Satellite and field radiometry for the estimation of biomass production in a grassland site in state of Durango, Mexico

The accurate and rapid estimation of biomass is important for the management of rangelands. The objective of this study was to find regression models to predict aerial biomass at a grassland site in the state of Durango, Mexico. For this purpose, samples of above ground biomass and normalized difference vegetation index values were obtained from two sources (NDVI-field radiometer and NDVI-MODIS) during the growing season of 2011 and 2013. Using 2011 data (n=180), the model Ln (Y) = beta(0) + beta X-1 +beta X-2(2) was found with the NDVI-field radiometer, R-2 = 0.54, and Y-Lambda 0.3 = beta(0) + beta X-1 + beta X-2(2) with NDVI-MODIS, R-2 = 0.81. Model validations were carried out comparing regression coefficients of 2011 and 2013 models, there was not significant difference with t (P>0.05). However, model with NDVI-MODIS had 77 outliers; therefore any prediction must be considered cautiously.