不同滴灌施肥水平对北疆棉花水分利用率和产量的影响

Effect of drip irrigation and fertilizer application on water use efficiency and cotton yield in North of Xinjiang

为探讨不同滴灌施肥策略对棉花生长、产量、水分利用效率和肥料偏生产力的影响，在新疆石河子，于2012年和2013年棉花生长季，设置5个N-P2O5-K2O施肥水平150-60-30、200-80-40、250-100-50、300-120-60和350-140-70 kg/hm2（分别记为F0.6、F0.8、F1.0、F1.2和F1.4）和3个灌溉水平（60%ETC：W1、80%ETC：W2、100%ETC：W3，ETC是作物蒸发蒸腾量），研究水肥互作对棉花株高、叶面积指数（leaf area index，LAI）、干物质质量、籽棉产量、水分利用效率和肥料偏生产力的影响。2 a的大田试验表明：2 a的W1灌水水平下各施肥处理株高均低于60 cm且叶面积指数小于3.2，除2013年W2F0.6处理外，W2和W3灌水水平下各施肥处理株高介于60～71 cm且叶面积指数介于3.4～4.2，其中W3F1.0，W3F1.2和W3F1.4处理2 a有效铃数均在6.8个/株以上且籽棉产量差异不显著。棉花有效铃数比百铃质量对水肥更加敏感。水分利用效率最高的处理为W2F1.0，2 a分别为1.65和1.52 kg/m3，比产量最高的W3F1.0处理高12%和6%，但其产量比W3F1.0下降约5%。在北疆棉花膜下滴灌施肥条件下，灌水量在100%ETC，施肥量在250-100-50 kg/hm2时，可以获得最高的籽棉产量。灌水量在80%ETC，施肥量在250-100-50 kg/hm2时，可以获得低于最高籽棉产量约5%的籽棉产量和最高的水分利用效率。从节水和生态可持续发展角度来看，灌水量80%ETC、N-P2O5-K2O 250-100-50 kg/hm2为最佳滴灌施肥策略。该研究可为北疆棉花实施有效的膜下滴灌施肥管理提供理论依据。

Water and fertilizer affect a range of physiological processes in the cotton crop and are key factors controlling cotton productivity and yield. Two-year experiments（2012 and 2013） were conducted to evaluate the effects of different fertigation regimes on cotton growth, yield, water use efficiency and partial factor productivity of fertilizers in Shihezi areas of Xinjiang. The fertilization treatment was based on different ratios of N - P2O5 -K2O and the irrigation treatment was based on the crop evapotranspiration （ETC）. Five fertilizer treatments were designed including 60% （F0.6）, 80 （F0.8）, 100% （F1.0）, 120% （F1.2） and 140% （F1.4） of recommended rates with N （250）-P2O5 （100） -K2O （50） kg/hm2, and three irrigation treatments included 60% ETC （W1）, 80% ETC （W2） and 100% ETC （W3）. Irrigation amount was decided by a 20-cm inner diameter evaporation pan. Evaporation pan-crop coefficient in seedling, budding period and flowering period, boll opening period were 0.2, 0.4, 0.7 and 0.25, respectively. During the experiment, plant height, leaf area index and dry mass accumulation, and yield components were measured. Harvest index （HI）, water use efficiency （ratio between yield/irrigation amounts, WUE） and partial factor productivity of fertilizer （PFP） were calculated. The results showed that compared to W3F1.0, plant height, LAI, effective bolls number per plant, seed cotton yield and quality of dry matter and WUE of W1F0.6, W1F0.8, W1F1.0, W1F1.2 and W1F1.4treatments have dropped significantly. Besides W2F0.6 in 2013, W2 and W3 irrigation level under various fertilizer treatments, plant height were between 60 and 71 and LAI were between 3.4 and 4.2. The effective bolls number per plant of W3F1.0, W3F1.2 and W3F1.4 treatments were above 6.8 per plant. Cotton effective bolls number per plant was more sensitive than the 100-boll weight. In 2012 and 2013, the irrigation amount ranged from 291 to 445 mm and from 267 to 392 mm, cotton ET ranged from 277 to 419 mm and from 316 to 438 mm, WUE ranged from 1.27 to 1.65 kg/m3and from 1.27 to 1.52 kg/m3 in 2012 and 2013, respectively. The highest seed cotton yield was obtained in the combination treatments of W3F1.2 and W3F1.0withthe value of 5 896 and 5 888 kg/hm2 in 2012 and 2013, respectively. W2F1.0 combination treatment had the highest WUE. PFP decreased with the increase of fertilization rate but increased with the increased irrigation amount and W3F0.6 combination treatment had the highest PFP. Considering the water shortage condition in the northern Xinjiang Uygur Autonomous Region, the treatment of 80% ETC combined with 250-100-50 kg/hm2 （N-P2O5-K2O） was suggested to be optimal for cotton production since the treatment could save 63 to 77 mm irrigation amount while keeping 95% seed cotton yields compared with the treatment of 100% ETC combined with 250-100-50 kg/hm2 （N-P2O5-K2O）. The saved water accounted for more than half amount of the averaged precipitation in this area. The study can provide valuable information for improving management of cotton crop in North of Xinjiang.