To grow the healthiest flowers, fruits and vegetables, test your soil's pH levels. Home testing kits are available at garden supply centers and in mail-order seed catalogs. Another option is to have your soil tested by the office of your Agricultural County Extension Agent. They will send you a report detailing what, if any, amendments are needed to adjust the soil's pH level and fertility. Soils with a pH below 7.0 are considered acid and soils with a pH above 7.0 are considered alkaline.
Measures Soil Fertility
A pH test determines the fertility of the soil. Most soil nutrients are available for plants to use when the soil's pH is between 5.8 and 6.5, according to Clemson University Extension. Higher pH levels cause common nutrients such as phosphorus, iron, manganese and zinc to be less available for plants, making the soil less fertile. At pH levels below the ideal range of 5.8 to 6.5, the level of manganese can be toxic to some sensitive plants, which also makes the soil less fertile.
Determines Necessary Soil Amendments
The pH level of your soil determines how much and what type of soil amendments to add. These amendments will adjust the soil's pH level, bringing it to its optimal level. The test results will determine the amount of agricultural lime needed to reduce the pH level or the amount of agricultural sulfur needed to raise the pH level. This pH range helps plants better utilize the soil nutrients.
Eliminates Over- or Under-fertilizing
A report from your county extension agent detailing the results of the pH test will also include recommendations as to the amounts and types of fertilizer to add. This reduces plant nutrient deficiencies such as slow growth, blossom drop and low crop yields if the soil is under-fertilized. The results of the pH test will also help avoid over-fertilizing garden soil, which can lead to excessive vegetative growth at the expense of flowers or fruit, delayed maturity of crops and salt burn.