The crop has been grown for many years on these soils on the residual nitrogen present in the soil from the native, leguminous vegetation.
The crop has been grown for many years on these soils on the residual nitrogen present in the soil from the native, leguminous vegetation.
在这种土壤里已经种植多年高粱了，依靠天然和豆科植物残存于土壤中的氮养分。