Fertilizer question are very common on this forum. Most soils will need initial fertility boosting program for growing main crops until cover crops, legumes and other soil health practices make cropping on low/no inputs possible. Maybe this video from one of the masters will help with your efforts.
Neal Kinsey on Soil Fertility for Corn, Wheat and Soybeans
Neal Kinsey on Soil Fertility for Corn, Wheat and Soybeans
