What organic materials provide phosphorus naturally?
Written by
Nguyen Minh
Reviewed by
Prof. Charles Hartman, Ph.D.Organic phosphorus materials provide nutrients to plant life slowly, thereby improving the soil's structure. Natural phosphorus options, such as bone meal and rock phosphate, nourish plants without synthetically derived phosphorus. Phosphorus is released through microbial decomposition over several months. This gradual, stepwise process fosters sustainable fertility in your garden or farm.
Animal-Based
- Bone meal: 15-27% P₂O₅ content, releases over 3-6 months
- Fish bone meal: Faster decomposition than regular bone meal
- Composted poultry manure: High phosphorus with nitrogen balance
- Blood meal: Secondary phosphorus source with high nitrogen
Mineral-Based
- Rock phosphate: 30% P₂O₅ but requires pH below 6.5
- Soft rock phosphate: More soluble than hard rock varieties
- Colloidal phosphate: Finely ground for better availability
- Guano: Seabird/bat deposits with concentrated phosphorus
Plant-Based
- Composted cottonseed meal: Balanced NPK with slow release
- Kelp meal: Trace minerals plus moderate phosphorus
- Alfalfa meal: Stimulates microbial activity for mineralization
- Green manures: Buckwheat and mustard accumulate phosphorus
Microorganisms, including bacteria and fungi, facilitate the mineralization of phosphorus from organic materials. They degrade amendments like bone meal for phosphorus. Soil temperature and pH level are crucial factors for the release of this nutrient. Soil temperatures should ideally be kept between 55-75°F (13-24°C) for good microbial activity. It is also important not to use chemical fungicides that may harm beneficial species.
For optimal utilization of organic phosphorus, it is essential to employ suitable application methods. To incorporate bone meal (phosphorus), mix it into the soil before planting, at 10-20 lbs/100 sq ft. Rock phosphate should only be used if the soil pH is below 6.5; in other cases, use bone meal. After composting poultry manure, let it sit until it decomposes to prevent nitrogen burn to young plants.
Utilize organic sources in integration with mycorrhizal fungi, if beneficial nutrient uptake is desired. These fungi, in cooperation with plant root systems, increase phosphorus uptake 30-50%. If transplanting, easily obtain a reliable source of mycorrhizal fungi and incorporate it into the planting holes. Avoid synthetic fertilizers that are high in phosphorus, which may unknowingly suppress the growth of mycorrhizal fungi.
Organic phosphorus provides soil benefits that go beyond supplying nutrients. For example, organic phosphorus enhances water-holding capacity in sandy soils. Organic phosphorus improves structure in clay soils. Organic matter serves as food for earthworms and beneficial microbes. These benefits create resilient growing conditions time after time.
Read the full article: Phosphorus Deficiency Plants: Signs and Solutions
