Modeling Dynamic Soil Properties Under Long-Term Bioenergy Crop Management Using Apex.

Corn (Zea mays L.) stover is an attractive source of feedstock to the bioenergy industry.  The amount of stover left in the field, however, is a critical sustainability factor for grain production and other ecosystem services (e.g. reducing erosion-related sediment and nutrient losses, soil carbon sequestration).  The National Cooperative Soil Survey (NCSS) recognizes the need to provide enhanced information about soil change in response to land management and climate change.  This study is one of many studies to collect and aggregate dynamic soil properties (DSPs), coupling a long-term empirical dataset with predictive modeling. Soil, crop, and climate data collected between 1998 and 2014 from an USDA-ARS long-term bioenergy site in Ithaca, NE will be used to calibrate and validate the Agricultural Policy Environmental eXtender (APEX) model, a comprehensive process-based model (water, plant growth, nutrient cycling, hydrology, soil erosion, soil moisture, tillage, and plant environment control). Upon validation, APEX will be used to populate DSPs under different corn stover removal rates for soil survey.