A review of near infrared spectroscopy in the analysis of livestock and poultry manure and compost in China

China has abundant livestock and poultry manure. With the development of large-scaled manure composting as fertilizer, it becomes more and more important to rapidly analyze the material and compost on line. Because of several advantages such as rapidness, non-destructivity, stabilization and high efficiency, near infrared spectroscopy (NIRS) has been applied in many fields, such as industry, agriculture and pharmaceuticals in recent years. Literatures of studies on the analysis technique of NIRS applied to livestock and poultry manure and compost were surveyed. The results show that NIRS may be a good technique applied to quantitatively analyze many physicochemical characteristics such as moisture, organic matter, macro-elements and so on in livestock and poultry manure and compost. However, further research is needed in the following areas: analysis of the mechanism, improvement of NIRS models using new chemometric tools, standard methods for online analysis and corollary equipments, upgrade and maintenance of models and resource sharing by the whole society through internet.