关键词: 间作, 氮肥后移, 棵间蒸发, 产量, 水分利用效率

Abstract:

【Objective】Aiming at the problem of insufficient excavation of the potential of efficient water utilization of wheat-maize intercropping in the oasis irrigation area, which restricted the stable development of multi-maturing cultivation, this study was intended to provide the theoretical basis for the creation of a model of efficient water utilization of wheat-maize intercropping in the oasis irrigation area by investigating the effects of different nitrogen fertilizer postponing application on water consumption characteristics and water utilization of wheat-maize intercropping.【Method】The experiment was carried out in the oasis agricultural comprehensive experimental station of Gansu Agricultural University from 2020 to 2021. Three planting patterns of wheat-maize intercropping, monocropping wheat and monocropping maize were set up. Four treatments application systems were set up for maize: no nitrogen application (N0), 20% nitrogen fertilizer postponing (N1), 10% nitrogen fertilizer postponing (N2), and traditional nitrogen fertilizer without postponing (N3). The total nitrogen application rates of intercropping maize and monocropping maize were 210 and 360 kg·hm^-2, respectively. The effects of different planting systems and nitrogen fertilizer postponing ratios on soil evaporation, water consumption characteristics and water use of wheat and maize were studied.【Result】During wheat and maize independent growth stage, the intercropping tree evaporation was greater than that of monocropping, the intercropping wheat tree evaporation increased 15.9%-16.7% than that of monocropping wheat, and the intercropping maize tree evaporation increased 5.4%-14.7% than that of monocropping maize, while wheat and maize symbiosis of intercropping tree evaporation compared with the monocropping weighted reduction of 4.6%-6.1%; the total amount of evaporation during the whole life cycle tree performance: wheat maize in the intercropping mode, intertree evaporation was reduced by 6.5% in the 20% N fertilization setback treatment compared with N3, and intertree evaporation in the wheat belt increased by 12.6%-17.3% compared with that in the maize belt, which was the main source of intertree evaporation in the intercropping system. In the intercropping system, water consumption was 34.3 and 18.9 mm lower than that of traditional N application under the 20% and 10% N fertilizer setback treatments, respectively, but the difference between E/ET and traditional N application was not significant. The seed yield of intercropping system was increased by 21.1%-39.0% compared with the weighted average of monocrop, and the seed yield of intercropping system with 20% N fertilizer setback treatment was increased by 28.8% compared with the traditional N application, among which the intercropped wheat and intercropped maize with 20% N fertilizer setback treatments were increased by 24.3% and 30.8%, respectively, compared with the traditional application of N. The water consumption during the whole growth period under intercropping system with 20% and 10% N fertilizer setback treatment was decreased by 34.3 and 18.9 mm that under traditional application of N, respectively. The E/ET of intercropping system with 20% N fertilization was increased by 20% than that under the traditional N application. The water use efficiency of intercropping planting pattern nitrogen fertilizer setback treatment was significantly increased by 15.0% and 12.3% than that under the weighted average of monocrops; among which the nitrogen fertilizer setback 20% treatment was increased by 35.9% compared with the traditional nitrogen application, and the nitrogen fertilizer setback 10% treatment was increased by 19.3% compared with the traditional nitrogen application.【Conclusion】The wheat-maize intercropping pattern combined with 20% nitrogen fertilizer postponing could reduce soil evaporation and water consumption during the whole growth period, and increase yield and water productivity, which was a nitrogen application system that could be used for high-yield and high-efficiency production of wheat-maize intercropping in oasis irrigation areas.

Key words: intercropping, nitrogen fertilizer postponing application, soil evaporation, yield, water use efficiency