If only one or two fertilizer nutrients are needed, you may prefer to purchase fertilizers containing only the needed minerals and apply them separately. Some common fertilizer sources are:
ammonium nitrate 33-0-0-0-0 33 % Nitrogen
ammonium sulfate 21-0-0 21 % Nitrogen
bloodmeal (organic) 16-0-0 16 % Nitrogen
sulfer-coated urea (slow release) 36-0-0 36 % Nitrogen
treble superphosphate 0-45-0 45 % Phosphate
bonemeal (organic) 4-17-0 17 % Phosphate
muriate of potash 0-0-60 60 % Potash
woodashes (organic) 0-0-? 6 % Potash
Soil amendments adjust the pH (soil acidity or alkalinity level) and supply calcium (Ca) and magnesium (Mg) to the soil. Most lawns grow best in moderately acidic soil. Soils with a pH from 5.5-7.0 do not need soil amendments to adjust the pH level. Lime is calcium carbonate. It will raise soil pH (reduce acidity) and supply calcium.
Dolomite lime is calcium-magnesium carbonate. It will supply both calcium and magnesium to the soil and raise soil pH. Sulfur is used to lower soil pH. Apply soil amendments based on the recommendations from a soil test. The recommended quantities of lime or dolomite should supply enough calcium or magnesium to last several years.
Gypsum Seldom Improves Soil Structure
Gypsum (calcium sulfate) has been promoted as a soil amendment to improve soil structure. In the vast majority of cases, it will not work. Gypsum only improves structure when the problem results from excessive sodium in the soil, which is a rare condition.
Apply lime and other soil amendments in the fall. With vegetable gardens and flowerbeds, till the lime into the soil. On lawns and perennial plantings, fall application allows the winter rains to dissolve and carry the amendments into the soil. Do not apply lime and fertilizer at the same time. Lime, if needed, should be applied at least 30 days before any fertilizer application. Next...