摘要
【目的】探究不同水平氮磷配施对夏玉米地上部生物量和氮素浓度的影响,构建临界氮浓度稀释曲线模型,并基于氮营养指数模型诊断和评价玉米在不同氮磷互作条件下的氮素营养状况,可为夏玉米氮磷肥合理施用提供理论依据。【方法】以玉米品种郑单958和豫玉22为试验材料,在陕西关中平原设置田间定位氮磷配施试验,设氮肥(N)用量0、75、150、225、300 kg·hm^(-2)(分别用N0、N1、N2、N3和N4表示);磷肥(P_(2)O_(5))用量0、60、120、180 kg·hm^(-2)(分别用P0、P1、P2和P3表示),于2019-2020年在夏玉米拔节期、抽雄期、灌浆期和成熟期进行取样,分析不同水平氮磷配施对玉米地上部生物量累积、氮浓度动态变化和产量的影响,构建并验证临界氮浓度稀释曲线模型。【结果】氮磷配施能显著提高夏玉米地上部生物量、植株氮浓度及籽粒产量,在同一施磷水平下,随施氮水平的提高,夏玉米各生育时期地上部生物量和籽粒产量呈增加趋势,植株氮浓度随生育进程推进和地上部生物量积累的增加而降低,氮浓度和地上部生物量之间符合幂指数关系。同时,施磷能促进植株氮素吸收和地上部生物量积累,在相同施氮条件下,施磷各处理总体表现为P2>P3≈P1>P0,说明施磷可以提高植株氮容纳能力,减缓氮浓度下降速率。根据地上部生物量(DM)与其氮浓度变化关系构建不同施磷水平下夏玉米临界氮浓度(N_(c))变化曲线(P0,N_(c)=27.98DM-0.249;P1,N_(c)=29.77D^(-0.182);P2,N_(c)=30.81DM^(-0.138);P3,N_(c)=30.06DM^(-0.187)),模型拟合的植株氮浓度和实际氮浓度线性相关,稀释曲线模型的n-RMSE值分别为10.23%、6.67%、6.95%和7.19%,有很好的稳定性。基于临界氮浓度稀释曲线计算氮营养指数(NNI),同一施磷水平下玉米各生育时期NNI随氮肥用量的增加而增大,NNI与相对地上部生物量(RDW)和相对产量(RY)均呈极显著相关。【结论】基于临界氮�
【Objective】This study investigated the effects of different nitrogen and phosphorus application rates on summer maize aboveground biomass,nitrogen accumulation,and drew a critical nitrogen concentration dilution curve.The nitrogen status of maize plant was diagnosed and evaluated based on a model of nitrogen nutrition index(NNI)under different nitrogen and phosphorus interaction conditions,which provided a theoretical basis for the rational application of nitrogen and phosphorus fertilizers in summer maize.【Method】By using Zhengdan958(ZD958)and Yuyu22(YY22)as tested materials,the field experiments in Guanzhong Plain,Shaanxi included four phosphorus application rates and five nitrogen application rates,such as 0(P0),60(P1),120(P2),180(P3)kg P_(2)O_(5)·hm^(-2) and 0(N0),75(N1),150(N2),225(N3),300(N4)kg N·hm^(-2) during 2019-2020.The aboveground samples were taken during the jointing,tasseling,filling,and maturity stages of summer maize to analyze the effects of nitrogen and phosphorus application rate on maize dry matter accumulation,dynamic changes of nitrogen concentration and grain yield.The field test data was used to construct and verify the critical nitrogen dilution curve model of summer maize.【Result】The results showed that nitrogen and phosphorus application rate significantly increased aboveground biomass,plant nitrogen concentrations and grain yield of summer maize.The grain yield and aboveground biomass of summer maize increased as the nitrogen application rate increased within the same phosphorus application condition.The nitrogen concentration of maize plants showed a decreasing trend with the extension of growth period and the increase of aboveground dry matter weight.There was a power exponential relationship between nitrogen concentration and aboveground biomass.In addition,the phosphorus application could promote maize plant nitrogen absorption and aboveground dry matter accumulation.The overall performance of the phosphorus application treatments was P2>P3≈P1>P0 under the same nit
作者
刘苗
刘朋召
师祖姣
王小利
王瑞
李军
LIU Miao;LIU PengZhao;SHI ZuJiao;WANG XiaoLi;WANG Rui;LI Jun(College of Agronomy,Northwest A&F University/Key Laboratory of Crop Physio-ecology and Tillage Science in Northwestern Loess Plateau,Ministry of Agriculture and Rural Affairs,Yangling 712100,Shaanxi)
出处
《中国农业科学》
CAS
CSCD
北大核心
2022年第5期932-947,共16页
Scientia Agricultura Sinica
基金
国家科技支撑计划(2015BAD22B02)
国家高技术研究发展计划(2013AA102902)
国家自然科学基金(31801300)。
关键词
夏玉米
氮磷配施
临界氮稀释曲线
氮营养指数
summer maize
nitrogen and phosphorus application rate
critical nitrogen dilution curve
nitrogen nutrition index
