Different crop types require variable resources for production, have diverse economic and nutritional values, and play distinct roles in national food security. This observation applies to all agricultural products, including livestock. Therefore, changes in crop mix in domestic production and trade affect the environmental, economic, and social performance of agriculture production. While much modeling work has been devoted to spatial heterogeneity of crop production, few have quantified the distinctions among crop types.
Employing the SAM database, we develop a SAM-CMT (crop mix and trade) model to assess agricultural sustainability in environmental, economic, and social dimensions with a given crop mix. We develop a case study of China’s potential trade retaliation on US agriculture to investigate the impacts of trade policies on agricultural sustainability. Employing a global scale computable general equilibrium model — Global Trade Analysis Project (GTAP), we are able to get the crop mix with a trade policy shock. Figure below illustrates the framework of this application: we first impose a 25% positive shock on the US-China agricultural tariffs and obtain the crop mix and trade portfolios; then we apply these portfolios to our SAM system and get the new SAM scores for each indicator; in the end, we compare each SAM indicator’s values before and after the tariff shocks.

The framework for using GTAP simulated scenarios to assess performance changes in sustainable agriculture
This recently published paper demonstrates the use of the SAM-CMT model.