In oasis irrigation agricultural region, water resources deficit is one of the most penetrating constraints for developing intercropping. However, these was neither sufficient academic basis for enhancing water utilization rate through optimizing chemical nitrogen application, nor available practices for increasing yield and water use efficiency (WUE) of crops in developing cereal/legume intercropping. Here, we carried out a field experiment in Hexi Corridor, a typical arid oasis irrigation area in 2012-2013, and the effect of postponing nitrogen topdressing on yield and water use characteristics of sole- and intercropping maize, pea systems was investigated. The total nitrogen application level for the same cropping system was equal. On the basis of 10%basal N fertilizer plus 50%pre-tasseling N fertilizer, three N treatments were managed with different topdressing amounts postponed:N1, N postponing application with 30%;N2, N postponing application with 15%;and N3, traditional nitrogen applica-tion. The purpose of the study focused on providing academic and practical evidence for increasing yield and WUE through opti-mizing nitrogen fertilizer management. The results showed that, N postponing application had no significant influence on total water consumption (ET) of maize-pea intercropping in the whole growing stage, but the soil evaporation (E) and E/ET were sig-nificantly decreased. As compared with traditional nitrogen application treatment, evaporation and E/ET in 15% N postponing application maize-pea intercropping were reduced by 6%and 4%, respectively, while those in maize-pea intercropping with 30%N postponing application both by 2%. In maize-pea intercropping systems, average soil evaporation in pea strips was 329 mm, but that in maize strips was 232 mm, showing that invalid water consumption in pea strip is significantly higher than that in maize strips. Mixed grain yield of maize-pea intercropping under N postponing application with 15%was 6% higher than that of the traditional nitrogen application treatment. And WUE of pea-maize intercropping systems was also significantly higher than that of the traditional nitrogen by 5%. As well as mixed grain yield and WUE of pea-maize intercropping under N postponing application with 30%was 3%and 2%higher than that of the traditional nitrogen application treatment respectively. Consequently, the 15%N postponing application (topdressing fertilizer with 67.5 kg N ha–1 at pea flower pod period/maize jointing period, topdressing fer-tilizer with 225 kg N ha–1 at maize pre-tasseling period and topdressing fertilizer with 112.5 kg N ha–1 at maize 15 days after flowering period) combined with maize-pea intercropping could be one of the effective strategies to promote grain yield and WUE of cereal-legume intercropping in Oasis irrigation region.%针对水资源不足严重制约干旱灌区间作发展,间作中以氮调水理论研究的薄弱,生产实践中缺乏氮肥运筹同步提高间作产量和水分利用效率的措施等问题。2012—2013年,以河西走廊规模化应用的玉米间作豌豆为研究对象,在总施氮量相同且基肥和孕穗肥分别占10%和50%条件下,设氮肥后移30%(N1,拔节肥0+花粒肥40%)、氮肥后移15%(N2,拔节肥15%+花粒肥25%)、传统制度(N3,拔节肥30%+花粒肥10%)3个施氮处理,探讨氮肥后移对间作产量和水分利用效率(WUE)的影响,以期为禾豆间作优化施氮制度、提高产量和水分利用效率提供理论依据。结果表明,氮肥后移对玉米间作豌豆总耗水量(ET)影响不显著,但降低了棵间蒸发量(E)和棵间蒸发量占总耗水量的比例(E/ET)；与传统施氮处理相比,氮肥后移15%使玉米间作豌豆的E和E/ET降低6%和4%,氮肥后移30%使玉米间作豌豆的E和E/ET均降低2%。在间作系统中,豌豆带、玉米带的棵间蒸发量分别为329 mm、232 mm,表明豌豆带的无效耗水显著高于玉米带。氮肥后移15%间作的混合籽粒产量、WUE较传统施氮间作分别高出6%、5%,氮肥后移30%间作混合籽粒产量、WUE较传统施氮间作分别提高3%、2%。因此,玉米间作豌豆结合氮肥后移15%,即豌豆开花结荚期(玉米拔节期)追施氮肥67.5 kg hm–2、玉米大喇叭口期追施氮肥225 kg hm–2、玉米花后15 d追施氮肥112.5 kg hm–2,可作为绿洲灌区玉米间作豌豆增产和提高WUE的农艺措施之一。
展开▼
