Determining nitrogen status and quantifying nitrogen fertilizer requirement using a critical nitrogen dilution curve for hybrid indica rice under mechanical pot-seedling transplanting pattern  

作　　者：YAO Bo HE Hai-bing XU Hao-cong ZHU Tie-zhong LIU Tao KE Jian YOU Cui-cui ZHU Dequan WU Li-quan 

机构地区：[1]College of Agronomy,Anhui Agricultural University,Hefei 230000,P.R.China [2]Jiangsu Collaborative Innovation Center for Modern Crop Production,Nanjing 210095,P.R.China

出　　处：《Journal of Integrative Agriculture》2021年第6期1474-1486,共13页农业科学学报（英文版）

基　　金：the National Key R&D Program of China(2016YFD0300608,2016YFD0300505 and 2017YFD0301305);the Key Research and Development Program of Anhui Province,China(1804h07020150)。

摘　　要：Field experiments of nitrogen(N)treatment at five different application rates(0,75,150,225,and 300 kg ha^(-1))were conducted under pot-seedling mechanical transplanting(PMT)in 2018 and 2019.Two high-quality and high-yielding hybrids of indica rice,Huiliangyou 898 and Y Liangyou 900,were used in this study.The N nutrition index(NNI)and accumulated N deficit(N_(and)),used to assess the N nutrition status in real-time,were calculated for the indica cultivars under PMT with a critical nitrogen concentration(N_(c))dilution model based on shoot dry matter(DM)during the whole rice growth stage.The relationships between NNI and N_(and) with relative yield(RY)were determined,and accurate N application schemes were developed for hybrids indica rice under PMT.The results indicated that high application rate of N-fertilizer significantly increased the concentrations of shoot DM and N in aboveground organs during the observed stages in the two cultivars for two years(P<0.05).The N_(c) dilution model of hybrid indica cultivars was N_(c)=4.02 DM^(-0.42)(R^(2)=0.97)combining the two cultivars under PMT.Root-mean-square error and normalized root-mean-square error of the curve verification were 0.23 and 10.61%,respectively.The NNI and Nand ranged from 0.58 to 1.31 and 109 to–55 kg ha^(-1),respectively,in the two cultivars for all N treatments.NNI showed a linear relationship with Nand during the entire growth stage(0.53<R^(2)<0.99,P<0.01).In addition,NNI showed a linear-plateau relationship with RY(0.73<R<0.92,P<0.01)throughout the observed stages.These results suggest that the models can accurately diagnose the N-nutrition status and support effective N-fertilizer management in real-time for hybrid indica rice under PMT.

关 键 词：rice yield critical nitrogen concentration nitrogen nutrient index 

分 类 号：S511[农业科学—作物学]