Prediction of the clover content of red clover- and white clover-grass mixtures by near-infrared reflectance spectroscopy

abonos abonos nitrogenados application rates botanical composition composition botanique dose d'application engrais espectrometria fertilizers gramineae measurement mesure methode methodology methods nitrogen fertilizers poaceae reflectance reflectancia spectrometrie spectrometry spectroscopy trifolium trifolium pratense trifolium repens