Environmental Science Archives (2025) Vol. IV Issue 1 DOI: 10.5281/zenodo.14698729 59 www.envsciarch.com Hyperspectral Imaging Assisted Evaluation of Diverse Crop Residue and Nitrogen Management Practices in Wheat Crop Vicky Singh 1 , RK Gupta 1 , Seema Sepat 2 and Mehra S Sidhu 3 * 1 Department of Soil Science, Punjab Agricultural University, Ludhiana - 141004, India 2 Indian Institute of Maize Research, Ludhiana - 141004, India 3 Electron Microscopy and Nanoscience Lab, Directorate of Research, Punjab Agricultural University, Ludhiana – 141004, India *Correspondence for materials should be addressed to MSS (email: sidhums@pau.edu) Abstract The study reports our evaluation of high resolution, hyperspectral leaf reflectance and pigment measurement as a potential tool to aid in identifying and delineating the effect of crop residue management and macronutrients on chlorophyll content and crop health of wheat crop (T. aestivum). The split–plot design was employed for the experiment with rice straw management practice as the main plots, while 4 sub treatments include an increase in N % from 23 % to 50 % compared to the control. Hyperspectral reflectance data (350-1000 nm) at 5 nm resolution were collected after 2nd irrigation and N % dose application at about 85 days of crop maturity using a SPECIM camera under natural light conditions from ~1200-1500 hrs. The reflectance was measured at ~60 cm from the plant tip and the variance and multivariate mean separation among the various treatments. There was a significant increase (~1.5 fold) in reflectance for the T4 treatment compared to the control (T1), and a corresponding increase in chlorophyll content was observed with the T4 treatment compared to the control. The increase in chlorophyll was also correlated with the content of mineral N soil (mg/kg). With the addition of additional N % along with residue- managed plots, there is a linear increase in chlorophyll content, which is also compared with SPAD and green seeker (NDVI) data taken simultaneously at the time of HSI imaging. This is the first observation where the HSI technique is successfully employed to study the impact of crop residue management on crop health. Keywords: Crop Residue management; Hyperspectral Imaging; Canopy Reflectance; Wheat; Chlorophyll Introduction Wheat is grown in 13 per cent of the cropped area of India. Next to rice, wheat is an essential grain of India and is the staple food of millions of Indians, particularly in the northern and northwestern parts of the country. India is the second largest wheat producer after China, accounting for 14 % of the world's total wheat production (FAOSTAT, 2020). The Rice Wheat Cropping System (RWCS) is India's most widely adopted and practised on 11 million hectares. This system is prevalent in Indo Gangetic Plains (IGP) and is predominant in Uttar Pradesh, Punjab, Haryana, Bihar, West Bengal, Madhya Pradesh provinces etc. In India, wheat occupies an area of about 29.3 mha, with a total production of 103.6 mt and productivity of 3,533 kgha -1 (FAOSTAT, 2021). RWCS plays a crucial role in food security and, on the contrary, results in several leading problems, including the exhausting nutrient pool in soil, deteriorating soil health, groundwater depletion, escalating production cost, and lower availability of labour. Extensive crop residue burning causes environmental pollution, enhanced greenhouse gas emissions, climatic vulnerabilities, and herbicide resistance in weed species. These are few major threats to its sustainability (Dhanda et al., 2022). ENVIRONMENTAL SCIENCE ARCHIVES ISSN: 2583-5092 Volume IV Issue 1, 2025 RESEARCH PAPER OPEN ACCESS Received: 2024/12/22 Accepted: 2025/01/16 Published: 2025/01/20