高海拔(西藏)半干旱地区玉米全膜双垄沟播栽培技术探析

采用田间试验,设全膜双垄沟播、全膜平作和裸地平作3种种植方式,测定玉米各生育时期的土壤含水量、干物质量、光和速率、产量和产量构成因子,分析不同处理的土壤耗水量、贮水量、含水量垂直变化以及水分利用效率,探讨全膜双垄沟播下玉米土壤水分的动态变化和利用效率。结果表明,覆膜可使玉米出苗提前2 d,促进玉米前期营养生长并提前灌浆5 d,覆膜处理的整个生育期缩短8 d。全膜双垄沟播处理的产量和水分利用效率最高,分别为27 309 kg/hm~2、69.2 kg/(hm~2·mm),同时生育期耗水量最小(394.5 mm),能够提前灌浆,减少灌浆时期耗水量。收获后,全膜平作和裸地平作处理的土壤水分出现亏缺,各土层贮水量均减少,全膜双垄沟播处理的各土层土壤含水量均高于播前。全膜双垄沟播处理的玉米净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)显著高于其他处理,收获时各处理的子粒和秸秆干物质累积量均表现为全膜双垄沟播全膜平作裸地平作。

Application of Double Ridge Mulching and Furrow Planting in Semiarid Areas of Tibet

Drought and low temperature affected the development of maize in semi-arid regions of Tibet. In order to investigate the dynamic changes and utilization efficiency of maize soil moisture in the double ridge mulching and furrow planting, a field experiment was conducted in which three planting modes were established, double ridge mulching and furrow planting(Q), full covered and flat planting(P) and open and flat planting(L). The soil water content, dry matter, Photosynthesis, maize yield and yield components were measured, as well as the soil water consumption, water storage capacity, and vertical change of water content and water use efficiency of different treatments were analyzed. The results showed that the plastic-milled maize emergence 2 d earlier, at the same time, it promoted the pre-vegetative maize growth and early grouting 5 d, and the entire growth period shortened 8 d. The yield and water use efficiency of maize with Q treatment were the highest, 27 309 kg/ha and 69.2 kg/(ha·mm), respectively. The water consumption during the growth period was the lowest(394.5 mm), which could pre-grout and reducewater consumption during filling. After harvest, P and L soil water deficit, which water content of all soil layers decreased compared with sowing, but the opposite of Q treatment. The Pn, Tr and Gs of maize treated with Q were significantly higher than those of other treatments. The dry matter accumulation of grain and straw at harvest showed Q > P > L, respectively.