Non-destructive method for estimating cover-crop biomass

This study presents a non-destructive method for estimating cover-crop biomass, based on field estimation of soil cover and cover height. The estimation of biomass allows to quantify expected services offered by cover crops, such as competition against weed, erosion and leaching reduction, input of nutrients and organic matter. Linear models were adjusted to the data of a field screening of 20 cover crop species. The results show that the product of soil cover and height is a good predictor of cover-crop biomass. In addition, the use of a global model, adjusted to all species together, allows to predict the biomass produced in the context of another trial set up the year after, with different cropping conditions. The developed method is thus sufficiently robust to be used on field data, with a precision in biomass estimation of approx. 20 %. It also allows to estimate nutrient uptake by cover crops and assess the quantity of nutrients made available for the following crop.