Use of near infrared reflectance spectroscopy for the determination of silica content in tall fescue

摘要

Major disadvantages of using tall fescue as forage grass are its low digestibility and animal voluntary intake. One of the factors explaining this is the high silica content of tall fescue in comparison with other forage grass species. Therefore, we evaluated the possibility to use NIRS on grass samples to predict the silica content. In 2014, we collected 297 samples on four different trials with tall fescue. These samples were analysed by wet chemistry for silica content, the NIRS spectra were recorded and a calibration model was built. In 2015, forage samples of 25 genotypes in a breeding nursery were collected and used for validation of the calibration equation. The mean silica content in this sample was 0.56% with a standard deviation of 0.14%.The validation statistics indicated that prediction of the silica content for this independent validation sample was good (SEP 0.063%; R2= 82.2%). The large variation in silica content found within the tall fescue genotypes and the ease of prediction using NIRS are a good basis for selecting tall fescue varieties with lower silica content.