In this study, we assess the feasibility of using Fourier Transform Infrared Photoacoustic Spec-troscopy (FTIR-PAS) to predict macro- and micro-nutrients in a diverse set of manures anddigestates. Furthermore, the prediction capabilities of FTIR-PAS were assessed using a novel errortolerance-based interval method in view of the accuracy required for application in agriculturalpractices. Partial Least-Squares Regression (PLSR) was used to correlate the FTIR-PAS spectrawith nutrient contents. The prediction results were then assessed with conventional assessmentmethods (root mean square error (RMSE), coefficient of determination R2, and the ratio of pre-diction to deviation (RPD)). The results show the potential of FTIR-PAS to be used as a rapidanalysis technique, with promising prediction results (R2 > 0.91 and RPD >2.5) for all elementsexcept for bicarbonate-extractable P, K, and NH4+-N (0.8 < R2 < 0.9 and 2 < RPD <2.5). Theresults for nitrogen and phosphorus were further evaluated using the proposed error tolerance-based interval method. The probability of prediction for nitrogen within the allowed limit iscalculated to be 94.6 % and for phosphorus 83.8 %. The proposed error tolerance-based intervalmethod provides a better measure to decide if the FTIR-PAS in its current state could be used tomeet the required accuracy in agriculture for the quantification of nutrient content in manure anddigestate.