北疆“滴灌小麦-青贮玉米”免耕复种体系耗水特性研究

To explore the water saving and efficient irrigation system this study researched on the effect of irrigation amount and irrigation frequency on crop yield, dry matter accumulation, water consumption and water use efficiency, by setting up different samples in the drip irrigation wheat - silage corn no-till cropping system. In the optimal irrigation system, water content in different levels was regular observed through the soil profile moisture measuring instrument. And storage soil water consumption in different growth stage was calculated so that crop water consumption could be calculated through the field water balance equation. Meanwhile, combining the dual crop coefficient approach recommended by FAO - 56 with the penmen formula in the multiple cropping system water requirements of crop in different growth stages were calculated. By comparing the two, to explore the multiple cropping system character of water consumption, water consumption modulus and water use efficiency. The results of this study will be beneficial to improve water use efficiency of the "drip irrigation of wheat - silage maize " no-till double cropping system, and provide theoretical and technical support to set up the system with stable and high yield, efficient utilization of resources, food security guarantee, agriculture and animal husbandry combination promotion, agricultural industrial structure adjustment, transformation from "grain and cotton" dual dimension structure to "grain, economic crop and feed crop" three dimension structure and the high efficient and sustainable development of agriculture.

本研究通过对“滴灌小麦-青贮玉米”免耕复种体系中小麦和后茬作物青贮玉米分别设置不同灌水量、灌溉频率处理，研究其对作物产量、干物质积累、耗水和水分利用效率的影响，探索该体系水资源节约高效利用的灌溉制度。在优化配置的灌溉制度下，通过土壤剖面水分测量仪对不同层次土壤水分进行定期观测，计算得出各生育阶段土壤贮水消耗量，通过农田水量平衡方程算出农田作物耗水量；同时，采用FA0 -56推荐的双作物系数方法，结合彭曼公式计算该复种体系在两茬作物各生育阶段的作物需水量情况，二者加以比较，探索整个复种体系耗水量、耗水模数和水分利用效率等特性。本研究结果将有利于提高“滴灌小麦-青贮玉米”免耕复种体系水分利用效率，为该体系的持续稳定高产、资源高效利用、保障粮食安全、促进农牧结合、进行农业产业结构调整、从“粮、棉”二元结构向“粮、经、饲”三元结构转变以及农业的持续高效发展提供理论与技术支撑。

新疆地域辽阔，光、热和土地资源丰富，是国家粮食战略后备基地，同时，也是全国4大奶源带之一。随着近些年农业结构的调整，畜牧业日渐成为当地农业重点发展方向，而饲料的供应成为生产实践中亟待解决的问题。在北疆“滴灌春小麦免耕复播青贮玉米”种植模式因其不额外占用耕地、粮饲兼顾而恰逢其时，发展势头旺盛。但地处我国西北干旱半干旱地区的新疆水资源严重短缺，绝大部分地区只能开展灌溉农业，无灌溉则无农业。大量“一年两作”种植模式的开展势必增加农业用水压力。本项目通过对“滴灌春小麦-青贮玉米”免耕复种体系前后茬设置不同灌溉量和灌溉频率处理，通过农田水量平衡方程、彭曼公式，结合相应气象资料和数据资料，对该复种体系土壤水分时空分布、土壤贮水量变化、农田作物耗水量、两茬作物参考作物蒸发蒸腾量变化、与气象因子的关系、作物蒸发蒸腾量及作物耗水系数等进行测算和分析，研究了“滴灌小麦-青贮玉米”免耕复种体系的耗水特性，从作物产量、水分利用率、经济效益等方面比较分析，得出该种植模式较优化合理的灌溉制度为春小麦 300 mm灌溉量、滴灌 5 次，青贮玉米 220 mm、滴灌 3 次。该研究结果可在保障粮食安全及人们生活、生产对农产品的基本需求前提之下，减少农业用水所占比重，为缓解水资源紧张局面、保障粮食安全同时兼顾畜牧业发展提供理论支持。