Sweet potatoes, soybeans, and wheat are very much the purview of traditional big ag. They're highly commoditized, which actually makes them not very valuable. Compare a pound of flour (not even wheat crop itself @ $0.50 retail) to a pound of salad greens ($10-15 retail) or a pound of basil ($15-45). The reason the latter products are so expensive is because they're delicate. They don't travel well, have high shrink rates, and can be premiumized due to freshness. On a unit basis, fresh and highly perishable foods are the high value food. They're also the most nutritious.