Abstract The present study developed a method to use RapidEye satellite information for N management in durum wheat cultivation. The estimation of the N status was based on the development of Nitrogen Nutrition Index (NNI), referred to as the ratio between actual N concentration (Nac) and the minimum N content required to obtain maximum biomass (critical N concentration (Nc)). Nc was then calculated by means of a Nc dilution curve, which was calibrated through the use of durum wheat experimental fields (the number varying per year) in Val D’Orcia area (Tuscany) over three consecutive growing seasons from 2009/2010 to 2011/2012, respectively. The data (Nac and biomass) to produce estimated NNI were obtained by matching the available field samples with information obtained from remote sensing. Statistical analysis indicated that both modified chlorophyll absorption in reflectance index (MCARI) and enhanced vegetation index (EVI2) were the best vegetation indices (VIs) for estimating Nac and biomass, respectively. The validation, attained using the 2012/2013 experimental field data, showed that the proposed model was very reliable. This could be an effective method in advising farmers on the application of midseason N fertilization treatments, through precision farming operations.

中文翻译：

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将卫星数据与氮营养曲线相结合，用于硬质小麦的精确追肥施肥

摘要 本研究开发了一种利用 RapidEye 卫星信息在硬粒小麦种植中进行氮管理的方法。氮状态的估计基于氮营养指数 (NNI) 的发展，即实际氮浓度 (Nac) 与获得最大生物量所需的最小氮含量（临界氮浓度 (Nc)）之间的比率。然后通过 Nc 稀释曲线计算 Nc，该曲线通过使用 2009/2010 至 2011 年连续三个生长季节在 Val D'Orcia 地区（托斯卡纳）的硬粒小麦试验田（每年变化的数量）进行校准/2012 年。产生估计 NNI 的数据（Nac 和生物量）是通过将可用的现场样本与从遥感获得的信息进行匹配而获得的。统计分析表明，修正叶绿素吸收反射指数 (MCARI) 和增强植被指数 (EVI2) 分别是估算 Nac 和生物量的最佳植被指数 (VI)。使用 2012/2013 年实验现场数据获得的验证表明，所提出的模型非常可靠。这可能是一种有效的方法，可以通过精准农业操作向农民建议使用季中氮肥处理。