Landscape configuration is an important predictor of sunflower yield in the Argentinean Pampas Region

Abstract

Conventional agriculture is frequently associated with large-scale environmental degradation and landscape homogenization. In contrast, ecological intensification incorporates natural habitat conservation and landscape complexity to improve important ecosystem services such as pollination and crop yields. In an observational study of 105 fields in the Argentinean Pampas Region, we explored whether sunflower yields were related to landscape composition (percentage of natural habitat) and configuration (field size and edge density), and covariates of agricultural management practices such as nitrogen fertilizer addition, seed density, sowing date and crop cultivar. Our mixed-effects models revealed that field size and edge densities between crop and natural habitat are important predictors of yield. For example, a doubling of edge density from 40 m/ha to 80 m/ha predicted an 11.3% (269 kg/ha) yield increase, while a doubling in the field size from 40 ha to 80 ha predicted a 6.1% (149 kg/ha) yield decrease. We suggest that pollination is an important driver of both effects as higher edge densities and smaller field sizes reduce wild pollinator flight distances to crop flowers and thus increases the chances for effective crop pollination. This study provides key information for sustainable management of sunflower agroecosystems.