"Starved by lack of plant food. Nourished on phosphate and lime." This image would be useful to a student writing a research paper about what New Deal agency?

The image would be useful to a student writing a research paper about the Civilian Conservation Corps (CCC). The CCC was a New Deal agency established during the Great Depression to provide employment for young men in conservation projects, including reforestation and soil erosion control. The image of a plant being starved by lack of plant food and nourished on phosphate and lime likely relates to the work of the CCC in restoring soil fertility and promoting plant growth through the use of fertilizers.