Agriculture

Loosely speaking, "critical" approaches to social science are perspectives that seek to achieve equality and justice or to criticize the opposite. They often focus on institutions, "structures," social and economic phenomena, or means of governance that create and perpetuate an unjust status quo. For articles, try Google Scholar:

Google Scholar search for bibliography on critical approaches to agriculture. 

Here are some classic books with critical approaches to agriculture and the environment, though not necessarily focused on the United States:

• Land Degradation and Society
• Political Ecology: A Critical Introduction
• Political Economy of Soil Erosion in Developing Countries