灌水施氮和缩节胺用量对南疆棉花产量品质和水肥利用效率的影响

Effects of irrigation amount,nitrogen rate and mepiquat chloride dose on cotton yield,quality and water-fertilizer use efficiency in Southern Xinjiang of China

为研究灌水量、施氮量和缩节胺用量对棉花籽棉产量、纤维品质和水肥利用效率的交互影响,于2020年和2021年在南疆库尔勒地区开展大田试验,设置3个灌水量(W1:60%ETc,W2:80%ETc,W_(3):100%ETc,ETc为作物蒸发蒸腾量),4个施氮量(N0:0,N200:200 kg/hm^(2),N_(300):300 kg/hm^(2),N_(400):400 kg/hm^(2))和2个缩节胺用量(D_(1):120 g/hm^(2),D_(2):240 g/hm^(2))。结果表明:灌水量、施氮量和缩节胺用量对籽棉产量、水分利用效率、肥料偏生产力和部分纤维品质指标影响显著(P<0.05)。灌水量、施氮量和缩节胺用量三者交互作用对肥料偏生产力和纤维品质影响显著(P<0.05)。株高、叶面积指数和干物质量也受灌水量、施氮量和缩节胺用量三者交互作用影响。W_(3)N_(300)D_(2)处理籽棉产量最高(2020年为7578 kg/hm^(2),2021年为7173 kg/hm^(2)),W1N_(400)D_(1)处理水分利用效率和W_(3)N0D_(2)处理肥料偏生产力最高,W_(3)N_(400)D_(2)处理的纤维长度、纤维强度和马克隆值均获得较大值,纤维品质最佳。基于TOPSIS综合评价方法对棉花产量品质和水肥利用效率进行综合评价,100%ETc灌水量、300 kg/hm^(2)施氮量和240 g/hm^(2)缩节胺用量组合最优,可作为南疆棉花适宜的水氮和化控管理模式。研究结果可为南疆棉花水肥高效利用提供理论依据和科学指导。

Xinjiang has been one of the major cotton-producing areas in China.The yield and quality of cotton have been seriously limited to irrigation and fertilization,as well as the use efficiency of water and fertilizer resources.Irrigation,nitrogen fertilization,and mepiquat chloride have been widely used in the cotton production in recent years.This study aims to explore the interactive effects of irrigation amount,nitrogen rate,and mepiquat chloride dose on seed cotton yield,fiber quality,and water-fertilizer use efficiency.The field experiments were also carried out in the Korla region of Southern Xinjiang in 2020 and 2021,including three irrigations(W1:60%ETc,W2:80%ETc,and W_(3):100%ETc,where ETc was the crop evapotranspiration),four nitrogen rates(N0:0 kg/hm^(2),N200:200 kg/hm^(2),N_(300):300 kg/hm^(2),and N_(400):400 kg/hm^(2)),and two doses of mepiquat chloride(D_(1):120 g/hm^(2),and D_(2):240 g/hm^(2)).The planting mode was adopted as"one film,two pipes,and four rows".The fertilizer was dissolved in the irrigation water eight times for drip fertilization.The foliar spraying of mepiquat chloride was conducted using a manual knapsack sprayer.Some indicators were measured(such as the plant height,leaf area index,dry matter accumulation,seed cotton yield,and fiber quality)to calculate the crop evapotranspiration,water use efficiency,and partial factor productivity of fertilizer.The results showed the irrigation amount,nitrogen rate,and mepiquat chloride dose significantly dominated the seed cotton yield,water use efficiency,partial factor productivity of fertilizer,and some indicators of fiber quality(P<0.05).Furthermore,their three-factor interaction also depended on the partial factor productivity of fertilizer and fiber quality(P<0.05).The irrigation amount increased the plant height,leaf area index,and dry matter accumulation,while the trend of nitrogen rate was the first increase and then decrease.The leaf area index of each treatment showed an S-shaped curve,as the growth period progressed,thus increasing rapidly during the seedling and bud stages,and then reaching a peak at the flowering stage.Plant height and leaf area index decreased,whereas,the dry matter accumulation increased when the dose of mepiquat chloride increased from 120 to 240 g/hm^(2).The effective boll number of D_(1) increased with the increase in the nitrogen rate,while the effective boll number of D_(2)increased first and then decreased.The increasing irrigation amount and mepiquat chloride dose improved the boll weight and seed cotton yield,while the nitrogen rate led to the increasing boll weight,but with increasing and then decreasing seed cotton yield.The W_(3)N_(300)D_(2)had the highest dry matter accumulation,effective boll number per plant,and seed cotton yield.The W_(3)N_(300)D_(1) had the highest plant height and leaf area index.The maximal seed cotton yield(7578 kg/hm^(2)in 2020 and 7173 kg/hm^(2)in 2021)occurred in W_(3)N_(300)D_(2).The partial factor productivity of fertilizer increased,while the water use efficiency decreased,as the irrigation amount increased.The mepiquat chloride dose improved the water use efficiency and partial factor productivity of fertilizer.The highest performance was achieved in the water use efficiency of W1N_(400)D_(1) and the partial factor productivity of fertilizer of W_(3)N0D_(2).Fiber length increased with the increasing nitrogen rate under W1 and W2.There was the first increase and then a decrease with the increase of nitrogen rate under W_(3),where the maximum was obtained under N_(300).The mepiquat chloride dose also decreased the fiber strength and micronaire value.The fiber length,fiber strength,and micronaire value of W_(3)N_(400)D_(2)were all obtained from the larger values,where the fiber quality was the best.Six indicators were selected from three aspects(yield,water-fertilizer use efficiency,and fiber quality)in the TOPSIS evaluation.The best combination was achieved in the irrigation amount of 100%ETc,nitrogen rate of 300 kg/hm^(2),and mepiquat chloride dose of 240 g/hm^(2),suitable for the water-fertilizer and chemical control practice of cotton in southern Xinjiang.The findings can provide a theoretical basis and scientific guidance for the efficient utilization of water and fertilizer in cotton production in southern Xinjiang China.