Compensation mechanism of increased maize density on yield with water and nitrogen reduction supply in oasis irrigation areas
王菲儿 1郭瑶 2李盼 1韦金贵 1樊志龙 1胡发龙 1范虹 1何蔚 1殷文 1陈桂平1
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作者信息
1. 省部共建干旱生境作物学国家重点实验室/甘肃农业大学农学院,甘肃兰州 730070
2. 西北师范大学生命科学学院,甘肃兰州 730070
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摘要
针对河西绿洲灌区水资源短缺、玉米田氮肥施用量高等生产生态问题,在节水减氮条件下,分析增加种植密度补偿水氮减量导致玉米减产的效应,为水氮节约型玉米高效生产提供理论依据与技术支撑.基于2016年布设的裂裂区田间试验,主区为2种灌水定额:灌水减量20％(W1,3240 m3 hm-2)和传统灌水(W2,4050 m3 hm-2),裂区为2种施氮量:减量施氮25％(N1,270 kg hm-2)和传统施氮(N2,360 kg hm-2),裂裂区为3种玉米密度:传统种植密度(D1,7.50万株hm-2)、增密30％(D2,9.75万株hm-2)和增密60％(D3,12.00万株hm-2),通过测定2020-2021年玉米籽粒产量和生物产量,分析干物质积累及其分配、转运特征,量化产量构成因素,明确增密对水氮减量玉米产量的补偿效应及机制.研究表明,减水、减氮降低了玉米籽粒产量和生物产量,而增密30％能够补偿因水氮同步减量造成的产量负效应,且维持较高的施氮量有利于玉米增产节水.W1N1D1(减量灌水减量施氮及传统密度)较W2N2D1(对照:传统灌水传统施氮及传统密度)籽粒产量和生物产量分别降低9.1％～15.0％与10.0％～11.0％,但W1N1D2(减量灌水减量施氮及增密30％)与W2N2D1差异不显著.W1N2D2(减量灌水传统施氮及增密30％)较W2N2D1籽粒和生物产量分别提高12.9％～15.4％与6.4％～12.0％.增密30％能够补偿水氮同步减量造成玉米减产的主要原因是W1N1D2能增加玉米穗数,进而提高玉米灌浆初期至成熟期干物质积累量和苗期到大喇叭口期群体生长速率及花前转运率.增密30％在灌水减量和传统施氮条件下促进玉米增产的主要原因是W1N2D2可增加玉米穗数,提高玉米生育期干物质积累量与群体生长速率,促进穗部干物质分配,提高花前转运量、转运率及转运贡献率.因此,增密30％是绿洲灌区水氮同步减量玉米稳产高产的可行措施,是氮肥不减但减水20％玉米节水增产有效举措.
Abstract
Aiming at the production and ecological problems of the lack of water resources and excessive chemical nitrogen fer-tilizer input in arid oasis irrigation areas,the effect of increased planting density to compensate for the loss of maize yield caused by reducing water and nitrogen inputs was analyzed under reduced water and nitrogen inputs,which could provide theoretical and technical support for the efficient production of maize with water and nitrogen reduction.Based on a split-plot field experiment conducted in 2016,the main plot was divided into two irrigation quotas:reduced irrigation by 20％(W1,3240 m3 hm-2)and traditional irrigation(W2,4050 m3 hm-2),and the split-plot was divided into two nitrogen application rates:reduced nitrogen(Nl,270 kg hm-2)by 25％and traditional nitrogen(N2,360 kg hm-2)were applied,and the sub-split plot was divided into three maize densities:traditional planting density(D1,75,000 hm-2 plants),increased density by 30％(D2,97,500 hm-2 plants)and increased density by 60％(D3,120,000 hm-2 plants).We measured grain yield and biological yield of maize in 2020 and 2021,analyzed the characteristics of dry matter accumulation,distribution,and transport characteristics,quantified the yield composition factors,and clarified the compensation effect and mechanism of densification on maize yield with water and nitrogen reduction.The study showed that water and nitrogen reduction inputs decreased the grain yield and biological yield in maize,but the increased density by 30％can compensate for the loss of yield due to reducing water and nitrogen inputs and improve maize yield under reduced water while maintaining traditional nitrogen.The grain yield and biological yield of W1N1D1(reduced water and nitrogen and traditional density)was 9.1％-15.0％and 10.0％-11.0％lower than W2N2D1(comparison:traditional irrigation,traditional nitro-gen application,and traditional density),but there was no significant difference in W1N1D2(reduced irrigation,reduced nitrogen,and increased density by 30％)compared with W2N2D1.Compared with W2N2D1,W1N2D2(reduced irrigation,traditional nitrogen,and increased density by 30％)increased grain yield and biological yield by 12.9％-15.4％and 6.4％-12.0％,respec-tively.Increased density by 30％compensated for the negative effect of water and nitrogen reduction mainly attributed to improv-ing spike number of W1N1D2,which further increased dry matter accumulation from the early-filling stage to the maturity stage in maize,population growth rate and dry matter remobilization at pre-anthesis from seeding stage to the flare opening stage.In-creasing spike number of W1N2D2 improved dry matter accumulation and population growth rate,promoted dry matter distribu-tion in the ear,and increased dry matter remobilization.In addition,the dry matter remobilization efficiency and contribution of dry matter remobilization to grain at pre-anthesis were the main reasons for increasing maize yield with the increased density by 30％under water and nitrogen reduction inputs.Therefore,increasing density by 30％was a feasible measure for simultaneous reduction of water and nitrogen in oasis irrigation area to stabilize and increase maize yield.
关键词
水氮减量/密植/玉米/产量构成/干物质积累/干物质分配与转运
Key words
water-nitrogen reduction/dense planting/maize/yield components/dry matter accumulation/dry matter distribution and transportation
维普
万方数据