New applications of near-infrared spectroscopy in crop and soil analysis
Farmers and ranchers send soil and crop samples to commercial laboratories for chemical tests that measure nutrient concentrations as well as protein, fiber, and carbohydrates that influence the nutritional quality of feed. These tests, however, can be time consuming, and some require special equipment and extremely clean conditions.
Near-infrared spectroscopy (NIRS), an analytical technique used for plant, animal, and soil analysis, provides faster and cheaper results, reducing laboratory costs as much as 80%. This method correlates light reflected from a sample with laboratory measurements of carbon, nitrogen, phosphorus, protein, fiber, or carbohydrate concentrations, among other tests. If the target parameter of a new sample falls within the set used for calibration, NIRS correlations can be applied to different spectrometers as well as samples collected from different regions, states, and countries.
Two recent journal articles extend near-infrared spectroscopy to new applications in crop and soil analysis: one in Crop Science estimates the ratio of alfalfa and grass in forage gathered in the northeastern United States, and the other, in the Journal of Environmental Quality, estimates plant-available phosphorus in soil collected around the Chinese countryside.'