Utilization of Remote Sensing to Monitor and Assess Agricultural Systems.

Remote sensing has been used to assess various components of agricultural systems for several decades. Utilization of different wavebands in various combinations to form vegetative indices have been used to estimate ground cover, biomass, leaf chlorophyll content, light interception, leaf area index, net primary productivity, and yield. There has been an evolution of vegetative indices over time; however, many of the applications used today are the same as those developed over 40 years ago. Development of new vegetative indices has not occurred because of the continued use of more familiar indices; however, there has not been a critical analysis of many of the vegetative indices and what they represent in terms of the biophysical properties of crop canopies. To continue to construct a platform using remote sensing will require we begin to understand how different wavebands can be related to crop canopy development and growth and how these data can be fused with other spectral wavebands, e.g., thermal infrared, synthetic aperature radar, or microwave. Combinations of wavebands can be used to estimate phenology of crops, crop stress, crop water use rates, and changes in crop growth with sufficient temporal and spatial resolution to allow for a quantitative assessment of field variation. The potential for increasing the impact of remote sensing to use in agricultural decision making exists and we need to realize how to develop and transfer this information to decision makers in a timely manner.