南疆地区田间配置对枣棉间作耗水特性的调控效应

Effects of field collocation patterns on water consumption characteristics of jujube-cotton intercropping system in Southern Xinjiang

为探明农果间作水分高效利用机理,提出适合南疆地区最优的农果间作模式,在大田试验条件下对枣棉间作系统进行研究,以种植模式(枣棉间作和枣、棉单作)和田间配置(棉花种植行数分别为2、4、6行;棉花株距分别为10 cm和12.5 cm)为参试因子,共9个处理,田间随机排列,共27个小区,小区面积为3 m×10 m。测定了各处理的耗水特征、产量、水分利用效率(WUE)和水分当量比(WER)等指标。结果表明:种植模式显著影响复合群体的耗水特性,枣棉间作耗水量较单作加权平均增加9.5%,棵间蒸发量降低11.4 mm,蒸散比降低13.5%。棉花种植行数显著影响复合群体的耗水特性,间作6行棉花较间作2行棉花耗水量增加9.1%~13.9%;间作6行棉花分别较间作4行和2行棉花提高土壤贮水消耗量35.2 mm和66.3 mm,棵间蒸发量分别降低24.2 mm和33.7 mm,蒸散比分别降低16.0%和22.2%;棉花株距变化仅对土壤贮水消耗量有显著影响,I3处理(间作棉花4行)土壤贮水消耗量较I4(间作棉花2行)高24.4 mm,I1(株距10 cm)较I2(株距12.5 cm)高14.7 mm。枣棉间作群体对40~60 cm土层土壤贮水消耗量最高,20~40 cm土层次之,80~100 cm土层最低;单作枣树对土壤深层水分利用较多,单作棉花则主要消耗浅层土壤中的水分,枣棉间作能够较好地利用土壤各层的水分。就土壤贮水利用而言,增加棉花行数或减小株距有助于促进40~80 cm土层土壤贮水的利用。不同枣棉间作处理的WER都大于1,说明枣棉间作较单作提高了农田WUE。间作棉花种植行数为4行、株距为12.5 cm时,枣棉间作综合效益最优,产量为7460 kg·hm^-2,WUE为11.37 kg·mm-1·hm^-2,WER为1.34。

In order to explore the mechanism of high water utilization efficiency in fruit-crop intercropping,we conducted the best fruit-crop intercropping pattern suitable for southern Xinjiang and jujube-cotton intercropping system was studied in the field.Planting modes(intercropping and single cropping)and field allocation(cotton planting rows were 2,4 and 6;cotton plant spacing was 10 cm and 12.5 cm,respectively)were used as test factors.The number of rows planted was 10 rows and plant spacing was 10 and 12.5 cm.A total of 9 treatments and 3 repetitions per treatment were randomly arranged in 27 plots with a plot area of 3 m×10 m.The water consumption characteristics,yield,water use efficiency and water equivalence ratio of each treatment were determined.The results showed that planting mode significantly affected water consumption characteristics of composite population.Water consumption of jujube-cotton intercropping increased by 9.5%on average compared with single cropping.Inter-tree evaporation decreased by 11.4 mm and evapotranspiration ratio(E/ET)by 13.5%.The number of rows planted in cotton significantly affected the water consumption characteristics of the composite population.The water consumption of intercropping 6 rows of cotton increased by 9.1%~13.9%compared with intercropping 2 rows of cotton.Intercropping 6 rows of cotton increased soil water storage consumption by 35.2 mm and 66.3 mm,respectively,compared with intercropping 4 rows and 2 rows of cotton.Inter-tree evaporation decreased by 24.2 mm and 33.7 mm,respectively.E/ET decreased by 16.0%and 22.2%,respectively.The variation of cotton plant spacing only had a significant effect on soil water storage consumption.Soil water storage consumption in I3 treatment(intercropping cotton 4 lines)was 24.4 mm higher than that in I4 treatment(intercropping cotton 2 lines).I1(plant spacing 10 cm)is 14.7 mm higher than I2(plant spacing 12.5 cm).Intercropping group of jujube and cotton had the highest water consumption for soil storage in 40~60 cm soil layer,followed by 20~40 cm soil layer,80~100 cm soil layer was the lowest.Single-cropping jujube trees made more use of deep soil moisture.Cotton monocropping mainly consumed water in shallow soil.Intercropping of jujube and cotton could make better use of water in different soil layers.As far as the utilization of soil water storage was concerned,increasing the number of rows of cotton or decreasing the plant spacing was helpful to promote the utilization of soil water storage in 40~80 cm soil layer.The WER of different intercropping treatments of jujube and cotton were all greater than 1,which indicated that jujube and cotton intercropping improved WUE compared with monoculture.When the number of intercropping rows and plant spacing were 4 and 12.5 cm,the comprehensive benefit of jujube and cotton intercropping was the best,the yield was 7460 kg·hm^-2,WUE was 11.37 kg·mm-1·hm^-2,and WER was 1.34.