Quantitative Approaches for Using Color Infrared Photography for Assessing In-Season Nitrogen Status in Winter Wheat

摘要: Due to the timing and rates of N applications in wheat (Triticum aestivum L.), potential exists for high loading environment. Plant tissue tests offer growers ability determine in-season status, optimize use efficiency. However, sampling analysis can be costly, difficult, time consuming. Remote sensing may a solution these problems. The objectives this study were (i) if remote could used estimate (ii) within-field calibration would improve crop (iii) optimum estimated using sensing. Research was conducted 1999 2001 at eight sites. Two sites had randomized complete block designs with variety, seeding rate, rate as treatments. Six single variety. Biomass found influence spectral measurements status. A strong relationship between normalized difference vegetation index (NDVI) growth stage (GS)-30 whole-plant concentration (R 2 = 0.69) GS-30 uptake 0.61) found. Within-field did not estimation status by NDVI. While it possible NDVI uptake, predicted fertilizer based on highly unreliable. reliably that mean biomass values >1000 kg ha -1 .