水稻叶绿素计诊断追氮法研究

Nitrogen fertilizer application based on the diagnosis of nitrogen nutrition of rice plants ( Oryza sativa L ) using chlorophyll meter.

长期定位框栽试验结果表明，本地灌溉籼、粳稻分蘖盛期和幼穗分化期叶绿素计读数（ＳＰＡＤ值）与单位面积叶绿素含量、含氮量呈极显著正相关（ｐ＜０．０１）．ＳＰＡＤ值与产量关系可用二次多项式描述．籼稻分蘖盛期和幼穗分化期的标准ＳＰＡＤ值分别为４３．４和４４．３，粳稻分别为４５．５和４６．７．叶绿素计（ＳＰＡＤ－５０２）测定简易、快速，不受光照条件限制，对样品无破坏性．叶绿素计诊断追氮法可望作为亚热带地区灌溉水稻诊断追氮的实用方法．

There were highly significantly positive correlations ( p <0 01) between chlorophyll meter readings (SPAD values) and leaf area based chlorophyll content, nitrogen content of indica and japonica genotypes at midtillering(MT), panicle differentiation(PD) in the long term fertilizer pot experiment at the campus of former Zhejiang Agricultural University The relationship between grain yields and SPAD values at MT and PD could be described by quadratic regression equations The critical SPAD values calculated from the polynomial at MT and PD were 43 4 and 44 3 for the indica genotype, and 45 5, 46 7 for the japonica genotype respectively The chlorophyll meter (SPAD 502) provides a simple, quick, sunlight independent and nondestructive method to estimate leaf area based chlorophyll content and nitrogen content and could be used to predict the need for fertilizer N topdressing in intensive, irrigated rice systems in subtropical area