优化氮肥配置提高冬小麦-夏玉米贮墒旱作栽培水氮利用效率

为探明与冬小麦-夏玉米周年贮墒旱作节水栽培模式相配套的氮肥高效施用技术,基于贮墒旱作栽培(冬小麦和夏玉米灌底墒水或出苗水,生育期内不灌水),在全年施氮量360 kg/hm2下开展了前后茬作物施氮量配比不同的大田试验.试验设置4种施氮处理,分别为冬小麦120 kg/hm2+夏玉米240 kg/hm2(W0N1);冬小麦1...

Improving water and nitrogen use efficiency of no-irrigating winter wheat-summer maize under storing available water before growing by optimizing nitrogen fertilizer allocation

In order to clarify the high-efficiency application technology of nitrogen fertilizer matched with the cultivation mode of no-irrigating winter wheat-summer maize under storing available water before growing, in this study, field experiment with different nitrogen application rates of previous and subsequent crops was carried out under the annual nitrogen application rate of 360 kg/hm². The experiment included four nitrogen treatments: 1)120 kg/hm² for winter wheat + 240 kg/hm² for summer maize + no irrigation in spring(W₀N₁); 2)180 kg/hm² for winter wheat + 180 kg/hm² for summer maize + no irrigation in spring(W₀N₂); 3)240 kg/hm² for winter wheat + 120 kg/hm² for summer maize + no irrigation in spring(W₀N₃); and 4)180 kg/hm² for winter wheat + 180 kg/hm² for summer maize + traditional irrigation at jointing and anthesis for winter wheat in spring(W₁N_c). The indexes of crop material production and water and nitrogen efficiency were measured. The results showed that: The grain yield and protein content of winter wheat increased, grain yield of summer maize stabilized, anniversary grain yield, water use efficiency and nitrogen use efficiency significantly improved with more nitrogen fertilizer applied at winter wheat season under no-irrigating crop production system. Compared with W₀N₂ and W₀N₁, the annual grain yield of W₀N₃ increased by 3. 20%-5. 17% and 6. 84%-9. 94%, respectively. In addition, there was no significant difference in anniversary grain yield between the W₁N_c and W₀N₃ in wet year, while yield loss by 11. 38% under W₀N₃ was found in the dry year. W₀N₃ always achieved the highest anniversary water use efficiency and nitrogen use efficiency whether it was a dry or wet year. Therefore, more nitrogen fertilizer should be allocated in winter wheat season to improve anniversary grain yield, water use efficiency and nitrogen use efficiency under limited nitrogen application rate and no-irrigation winter wheat-summer maize rotation under storing available water before growing.