A Near Infra?Red Reflectance Spectrophotometer was calibrated to analyse Italian ryegrass for protein nitrogen (N). Rye?grass samples having a wide range in N content were analysed by standard ?wet? chemistry techniques and the resulting data used to calibrate the Near Infra?Red Spectrophotometer for ryegrass N analysis. A correlation (r) of 0,99 and standard error of calibration (SEC) of 0,209 resulted from the initial regression analysis between the Near Infra?Red Spectroscopy (NIRS) estimated and ?wet? chemistry data. In order to further evaluate the accuracy of the NIRS calibration a separate set of ryegrass samples were analysed for N content, by both the ?wet? chemistry and NIRS methods, resulting in a correlation (r) of 0,98 and standard error of prediction (SEP) of 0,235. The applicability of the NIRS ryegrass calibration to other species was briefly examined by estimating the N contents of kikuyu (Pennisetum clandestinum) (r = 0,97 and SEP = 0,277).
Journal articles from the Grassland Society of Southern Africa (GSSA) African Journal of Range and Forage Science as well as related articles and reports from throughout the southern African region.