中国生态农业学报2016，Vol.24Issue(10)：1339-1346,8.DOI:10.13930/j.cnki.cjea.160182
硝酸盐反射仪和 SPAD 法对玉米氮素营养诊断的比较
Comparison of RQ flex and SPAD methods of diagnosing maize (Zea mays) nitrogen nutrient
摘要
Abstract
Precise and prompt approach of crop nutrient diagnosis is the prerequisite in determining crop N content and the recommendation of reasonable amount of N fertilizer. In this study, a field experiment was carried out under drip irrigation condition, the chlorophyll equipment (SPAD-502 Plus) and nitrate reflectrometer (RQ flex10) was employed in terms of diagnosis of maize N nutrition during key growth stages. The aim of the study was to build maize fertilization mode by using the most suitable diagnosis approach. Five N fertilizer application rates were arrayed, including N0 [0 kg(N)·hm-2], N225 [225 kg(N)·hm-2], N330 [330 kg(N)·hm-2], N435 [435 kg(N)·hm-2] and N540 [540 kg(N)·hm-2]. The difference of diagnostic effect between SPAD-502 Plus and RQ flex10 methods on maize plant N nutrient were compared based on correlation analysis. The analysis compared the relationships between corn leaf SPAD and leaf sheath NO3- concentration for various N fertilizer application rates, plant total N content and yield during different maize growth stages. Also the sensitivities of the RQ flex 10 and SPAD methods of diagnosis of maize plant N nutrient were compared. The results were as follows: 1) Maize leaf SPAD and leaf sheath NO3- concentration significantly increased with increasing N fertilizer application rate and the most sensitive period was from jointing stage to either tassel-emergence stage or grain-filling stage. The response of sheath NO3-concentration to N application rate was more sensitive than that of SPAD. This resulted into a higher degree of fit between NO3-concentration determined by RQ flex 10 method and N application rate or maize yield. RQ flex 10 method was more sensitive in diagnosis of maize N nutrition. 2) The total N content in maize had a significant linear correlation with leaf SPAD, while there was linear and then a constant correlation between the total N and sheath NO3- concentration. That was, total N content was linearly correlated with NO3- concentration as corn sheath NO3- concentration less than 186 mg·L-1, however, total N content varied slight when sheath NO3- concentration exceeding 186 mg·L-1. 3) The recommended economic fertilizer application rate in maize under drip irrigation was 402.5 kg·hm-2, which produced a yield of 17 049 kg·hm-2. The critical NO3-concentration was 729.3 mg·L-1 at jointing stage, 536 mg·L-1 at tassel emergence stage and 81.2 mg·L-1 at grouting stage, respectively. In conclusion, our study showed that both the chlorophyll meter and RQ flex 10 were suitable for maize N nutrient diagnosis. Moreover, the RQ flex 10 approach was a more sensitive method than the chlorophyll meter in diagnosing maize N nutrient status. The study suggested that the RQ flex method was highly suitable for the recommendation of N fertilizer as well as better N resource management in maize fields.关键词
施氮量/玉米/氮素营养/硝酸盐反射仪/叶绿素仪/SPAD值/叶鞘NO3含量/营养诊断Key words
N application rate/Maize/Nitrogen nutrient/Nitrate reflectrometer/Chlorophyll meter/SPAD reading/Sheath NO3 concentration/Nutrient diagnosis分类
农业科技引用本文复制引用
夏文豪,刘涛,关钰,王进,褚贵新..硝酸盐反射仪和 SPAD 法对玉米氮素营养诊断的比较[J].中国生态农业学报,2016,24(10):1339-1346,8.基金项目
国家“十二五”科技支撑项目(2012BAD42B02)资助@@@@* The study was funded by the National Key Technologies R&D Program of China (2012BAD42B02) （2012BAD42B02）
