摘要
为探明施氮量对宁夏引黄灌区覆膜滴灌玉米根长密度(RLD)的影响,设置5个施氮水平和1个对照(CK,不施氮与不覆膜)进行试验,测定玉米RLD,建立不同施氮量下相对根长密度(NRLD)模型,并加以检验。结果表明:不同施氮处理的玉米RLD分布区域均随土层深度的增加而减小,且大部分集中在0~20 cm土层;随着施氮量的增加,RLD分布区域明显扩大;NRLD分布满足三阶多项式函数模型,模拟曲线的决定系数R2为0.951,模型检验结果R2为0.845,均方根误差(RMSE)为0.248,拟合效果好,但该多项式模型不能保证NRLD在相对取样深度Zr为1时达到0,故对玉米NRLD分布多项式模型进行优化。优化模型验证结果显示,各施氮处理RMSE不大于0.308,CK、N0、N1、N2、N3和N4处理的标准化均方根误差分别为0.242、0.193、0.184、0.226、0.208和0.273,R2分别为0.903、0.953、0.920、0.944、0.962和0.898,具有较高的拟合度,解决了NRLD在Zr=1时达到0的问题。本研究可为宁夏引黄灌区膜下滴灌玉米NRLD分布拟合、根系养分吸收和施肥管理提供理论参考。
The objective was to establish the root length density(RLD)distribution relation model of maize at different nitrogen rates,and explore the effects on RLD of maize under drip-irrigation with plastic film in Ningxia.The relationship was improved between the spatial distribution characteristics of maize root system and nitrogen absorption.The interaction was promoted between maize root and soil.The nitrogen fertilizer application rate of maize was optimized under the condition of water and fertilizer integration.There were five nitrogen fertilizer application rates and the treatment of no application of N fertilizer and no mulching as control(CK)in this experiment.The experiment plot was in farm of Pingjibao which was located in Yinchuan City,Ningxia,Northwest China.The RLD of drip irrigated maize was measured.The model of relative root length density(NRLD)was established and verified at different N application rates.The results showed that the RLD distribution of drip-irrigation maize was decreased with the increase of depth of soil layer in the N fertilization treatment.The vertical distribution of root length in the 0~20 cm soil layer was the largest.The RLD distribution range of maize was expanded significantly with the increase of N fertilizer application rate.The NRLD value of maize in all treatments were consistent with cubic polynomial function.The determination coefficient of simulation curve was 0.951.The results of the evaluation showed that determination coefficient of linear relationship between simulated and observed values of NRLD was 0.845,and the root mean square error(RMSE)was 0.248.The fitting result of cubic polynomial function had a good effect.But it should be noted that the polynomial model could not guarantee that the value of NRLD reached zero at the Zr was equal to 1.Therefore,the cubic polynomial model of NRLD maize was optimized and verified.The verification results of the optimized model showed that RMSE in all nitrogen treatments was not more than 0.308,the standardized root mean squar
作者
贾彪
李振洲
王锐
孙权
王掌军
刘根红
JIA Biao;LI Zhenzhou;WANG Rui;SUN Quan;WANG Zhangjun;LIU Genhong(School of Agriculture, Ningxia University, Yinchuan 750021, China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2020年第9期266-273,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
宁夏回族自治区自然科学基金项目(2020AAC02012)
宁夏回族自治区重点研发计划项目(2019BBF03009、2018BBF02004)
国家自然科学基金项目(31560339)
宁夏大学草学一流学科建设项目(NXYLXK2017A01)
西夏区科技局科技项目(2018XXKJ01)。
关键词
玉米
膜下滴灌
相对根长密度
空间分布
多项式函数
模型优化
maize
drip irrigation under plastic film
normalized root length density
spatial distribution
polynomial function
model optimization
