不同种植方式对棉田土壤温度、棉花耗水和生长的影响

通过2010-2011年大田试验,研究了平作、沟播和地膜覆盖(沟播+地膜覆盖)下棉花生长、水分消耗以及棉田地温变化情况.结果表明:地膜覆盖对棉花苗期和现蕾期地温日变化、最高温影响最大,通过提高土壤温度的最高值来影响土壤温度变化,开花结铃期以后种植方式对地温的影响不明显；不同种植方式对土壤水分也产生了一定影响,覆膜处理的土壤含水量高于其他2种处理,2010年覆膜和沟播处理比平作处理下的水分利用效率分别提高62.4％和25.3％,2011年为26.1％和10.3％；覆膜处理下的棉花净光合速率、生物量和籽棉产量都高于平作和沟播处理,而沟播与平作间的差异不明显；与平作相比,2010和2011年覆膜和沟播处理下的棉花水分利用效率分别提高了0.17、0.10 kg·m-3和0.10、0.03 kg·m-3.覆膜处理与沟播和平作处理相比,能够提高棉花生育前期的地温,有效地保持土壤水分,有利于棉花增产,最终提高了水分利用效率.

Effects of different planting patterns on soil temperature, water use and growth of cotton

This study was undertaken to examine the effects of flat planting, furrow sowing and film-mulching-bed planting on soil temperature, water use and growth of cotton. Results showed that film mulching bed planting increased soil temperature by increasing the daily maximum temperature in the early growth stages of cotton. After flowering, the effects were not obvious. At the same time film-bed and furrow sowing could conserve soil water and reduce soil evaporation. The amount of field water use under film-bed planting was significantly lower than that under furrow and flat sowing by 62.4% and 25.3% in the growth season of 2010, while by 26.1% and 10.3% in 2011. As a result, cotton net photosynthetic rate, biomass and final yield under film-mulching-bed planting were higher than that under furrow and flat planting. Compared with flat sowing, water use efficiency under film-bed and furrow planting was obviously improved by 62.4% and 25.3% for the season of 2010, while by 26.1% and 10.3% in 2011. Though furrow planting was better in soil moisture conservation than flat planting, no significant difference was found on the cotton yield of the two practices.