Mitigation effects of agroforestry on crop environmental stress

在泰国Kohn Kaen大学的农田和京都大学的塑料房中研究了农林业对作物环境胁迫的缓解作用。在前者中，在2003-04年旱季在芒果树的小巷之间种植玉米植物，在2004-05年旱季种植花生植物。很可能在两个季节都发生了树木的水力提升。然而，它对玉米植株的影响没有观察到，可能是因为作物的高需水量。对于花生植物，有人建议，白天树木和作物植物之间的水分竞争被夜间提升的水分所缓解。在塑料大棚中的试验中，在分根器的一个隔室中种植一棵红果树和高地，而在另一个隔室中只种植高地。晴天时北方稻株的光合作用约为南方的20%，但仍能存活，而南方稻株在土壤干燥时会萎蔫。很可能在相关的一侧发生了水力提升，转移到表层根系的水被释放到土壤中，使该隔室中树下的水稻植株能够保持活力。研究发现，农林复合系统可以缓解农作物的环境胁迫。

Mitigation effects of agroforestry on crop environmental stress were examined at fields of Kohn Kaen University in Thailand and in a plastic house in Kyoto University. In the former, maize plants were planted between alleys of mango trees in 2003-04 dry season, and groundnut plants in 2004-05 dry season. It was likely that hydraulic lift by the trees occurred in both seasons. However, its effect on the maize plants was not observed probably because of high water demand of the crops. For groundnut plants, it was suggested that competition for water between the trees and the crop plants in daytime was mitigated by water lifted at night. In the experiment in the plastic house, a markhamia tree and upland rice plants were planted in one compartment of a split-root apparatus, with only upland rice plants planted in other compartment. Photosynthesis of the rice plants in northern side on clear days was about 20% of that in the south, but they remained viable, though rice plants in the south side wilted when soil was dried. It was likely that hydraulic lift occurred in the associated side and that water that had been transferred to the surface roots was released into the soil, enabling the rice plants below the tree in this compartment to remain viable. In this study, it was found that environmental stress of crops would be mitigated by agroforestry system.