Rapidly Estimating Nutrient Contents of Fattening Pig Manure from Floor Scrapings by near Infrared Reflectance Spectroscopy

Abstract

The objective of this study was to investigate the feasibility of near infrared (NIR) reflectance spectroscopy technology for rapid analysis of the nutrient content in fattening pig manure which was obtained from floor scrapings. Diverse samples ( n = 108) were collected. Samples were scanned from 12000 to 4000 cm−1 (833 to 2500 nm). The NIR calibration models of moisture, organic matter (OM), total nitrogen (TN), ammonium nitrogen (AN), total phosphorus (TP), total potassium (TK), magnesium (Mg), iron (Fe), copper (Cu) and zinc (Zn) were developed using the leave-one-out cross-validation procedure using partial least squares method. Results showed that NIR reflectance spectroscopy is a potentially usable method to determine moisture, OM, AN and TK. The calibrations for TN, Cu and Zn were found to be able to discriminate between high and low values. Although further efforts with larger data sets are needed to better determine the feasibility, limitations and requirements for developing accurate and robust calibrations for manure constituents using NIR reflectance spectroscopy, there are encouraging results to recommend NIR reflectance spectroscopy as a rapid instrument for on-site measurement of pig manure from floor scrapings.