根障对农田林网内土壤水分和小麦产量的影响

在农田林网内四侧林带附近分别采用不同类型的根障,阻断树木根系侵入农田,减少树木与作物间的水肥竞争。在林带与小麦竞争激烈的小麦灌浆期测定灌溉后10 d、15 d和20 d的农田表层20 cm的土壤体积含水量,并结合小麦的产量得到根障对农田防护林系统的影响。结果表明,根障对四侧林带附近土壤含水量的影响不同。灌溉后20 d内林网土壤体积含水量整体分布:林网南侧>林网东侧>林网西侧>林网北侧,根障区>无根障区。根障能够提高林带附近1.0 H内土壤体积含水量0.78%～2.33%,增加小麦产量1.05%～12.06%,使减产区由1.0 H减少到0.5 H范围内。根障仅能减小胁地影响,但不能完全消除竞争。结合土壤水分和小麦产量得出根障离林带越近效果越好。

Effect of root barrier on soil moisture and wheat yield within farmland shelternet

Root barrier is one of the effective ways to reduce the bad effect of shelterbelt at present.In this experiment,different kinds of root barrier was applied on four sides of shelterbelt within farmland shelternet,aiming at blocking-up tree root which invaded into farmland and decreasing the soil moisture and nutrition competition between trees and crops.Soil volumetric water content was determined after irrigation for 10 d,15 d and 20 d at wheat filling stage when the competition was serious between shelterbelt and wheat,and the root barrier effect on farmland shelterbelt system was evaluated with regard to soil volumetric water content and wheat yield.The result indicated that the root barrier effect was different on four sides of shelterbelt within shelternet.The distribution order of soil volumetric water content within shelternet after irrigation for 20 days was south,east,west and north,the soil water content was higher in root barrier zones than non root barrier zones.Root barrier increased 0.78%~2.33% soil water volumetric content and 1.05%~12.06% wheat yield within 1.0 H near the shelterbelt,and decreased the reduction of output areas from 1.0 H to 0.5 H near shelterbelt.Root barrier can only minish bad effect of shelterbelt,but cannot eliminate competition.Considering both soil moisture and wheat yield,the root barrier from the nearest shelterbelt showed the best effect.