基于主动冠层光谱仪的莴苣生物量及氮素营养状况估测  

Estimating lettuce(Lactuca sativa L.)biomass and nitrogen status using an active canopy sensor

作　　者：纪荣婷 闵炬[2] 王远 陆志新[3] 路广[3] 施卫明[2] JI Rong-ting;MIN Ju;WANG Yuan;LU Zhi-xin;LU Guang;SHI Wei-ming(Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environment,Nanjing 210042,China;State Key Laboratory of Soil and Sustainable Agriculture,Nanjing Institute of Soil Science,Chinese Academy of Sciences,Nanjing,Jiangsu 210008,China;Yixing Vegetable Office,Yixing,Jiangsu 214206,China)

机构地区：[1]生态环境部南京环境科学研究所,江苏南京210042 [2]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,江苏南京210008 [3]宜兴市蔬菜办公室,江苏宜兴214206

出　　处：《植物营养与肥料学报》2021年第1期161-171,共11页Journal of Plant Nutrition and Fertilizers

基　　金：国家重点研发计划项目(2017YFD0800404);江苏省农业科技自主创新资金项目(CX(18)1005);山东省重大科技创新工程项目(2019JZZY010701)。

摘　　要：【目的】研究冠层光谱技术在蔬菜氮素营养诊断中应用的可行性和提高其准确性的方法,为推进蔬菜氮素营养管理与施肥推荐提供快速无损检测技术。【方法】以茎菜类蔬菜—莴苣(Lactuca sativa L.)为研究对象进行田间试验。设置5个化肥年施用梯度:0、108、162、216、270 kg/hm2,在莴苣幼苗期、莲座期、茎形成期和收获期,利用GreenSeeker冠层光谱仪获取冠层光谱特征值—植被归一化指数(NDVI)和比值植被指数(RVI),并测定植株生物量和含氮量。评估用生育期NDVI和RVI值预测蔬菜生物量和氮素营养的可行性与准确性,并验证用移栽天数校正提高全生育期光谱值预测精度的可行性。【结果】NDVI和RVI与莴苣地上部生物量(AGB)、根冠比(RTS)、植株吸氮量(PNU)和植株氮浓度(PNC)等指标间均存在显著相关关系,尤其以NDVI相关性更高。相关性分析结果表明,NDVI与AGB和PNU呈正相关,相关系数分别介于0.779~0.945和0.819~0.938;与RTS和PNC呈负相关,相关性系数介于–0.367~–0.844和–0.328~–0.732。对比不同时期,莲座期和茎形成期的NDVI值对莴苣生物量和氮素营养指标预测的准确性较高,对AGB、RTS、PNU和PNC预测准确性分别为0.76~0.92、0.37~0.71、0.77~0.88和0.34~0.54。利用两年NDVI值建立各时期莴苣生物量和氮素营养状况统一预测方程,莲座期方程最为准确,对AGB、RTS、PNU、PNC预测准确性分别为73%、48%、52%、31%。综合全生育预测方程,冠层光谱仪测定的NDVI值对莴苣生物量和氮素营养预测指标的准确性较高,基于NDVI值的AGB、RTS、PNU和PNC预测方程准确度分别为54%、43%、57%和26%。引入移栽天数(DAT)对该预测方程进行校正后,AGB、PNU和PNC预测方程的准确度分别提高至62%、71%和34%。【结论】基于冠层光谱仪测定的各生育期的植被归一化指数(NDVI)可准确预测莴苣的生物量和氮素营养状况,尤以莲座期的预测结果最为准【Objectives】Canopy sensors have been widely used for nitrogen nutrition diagnosis of cereal crops recently,however fewer in vegetable crops.We studied its accuracy in nitrogen nutrition and growth diagnosis during vegetable growth seasons and the path of improvement of the accuracy.【Methods】A field experiment was conducted with lettuce(Lactuca sativa L.),a popular winter vegetable in the Taihu Lake region,as tested crop materials.Five chemical N rates of 0,108,162,216,270 kg/hm^2 were applied.At the seedling,rosette,stem formation and harvest stages,the values of normalized difference vegetation index(NDVI)and the ratio vegetation index(RVI)were determined using GreenSeeker canopy sensor,and the biomass and N content of lettuces were analyzed at the same time.The applicability and predicting accuracy of biomass and N status by canopy sensor were verified.【Results】The NDVI and RVI values were significantly related to the aboveground biomass(AGB),root-shoot ratio(RTS),plant N uptake(PNU)and plant nitrogen concentration(PNC)during growth seasons of lettuce,and the NDVI measurements showed higher accuracy indeed.The NDVI values were positively correlated with AGB and PNU,with the coefficients ranged from 0.779 to 0.945 and 0.819 to 0.938,respectively,and negatively correlated with RTS and PNC with the correlation coefficient ranged from–0.367 to–0.844 and–0.328 to–0.732.At the four growth stages,the measured NDVI values at the rosette stage and the stem formation stage had higher prediction accuracy,and the prediction accuracy for AGB,RTS,PNU and PNC was 0.76 to 0.92,0.37 to 0.71,0.77 to 0.88 and 0.34 to 0.54,respectively.Using two-year sensor measurements to establish a unified prediction equation for lettuce biomass and nitrogen nutrition status in each growth stage,the rosette stage equation gave the most accurate prediction of AGB(73%),RTS(48%),PNU(52%)and PNC(31%).Based on the whole growth stage,s prediction equations,the NDVI had high prediction accuracy for AGB,RTS,PNU and PNC,with accurate

关 键 词：莴苣 冠层光谱仪 NDVI值 RVI值 氮素营养预测 

分 类 号：S636.2[农业科学—蔬菜学]