Author(s): Adwait Adwait; Ghanshyam Giri; Hitesh Upreti; Gopal Das Singhal
Linked Author(s): Gopal Das Singhal
Keywords: Unmanned Aerial Vehicle (UAV) Vegetation Indices (VI) Senescence Phenology Multispectral NDVI NDRE
Abstract: Wheat is one of the world's most important staple crops which serves as a primary food source. Assessing the health of wheat crops is crucial for maximizing yield and ensuring food security. Optical remote sensing is a reliable technique used for monitoring crop health and helps in the early identification of stress factors. In this study, Unmanned Aerial Vehicle (UAV) based multispectral remote sensing has been used to monitor the crop health and phenology pattern of wheat crops grown under varying fertilizer treatments. The experimental study was conducted in the arid region of Uttar Pradesh, India. The experimental setup consists of 9 field plots corresponding to 3 fertilizer treatments in which nitrogen fertilizer was supplied at different rates: 150 kg/ha (Plot 1), 120 kg/ha (Plot 2, recommended dosage in this region), and 90 kg/ha (Plot 3). Each treatment had three replications, and irrigation was supplied to all the treatments as 100% ETc (crop evapotranspiration) using the drip irrigation method. A series of UAV-based multispectral data was acquired during different growth stages of wheat to capture the spatio-temporal variability in wheat growth. The UAV data was processed using the Pix4D fields software package and vegetation indices such as Normalized Difference Vegetation Index (NDVI) and Normalized Difference Red-Edge Index (NDRE) were calculated to analyze the temporal variation in crop growth for the 3 fertilizer treatments. NDVI and NDRE attained the maximum value during the flowering stage. The peak NDVI and NDRE values obtained for Plots 1,2 & 3 were (0.84,0. 86 and 0.86) and (0.54,0. 56,0. 56) respectively. The senescence rate was calculated for all the plots using the VIs value of the flowering stage and dough stage. The senescence rate obtained as per NDVI and NDRE were (0.76,0. 85 & 1.05) % /day and (0.70,0. 75 & 0.95) % /day for Plot 1,2 & 3. Grain yield was almost the same in plots having an overdose and recommended dosage of fertilizer. Higher senescence rate in Plot 3 resulted in a substantial reduction in grain yield. These findings demonstrate how UAV multispectral camera can enhance crop monitoring and promote sustainable farming methods by providing accurate and timely evaluations.
Year: 2025