半干旱区氮肥运筹对全膜双垄沟播玉米水肥利用和产量的影响

Effects of optimal nitrogen fertilizer management on water and fertilizer utilization efficiency and yield under double-ridge-furrow sowing with the whole plastic film mulching in maize in a semi-arid area

施肥方式不当是半干旱区全膜双垄沟播玉米水肥利用率低的主要原因之一,研究氮肥减量后移和有机肥替代对玉米水肥利用效率和产量的影响,可为该区玉米水肥高效管理提供理论依据。依托4年大田定位试验,设置3个处理,即肥料全部基施(CK)、减氮15%且在抽雄期追施(RN)、30%的化肥以有机肥替代且在抽雄期追施(RNM),研究不同施肥模式对玉米耗水特性、生长发育和水肥利用效率的影响。结果表明:施肥方式对玉米水肥利用效率和产量有显著调控作用,并与降雨年型密切相关。欠水年和平水年,RN花前耗水量较CK降低16.1%~18.8%,花后耗水量提高18.0%~22.2%;RNM花前、花后耗水量均与CK差异不显著。丰水年,RN和RNM花前耗水量分别较CK降低16.7%和6.3%,花后耗水量分别增加11.4%和29.7%。与CK相比,RN显著提高了追肥后玉米叶片叶绿素相对含量(SPAD值),花后生物量增加15.6%~44.9%,穗长、穗粒数、穗粒重和百粒重显著提高,产量增加9.8%~17.0%,水分利用效率(WUE)提高6.3%~21.4%,肥料偏生产力(PEPT)、氮素偏生产力(PEPTN)、磷素偏生产力(PEPTP)和钾素偏生产力(PEPTK)均显著提高。综上,RN能显著提高不同降水年型下玉米花后耗水量和SPAD值,增加花后生物量,优化穗部性状,使产量、水肥利用效率显著提高,为半干旱区全膜双垄沟播玉米水肥高效利用的有效肥料管理模式。

Improper fertilization style is one of the main reasons for low water and fertilizer use efficiency of double-ridge-furrow sowing with the whole plastic film mulching in maize production in the semi-arid area. Understanding the effects of reduction, postponing, and organic fertilizer substitution of nitrogen fertilizer on water and fertilizer use efficiency and yield of maize can provide theore-tical basis for effective management of water and fertilizer in maize production. Based on a 4-year field experiment with three treatments: all fertilizers as base fertilizer under double-ridge-furrow sowing with the whole plastic film mulching(CK), nitrogen fertilizer reduced by 15% and topdres-sing in tasseling stage(RN), 30% of the chemical fertilizer replaced by organic fertilizer and topdressing in tasseling stage(RNM), we measured water consumption characteristics, growth and development, water and fertilizer utilization efficiency of maize. The results showed that fertilization pattern significantly affected water and fertilizer utilization efficiency and yield of maize, which was dependent on annual rainfall. In dry and normal rainfall year, water consumption in pre-flowering stage of RN was decreased by 16.1%-18.8% and that in post-flowering stage was increased by 18.0%-22.2%, while water consumption in pre-flowering and post-flowering stages of RNM did not differ from that in CK. In wet year, water consumption in pre-flowering stage of RN and RNM was decreased by 16.7% and 6.3%, while that in post-flowering stage was increased by 11.4% and 29.7%, respectively. Compared with CK, RN significantly increased the relative content of chlorophyll(SPAD) of maize leaves after topdressing, the biomass in post-flowering stage was increased by 15.6%-44.9%, the ear length, the number and weight of grains per spike and the 100-grain weight were increased significantly, yield was increased by 9.8%-17.0%, and water use efficiency(WUE) was increased by 6.3%-21.4%, with the partial productivities of fertilizer(PEPT), N(PEPTN), P(PEPTP) and K(PEPTK) were all increased significantly. In conclusion, RN could improve water consumption and the SPAD value in post-flowering stage of maize in different precipitation years, increase post-flowering biomass, and optimize the ear character, obviously improve yield, water and fertilizer use efficiency. It was a effective fertilizer management mode with high-efficiency utilization of water and fertilizer under double-ridge-furrow sowing with the whole plastic film mulching in maize in the semi-arid area.