Which new deal reforms most directly targeted the basic problem of the victims of the dust bowl?

Several New Deal programs were targeted at the soil erosion problems that led to the Dust Bowl:

Civilian Conservation Corps Act (1933)
Soil  Conservation Act (1935)
Works Progress Administration (established in 1935)

As an example, the Works Progress Administration (WPA) and Civilian Conservation Corps (CCC) worked in conjunction with the US Forestry Service to plant millions of trees to serve as windbreaks for thousands of farm properties.

Other New Deal programs targeted the poverty of the victims of the Dust Bowl, such as:

The Agricultural Adjustment Act (1933), which offered subsidies to farmers to limit production of certain crops to improve crop prices;
The Resettlement Administration (1935), which worked to relocate struggling families;
The Farm Security Administration (1937), which took over where the Resettlement Administration left off and expanded efforts to improve the lives of poor farmers and sharecroppers.