Effects of management practices on crop yields in the conterminous United States

Abstract:

Crop yield has and will be affected by environmental conditions, such as climate change and variability, and atmospheric carbon dioxide concentration [CO₂]. In addition to mean climate changes, extreme weather events such as heatwaves and droughts have been increasingly affecting crop yields. To manage the adverse impacts of environmental conditions on crop yields, agricultural management practices, for example, intensification and extensification of irrigation and fertilizer application are considered as climate adaptation options that alleviate the water and nutrient stress on crop growth.

In this study, we simulate crop yield in the conterminous United States (CONUS) using Integrated Science Assessment Model (ISAM) at 0.1-degree resolution based on newly developed historical and future data of land use and land cover changes (LULCCs), soil, [CO₂], climate variables (e.g., temperature and precipitation), N deposition, and management practices (e.g., irrigation and N fertilizer). We focus on three major crops, maize, soybean, and wheat, that account for most of the crop production especially in the CONUS. We investigate the extent to which changes in management conditions (e.g. irrigation, fertilization, sowing date, planting density) benefit the crop yield under current and future climate and weather related extreme events. Our modeling framework provides the path for stakeholder participation to increase the understanding of how climate and weather extremes impacts food and water systems of the CONUS.