How to Amend Clay Soil With Super Phosphates
- 1). Familiarize yourself with the super phosphates. Super phosphates are the primary material supplying phosphoric acid in commercial fertilizers. They are the basis of the modern fertilizer industry. Super phosphate is manufactured by mixing equal weights of sulfuric acid and finely ground phosphate rock.
- 2). Amend the soil prior to planting. According to the Cooperative Extension office at Colorado State University, "It is essential to make sure that you amend planting sites with organic material such as compost. A good ratio to use is 1 part compost to 2 parts original soil. When planting, you should also keep in mind that encouraging the root system is the most important thing you can do. Mixing bone meal or super phosphate into the soil as you cultivate is a good idea, but you can also add it into each hole at the time of planting. Phosphate needs to be placed in the soil directly in the root zone."
- 3). Add a thick layer, 8 to 10 inches, of organic compost to the planting area. Aged manure from herbivores (cows, sheep, horses, mules, lamas or goats), grass clippings, leaves, aged, non-treated sawdust, shredded newspapers, straw and kitchen waste can be used. Apply rock phosphates over the compost layer, following the package label instructions for application.
- 4). Cultivate the compost and phosphates into the soil. Use a garden tiller or tractor to repeatedly till the soil as deep as possible. Cultivate in several directions, until the compost and phosphate is thoroughly worked into the soil.
- 5). Apply super phosphate around flowering trees, shrubs and plants in late spring or early summer. Sprinkle it lightly around the base of the plant once per year. Use sparingly; too much can prevent uptake of other vital nutrients.
Source...