Excessive amounts or the wrong type of fertilizer will not provide an effective treatment for your lawn and may increase the risk of groundwater contamination. The following are some management practices that should be used to assure a healthy lawn and reduce the infiltration of lawn chemicals into the water supply. Soil Testing - Soil testing can be helpful if your lawn is not performing as it should.
Soil testing is costly for a home owner since home test kits are of little value for Arizona soil.
To obtain an accurate soil test a soil sample must be sent to a certified soils laboratory. County Extension offices have a list of labs for your use. In general, soils in Arizona will be lacking in nitrogen and phosphate. Regular applications of these two elements should prevent the majority of problems due to nutrient deficiencies. To avoid over application of nitrogen it is best to apply small amounts of more frequently.