On-Site assessment of corn silage biochemical methane potential using a cost-effective NIR device

Corn silage, widely used as a feedstock in anaerobic digestion systems, plays a significant role in renewable energy production. The measurement of the biochemical methane potential (BMP) of ensiled corn at the farm level is of utmost importance for characterizing its methane production potential and optimizing biogas generation. Thus, understanding the BMP of corn silage from individual farms is crucial for efficient biogas plant management and proper utilization of this valuable resource. The study aimed to assess the BMP of corn silage using a cost-effective miniaturized handheld NIR spectrometer with minimal sample preparation. Twenty-nine corn silage wet samples from as many dairy farms located in Lombardy (Northern Italy) were used. NIR calibrations were developed by means of partial least-square (PLS) regression obtaining models with a fairly good coefficient of determination (R2C = 0.92 and R2CV = 0.80 for DM and R2C = 0.90 and R2CV = 0.75 for BMP) and a reasonable prediction error (RMSECV = 1.38 and 4.76 for DM and BMP, respectively). Based on these results, the handheld spectrometer would be useful for providing a fast screening of dry matter (DM) and biochemical methane potential (BMP) in corn silage wet samples at farm level, enabling proper management of biogas plants and rapid turnaround in farm advisory systems.