%0 Journal Article
%T Diagnosis of the state of N in wheat via digital image processing technique<br>数字图像诊断技术在冬小麦氮素营养诊断中的应用
%A ZHANG Li-Zhou
%A HOU Xiao-Yu
%A ZHANG Yu-Ming
%A LI Hong-Jun
%A CHENG Yi-Song
%A HU Chun-Sheng
%A <br>张立周
%A 侯晓宇
%A 张玉铭
%A 李红军
%A 程一松
%A 胡春胜
%J 中国生态农业学报
%D 2011
%I 
%X This study used digital image acquisition via digital camera and analysis method in combination with rapid soil and plant N test to diagnose the state of N in wheat crops and recommend N fertilization modes in wheat fields. The relationship between color parameters and N nutrient indices was analyzed and the possibility of using digital image analysis method to diagnose the state of plant N evaluated. Then a standard method for digital image acquisition and application in plant N diagnosis was established. The best mode for diagnosing the state of plant N via digital image analysis method was also determined. The study further established a N diagnosis index system and an equation for recommending N application. The result indicated that digital image processing technique was usable in detecting the N state in winter wheat. The best angle between digital camera and wheat canopy in the field was 30°~60°. Significant correlations were noted among color parameters and N application rate, SPAD, plant nitrate content, plant total N content and nitrate contents in the 0~90 cm soil depth at wheat jointing and booting stages. Compared with other plant canopy color parameters, normalized greenness intensity (NGI), calculated as G/(R+G+B), was much better as it produced better correlations with plant total N, SPAD, nitrate content and soil nitrate content at jointing stage. While NGI was the best diagnosis index, jointing was the key diagnosis stage of the state of N in winter wheat crops.
%K Winter wheat
%K Digital image
%K Color parameter
%K Nitrogen state diagnosis
%K Growth stage<br>冬小麦
%K 数字图像
%K 色彩参数
%K 氮素营养诊断
%K 生长时期
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=03F54A49DE00578AA0E5DDF5BC021AA7&cid=1A8B5357F0EF07B8&jid=AB3ABF502E2E1FF39F0E3B80164C9031&aid=8EC741CE2A43A15BDCE6C7C7FFEF0E96&yid=9377ED8094509821&vid=2A8D03AD8076A2E3&iid=94C357A881DFC066&sid=C4690645D4CCDCE7&eid=CA21EE48F5BB8E19&journal_id=1671-3990&journal_name=中国生态农业学报&referenced_num=0&reference_num=22