[header] How to buy organic dry fertilizers [title] Test your soil's ph and nutrient levels. [step] Before selecting an organic dry fertilizer, use a soil testing kit to find out what kinds of amendments your soil needs. Buy a home soil test kit from your local garden center, or send a sample to a soil testing lab near you. 
[substeps] Use a test kit or request a lab test that shows both soil ph and nutrient levels. Many universities offer soil ph and nutrient analysis through their agricultural departments.