Estimation of Nondestructive Rice Leaf Nitrogen Content Using Ground Optical Sensors

摘要: Ground-based optical sensing over the crop canopy provides information on mass of plant body which reflects light, as well nitrogen content is closely related to greenness leaves. This method has merits being non-destructive real-time based, and thus can be conveniently used for decision making application fertilizers crops standing in fields. In present study relationships among leaf rice canopy, growth status, Normalized Difference Vegetation Index (NDVI) values were investigated. We measured Green normalized difference vegetation index() NDVI() by using two different active sensors (Greenseeker, NTech Inc. USA). The was conducted years 2005-06 during growing season at experimental plots National Institute Agricultural Science Technology located Suwon, Korea. experiments carried out with randomized complete block design four levels (0, 70, 100, 130kg N/ha) same amount phosphorous potassium fertilizers. gNDVI rNDVI increased advanced reached maximum around early August, G(NDVI) a decrease observed maturation. highly correlated July 2005 2006. On basis this finding we attempted estimate N contents data obtained determination coefficients linear model 2006 0.88 0.94, respectively. estimated showed good agreement (). Results from show that represent significant positive correlation before panicle formation stage. appeared very effective parameter canopy.