We have used a regional climate model to simulate the response of a crop to the hydrological cycle on a regional basis in one-way coupling. Results indicated that soil wetness, and thus evapotranspiration, can both enhance and suppress convective precipitation depending on the atmospheric thermal and dynamic conditions. An experiment with hypothetical crop over the entire US revealed enhancement of the hydrological cycle and slight rainfall increase in dry western US and moderate decrease in central US. We now extend this procedure to include two-way coupling and multiple crop models. This procedure allows for crop growth and development through the growing season with both above ground and below ground changes in mechanisms for regulating hydrological processes across the interface. Sensitivity tests are used to identify critical factors in the coupling process under high spatial and temporal resolution and improved sub-grid land use specification. The coupled model is tested by comparing model-generated values for biomass accumulation and final crop yield with observed quantities for the specific years being simulated.