How to Increase Phosphorus & Potassium in the Soil
- 1). Perform a soil test to determine the balance of nutrients in your soil. An inexpensive test from the hardware store provides the level of both phosphorous and potassium, but one completed by your county extension office provides a more thorough evaluation of your soil.
- 2). Read the soil analysis report from the soil testing service or read the accompanying material with your soil test kit to determine your soil needs.
- 3). Purchase fertilizer with a formula that is high in phosphorus and potassium, but low in nitrogen, if your soil test indicates that the soil lacks both phosphorous and potassium. Otherwise, purchase a formula that matches your soil's needs.
- 4). Spread the fertilizer over the top of the gardening area. Follow the recommended application rate when applying fertilizer, as too much fertilizer can damage plants.
- 5). Work the fertilizer into the top 6 inches of the soil with a garden tiller.
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