Before we get your question assigned to a rangeland or soils specialist, they will need to know where is your "area?" Your county would provide enough information to give you a better answer.
Thank you for your question. It may take a few more questions to give you a good answer because typically native grasses survive with limited fertilizer input.
1. Do you have access to supplemental water via irrigation or sprinkler?
2. Do you happen to know some of the grasses?
3. What do you intend to do with the grass (graze?)?
The best solution would be to complete a soil test to find which nutrients are lacking. Usually nitrogen is limited but if the soil pH is high (above 8), other nutrients may be unavailable to plants.