It's a combination of factors that will contribute to the loss of top-soil. Below I quoted the main references that briefly touch on soil health.
"More heavy downpours may increase the likelihood of property damage, travel delays, and disruption in services. Sediment runoff and erosion may clog reservoirs and reduce storage capacity."
Erosion is harmful because the top six inches of the soil has the majority of microbial life that contribute to healthy soil. When their ecosystem is disturbed, it takes years for it to come back. No amount of fertilizer or additives will help in it's absense and only worsens the health of the soil.
"Midwestern agricultural lands make up two-thirds of the region's land area and produce 65% of the nation's corn and soybeans."
Corn and soybean production has historically used harmful chemicals and harmful farming practices. These techniques harm the microbial life in the top-soil in addition to other ecosystems.
Industrial farming practices are negatively impacting ecosystems such as insects, birds, and microbial soil life.
"In the long-term, climate impacts are likely to have increasingly detrimental effects that increase variability in crop and agricultural production"
When these crops start to die off, the soil is going to be exposed to severe weather conditions and will only make it worse for the microbial life to live. Healthy soil need's protection from UV, typically that's in the form of a mulch layer (leaves, twigs, bark, wood chips, plants, bushes, trees, etc...)
'Many tree species are expected to gradually shift their ranges northward."
The forest edge is Nature's sign of the best growing conditions. Tree's provide protection, energy, and food for top-soil. Without them, it will require significant energy and expense to simulate what they naturally provide.