不同覆膜方式对旱地冬小麦土壤水分和产量的影响

Effects of Plastic Mulching Modes on Soil Moisture and Grain Yield in Dryland Winter Wheat

为探讨黄土高原半干旱雨养条件下覆膜种植冬麦田土壤水分动态特征和增产效果,在2008—2009和2009—2010年生长季,以露地种植为对照（CK）,研究了3种覆膜方式（全膜覆土穴播、全膜穴播、垄膜沟播）对冬小麦农田土壤水分、产量和水分利用效率的影响。结果表明,孕穗前期覆膜处理0~200 cm平均土壤含水量在2个生长季分别较CK高2.3%和1.7%,而在孕穗期至成熟期分别较CK低14.7%和7.6%。地膜覆盖可显著改善0~20 cm土壤墒情,但拔节后20~90 cm土层以及全生育期90~200 cm土层含水量普遍低于CK;2个生长季收获期0~200 cm平均土壤含水量覆膜处理较CK分别低64.7 mm和47.0 mm。在2个生长季中,覆膜处理平均耗水量分别较CK多64.6 mm和77.2 mm。2个生长季夏季休闲后,覆膜处理在秋播时0~200 cm的土壤含水量分别比CK高29.8 mm和22.8 mm,显然,覆膜有利于土壤水分的快速恢复。2个生长季覆膜处理的平均产量分别较CK高49.4%和53.2%,水分利用效率分别提高11.8%和14.3%。在3种覆膜处理中,虽然全膜穴播的产量和水分利用效率最高,但从劳动力和生产资料的投入同产出效益角度考虑,则以全膜覆土穴播最优。因此认为,全膜覆土穴播是一种高产高效、操作简单、适宜于半干旱区推广应用的冬小麦种植方式。

Mulching strategies and practices are required to increase crop yields in arid and semiarid rainfed areas. This study was carried out to determine the effect of different mulching modes on soil moisture, grain yield, and water use efficiency for winter wheat in a semiarid rainfed region of Loess Plateau, Northwest China during 2008–2009 and 2009–2010 growing seasons. Winter wheat was grown under four cultivation patterns： whole field plastic mulching with soil cover on the top of the plastic mulch and bunch-seeding（T1）, whole field plastic mulching without soil cover on the top of the plastic mulch and bunch-seeding（T2）, ridges mulched with plastic film and row-seeding in the furrow（T3）, and non-mulching with row-seeding as control（CK）. Compared with CK, the three plastic mulching treatments showed the increase of water storage in the 0–200 cm soil layer before booting stage by 2.3% in the 2008–2009 season and 1.7% in the 2009–2010 season and the decrease of 0–200 cm soil water storage from booting to harvest by 14.7% and 7.6% in the two seasons, respectively. In the three plastic mulching treatments, the 0–20 cm soil moisture during the whole growth season was obviously higher than that in CK, however the 20–90 cm soil moisture after jointing and the 90–200 cm soil moisture during the whole growth season were lower than that in CK. As a result, the 0–200 cm soil water storage at harvest in the plastic mulching treatments was 64.7 mm（2008–2009 growing season） and 47.0 mm（2009–2010 growing season） lower than that in CK. Although T1, T2 and T3 consumed 64.6 mm and 77.2 mm more soil water than CK in two growing seasons, the 0–200 cm soil water storage was 29.8 mm and 22.8 mm higher at seeding stage in autumn after the summer fallowing. This result indicated that soil water storage was restored rapidly during summer fallow in plastic mulching treatments. Compared with CK, plastic mulching treatments enhanced wheat yield by 49.4% in 2008–2009 season and 53.2% in 2009–2010 season and water use efficiency by 11.8% in 2008–2009 season and 14.3% in 2009–2010 season. In a comprehensive consideration of yield, water use efficiency and economical return, T1 is recommended as a simple and applicable technique in semiarid rainfed wheat production aiming at high yield and high efficiency.