organic carbon (1.82%) were also observed at the same distance, especially for the barley. Although there was no significant difference in the nitrogen amount between the systems, the highest amount of phosphorus was observed in the agroforestry plots with barley and clover at 2.5 m far from the trees. Intercropping with almond also increased the available potassium at both distances from the trees. Finally, it can be said that the agroforestry leads to sequestration of higher amounts of carbon in the soil and offers further moisture and more amounts of phosphorus and potassium for the next crop promising a more sustainable agriculture in the next seasons.