Agronomic and Stream Nitrate Load Responses to Incentives for Bioenergy Crop Cultivation and Reductions of Carbon Emissions and Fertilizer Use

Abstract

AbstractExcessive nitrate loads in surface waters are a major cause of hypoxia and eutrophication. In many places, agriculture is the single largest source of nitrogen entering receiving waters. Perennial energy grass crops have the potential to reduce nitrogen loads from agricultural areas, while sequestering carbon and offering new economic opportunities for farmers. This study analyzes farm system-scale cropping and fertilizer application decisions, and resulting nitrate loads, as driven by prices for the bioenergy crop miscanthus, as well as investigates reductions of carbon and other greenhouse gas emissions and nitrogen fertilizer use. An economic model of farm-system-scale decisions is coupled to a hydrologic-agronomic model of the physical stream system to obtain nitrate loading and crop yield results for varying combinations of prices and policies for a typical Midwestern agricultural watershed. For the scenarios examined, a large reduction in stream nitrate load depends on a high price for misca...