Application in analysis of soils

Although near-infrared (NIR) spectroscopy has been used in the research laboratory for the compositional analysis of soil, its importance to day-to-day agriculture and land use is just emerging. This chapter presents an overview of results from the use of NIR spectroscopy to predict various constituents, properties, and functions in soil. The time- and cost-savings potentials of NIR spectroscopy alone encourage the exploration of many new applications of the technology to soil. Most of the application of NIR spectroscopy to soil analysis to date attempts to replace a conventional soil test on dried samples with more rapid, cost-effective NIR prediction. The method of soil sampling can significantly affect the reflectance spectrum of the soil. The reliability of the reference analysis is highly dependent on the completeness of the mixing of the sample.