The objective is to develop remote sensing methods to estimate forage nutrition and yield in the field in Northern Sweden. Field and lab measurements on grass-legume mixtures will be conducted from June 2018 to December 2019. At sampling time, drones flight with multispectral cameras, hyper-spectral reflectance measurement (e.g. with Yara N-sensor), and an ultrasonic sensor, will be conducted in order to build prediction models for forage nutrition and yield. The project will develop models for estimating forage digestibility based on a small number (e.g. red, red-edge and NIR) of wavelengths, thus enabling the use of lighter and cheaper technologies that could be mounted on a drone or even on a smart phone. After models are developed at point scale, data from the drone flights can be used to produce a field map of real-time crop growth and nutritional status. Models developed with the Yara N-sensor can be directly used with a commercialized tractor-mounted sensor.