非灌溉条件下播前深松对冬小麦水分利用和产量的影响

Effects of Subsoiling before Sowing on Water Utilization and Dry Matter Production of Winter Wheat without Irrigation

为了解华北地区深松土壤的蓄水保墒节水和增产效果，在中国农业大学吴桥实验站，对播前深松＋旋耕（S）和旋耕（N）两种耕作方式下非灌溉冬小麦田的土壤容重和水分及小麦根条数、干物质生产和水分利用进行了评价。结果表明，与N处理相比，S处理下0～35cm土层的容重显著降低，越冬期、返青期、拔节期、开花期和成熟期的土壤蓄水量分别提高35．8、34．2、23、80和41．3mm，越冬期和拔节期根数显著增加，花前干物质积累量、生物产量和籽粒产量分别增加28．1％、16．3％和23．2％，花后干物质积累量变化不明显，同时耗水量降低28．7mm，籽粒产量水分利用效率提高39．3％。因此，冬小麦播前深松在降水量稀少的华北地区应该大力推广。

Subsoiling as a way of conservation tillage could break up the plough pan and increase infil- tration of rainfall, but the mechanism of keeping and saving water of subsoiling without irrigation hasn＇t known yet in the North China Plain （NCP）, where long-term rotary tillage has caused soil corn paction and made plough pan move up, with less precipitation in the winter wheat season. A field ex- periment contained subsoiling ＋ rotary tillage（S） and rotary tillage （N） was carried out without irri- gation in Wuqiao experimental station, China Agricultural University . Soil bulk density, variation of soil water during the growth stage, root number and dry matter production were investigated, water utilization of two treatments was assessed at last. The results showed that compared with rotary till- age （N）, subsoiling ＋ rotary tillage（S） notably reduced soil bulk density, and soil water in 0~35 cm soil at over-winter, returning green, jointing, flowering and maturity stages was enhanced by 35. 8 mm,34.2 mm,23 mm,80 mm,41.3 mm, respectively; meanwhile, root number at over-winter and jointing stages was increased significantly, compared with rotary tillage. Dry matter before flowering, biomass yield and grain yield in S treatment was increased by 28.1%, 16.3% and 23.2~, respecta- bly, compared with N field; but S treatment did not improve dry matter after flowering, at the sametime, water consumption of S treatment was reduced by 28.7 mm , and water use efficiency was in- creased by 39.3%, comparing with N treatment. Therefore, in the NCP with less rainfall in the win- ter wheat season, subsoilng before sowing winter wheat should be used widely.