Using CropSyst to Evaluate Biochar as a Soil Amendment for Crops

This report uses the CropSyst simulation model to examine how biochar could affect potato production in loamy sand soil near Moses Lake, Washington. Researchers simulated two types of biochar, two application rates, and full, deficit, and no-irrigation conditions using 30 years of weather data. Biochar produced essentially no yield benefit under full irrigation and projected gains of approximately 4% when water limited crop growth. These small gains required biochar application rates substantially higher than those normally reported, making their economic value uncertain. Biochar’s ability to adsorb ammonium did not reduce nitrogen leaching because ammonium was converted relatively quickly to mobile nitrate. Biochar also produced a slight increase in simulated nitrous oxide emissions. The results suggest that biochar may offer more potential for water-limited dryland crops than for fully irrigated crops, although field variability could obscure the relatively small benefits projected by the model.