Authors

Abstract

The cost-benefit of riparian buffers to landowners has not been fully understood despite its ecosystem benefits. This study investigates the environmental and economic value of multi-purpose buffers for biomass production under alternative land-management scenarios at the watershed scale. The work incorporates the Soil and Water Assessment Tool with a field-scale tool, the Agriculture Conservation Practice Framework, and cost-benefit analysis. Our work took place in the agriculturally dominant Raccoon River watershed (RRW) in Iowa. The cost analysis includes implementing and harvesting the switchgrass buffers, the value of nitrogen and phosphorus fertilizer, and the forgone income of cropland to determine the net return under 12 alternative feedstock scenarios. We estimated that 14 603 Mg of nitrogen and 2563 Mg of phosphorus runoffs can be intercepted by riparian buffers in the RRW, representing a nutrient loss reduction of 11% of nitrogen and 26% of phosphorus. These nutrients are valued at $1.31 million (M) for phosphorus and $1.24 M for nitrogen as fertilizers. The trapped nutrients account for 12% of the riparian buffers total cost. We found that net economic returns increase with biomass market price, increase with maintenance fertilizer application, and decrease with the cropland areas that are converted to buffers. Under current land management, a biomass market price at $60 per dry ton of biomass would be economically viable at the sub-basin level when maintenance fertilizers are applied. At $80 per dry ton, all 108 sub-basins in the RRW would be profitable up to $517 a year. The results highlight the trade-offs between water quality and profitability. Published 2021. This article is a U.S. Government work and is inthe public domain in the USA.