Submitted to: Agronomy Journal
Publication Type: Review Article
Publication Acceptance Date: August 3, 2007
Publication Date: May 1, 2008
Citation: Hatfield, J.L., Gitelson, A.A., Schepers, J.S., Walthall, C.L. 2008. Remote Sensing of Agronomic Parameters: Scientific Advances. Agronomy Journal. 100:S117-S131. Technical Abstract: Remote sensing has provided valuable insights into agronomic management over the past 40 years. The contributions of individuals to the development of remote sensing methods have led to understanding of how leaf reflectance and leaf emittance changes in response to leaf thickness, species, canopy shape, leaf age, nutrient status, and water status. Leaf chlorophyll and the preferential absorption of different wavelengths provides the basis for utilizing reflectance as a tool using either broad-band radiometers typical of current satellite platforms or hyperspectral sensors that measure narrow wavebands. The basic understanding of leaf reflectance has led to the development of various vegetative indices that have been extended to crop canopies that have been used to quantify various agronomic parameters, e.g., leaf area, crop cover, biomass, crop type, nutrient status, and yield. Emittance from crop canopies is a measure of leaf temperature and the development of infrared thermometers have fostered the development of various crop stress indices that are currently used to quantify water requirements. These tools are still being developed as we learn more about how to use the information provided in reflectance and emittance measurements with a range of different sensors. Remote sensing continues to evolve as a valuable agronomic tool that provides information to scientists, consultants, and producers about the status of their crops. This area is still relatively new compared to other agronomic fields; however, the information content is providing valuable insights into improved management decisions.