沟垄覆膜集雨栽培对冬小麦水分利用效率及产量的影响

 在半湿润易旱地区的关中红油土上, 研究了垄上覆膜集雨保墒和沟内种植栽培方法对冬小麦(Triticumaestivum )水分利用效率及产量影响。结果表明,冬小麦返青时各处理100～200 cm深土层的水分与播前相比无变化。0～100 cm土层覆膜较未覆膜多保蓄水6.5 mm,有一定集水保水作用。收获时各土层的水分都明显减少。在低氮(75 kg·ha-1)、低密(230万株·ha-1)和高氮(225 kg·ha-1)、高密(280万株·ha-1)2种条件下,覆膜较未覆膜处理平均多耗水34.8 mm,表明小麦明

Effects of Plastic Sheet-mulching on Ridge for Rainwater-harvesting Cultivation on WUE and Yield of Winter Wheat

A field experiment was conducted in a manural loessial soil in middle of Shaanxi Province, a sub-humid areaprone to drought, to study the effects of rainwater-harvesting cultivation on water use efficiency (WUE) and yield of winterwheat. Ridge-furrow tillage was used, the ridge being mulched by plastic sheets for rainwater harvesting while seeding inthe furrows. Results showed that from sowing to reviving stage of winter wheat, water stored in 0 -100 cm layer wassignificantly decreased whereas that in 100 - 200 cm layer was not changed. Compared to the non-mulching, plastic sheet-mulching retained 6.5 mm more water as an average of the two N rate treatments, having a certain effect on conservation ofsoil moisture. In contrast, at harvest, water was remarkably reduced in both the 0 -100 cm and the 100-200 cm layers, andmulched plots consumed 34.8 mm more water as an average of the two treatments: low N rate (75 kg Nha-1) with low plantdensity (2 300 000 plantsha-1) and high N rate (225 kgha-1)with high plant density (2 800 000 plantsha-1), in 0-200 cm layerthan those without mulching, the former being beneficial in utilization of deep layer water. Mulching was significant inharvesting water and in increase of yield. Mulched with plastic sheets, biological and grain yields were 22.5% and 22.6%higher for the average of the high N rate than for the low N rate, and the high N rate with low plant density was 29.8% and29.1% higher in both biological and grain yields than that of the low N rate with low plant density. With high N rate and highplant density, the mulched biological and grain yields were 39.5% and 28.9% higher than the corresponding treatmentswithout mulching. Of the treatments, that with high N rate and low plant density was the highest in both biological and grainyields, and the water use efficiency reached 43.7 kgmm-1ha-1 for biological yield and 22 kgmm-1ha-1 for grain yield.