Soil Analysis: Most Wildlife Managers accept the necessity of proper fertilization for optimal forage growth of supplemental wildlife plantings, but often overlook liming or soil pH. The two components, fertilization and pH, work together. Proper complete uptake of fertilizer is diminished if soil pH is low. For example, if soil pH is around 4.5, close to 80% of the money you spent on fertilizer is wasted. In addition, important soil nutrients such as zinc, manganese, selenium, magnesium, boron and iron are either unavailable or toxic to some plants if soil pH is not correct. It cannot be stressed enough the importance of this relationship.
Liming and pH: Soil pH is a measure of the acidity or alkalinity of the soil. This measure ranges from 1 to 14, with 7 considered neutral. Any value less than 7 is categorized as acidic, while values greater than 7 are alkaline. Normally, soils will not be more acidic than 3.5 or more basic than 10. Most soils in Michigan, which have not been previously limed, will be moderately acidic (usually around 4.0 – 5.0) due to humid conditions and the decomposition of leaves, twigs, and other plant materials. The goal of the wildlife manager should be to achieve a soil pH of 7.0. A value of 6.7 – 7.0 will net maximum productivity, especially on legumes and, to a lesser extent, on cereal grains such as wheat and oats. Proper inoculation of legumes is even more critical on acidic soils because the bacteria which aid legumes in fixing nitrogen are more limited on acidic soils.
Your soil analysis will be returned with site-specific recommendations on lime application rates. Don’t be surprised if you receive a recommendation of 3 tons of lime per acre on some of your sites which have never been limed. (In the absence of soil testing, a rule of thumb for lime application is to add 2 tons per acre every third year.) You may also learn that some types of soils require more lime than others to achieve the same result. Clay soils will typically receive higher recommended lime application rates than some of the more sandy soils.
