Author:

Keywords:

manure, spectroscopy, NIR, reflectance, rapid, analysis

Abstract:

Hog manure is a heterogeneous suspension of solid particles (dug) in a liquid matrix (urine), which tends to separate during storage. Therefore, rapid analysis at haul-out time is necessary to obtain a good nutrient management using manure. In this study, the effectiveness of near-infrared (NIR) technology for rapid, on-site analysis of the nutrient content in hog manure was evaluated. A Zeiss Corona 1.7 VISNIR diode array instrument with an OMK measuring head, was calibrated against wet chemistry data using 169 diverse hog manure samples collected from farms in the northern part of Belgium. Dry matter content (DM), organic matter content (OM), total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH4-N), total phosphorous (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg) and pH were measured. Correlation coefficients (r) between predicted and measured concentration values ranged from 0.367 for pH to 0.834 for K. Ratios of data range to standard error of prediction (SEP) varied from 6.6 for Na to 10.3 for TKN. Based on the individual correlation coefficients and ratios we conclude that NIR techniques will allow us to make valuable quantitative predictions for total N, NH4-N, K and OM, and approximate predictions for DM, Ca, P and Mg. However, prediction of Na and pH requires further investigation. Mounting this diode array instrument on a slurry tanker might enable environmentally and economically sound nutrient management.