Adding phosphorus to your garden soil will improve the quality of your plants’ growth, but a lot of this mineral can be problematic, as it can prevent plants from absorbing other essential nutrients. For example, too much phosphorus in the soil can prevent them from absorbing zinc, iron, or calcium. For this reason, it is better to keep phosphorus levels under control. To do this, you can either use organic fertilizers or purchase a commercial product.
Plants always search for phosphorus
Adding phosphorus to soils is essential to maintain the balance between microbial and plant productivity. P limits the primary productivity of an ecosystem by restricting the amount of nitrogen available. Plants and microbial phototrophs are all P-limited in early successional ecosystems. The addition of phosphorus greatly accelerates the rate of succession for both plants and microbial phototrophs.

Using organic compost to amend your soil is a natural way to balance phosphorus levels. Compost, especially that made from manure, can improve soil condition, neutralize pH levels, and increase P availability. Bone meal releases P quickly and can be applied directly to the soil, and fish meal contains a significant amount of both phosphorus and nitrogen. When added to soil, these fertilizers may be effective for boosting phosphorus levels in your soil.
Soil phosphorus is found in two main pools: the primary and secondary P minerals. Primary phosphorus minerals include apatite, strengite, variscite, and calcite, while secondary phosphorus can be derived from calcium phosphate, iron phosphate, and aluminum phosphate. As plants use phosphorus, they find it easier to absorb it.
Adding phosphorus to soil can increase phosphorus content
Adding phosphorus to soil improves the quality of grain crops and vegetables, accelerates the development of ground cover, and promotes healthy root growth. Phosphorus also helps seeds germinate and develop. Aside from human urine, phosphorus can be found in many organic fertilizers, such as blood meal, burnt cucumber skins, bone meal, and bat guo.
The Potash & Phosphate Institute (PPI) publishes Agri-Briefs that provide information about soil phosphorus levels and nutrient use. Phosphorus levels are measured using five soil tests: Bray P1 and Bicarb. P levels above 20 ppm are best for most plants, while readings below 35 ppm are not a problem. The institute also provides a chart showing the amount of soil nutrients that are being removed by crops from the soil.
The concentration of P in a given soil can vary, but it is usually between 0.001 mg per liter. Soil phosphorus is most available to plants in a zone between six and nine mg per liter of soil. Therefore, adding lime to soil to lower its acidity helps to unlock unusable phosphorus. Phosphorus is also a non-soluble nutrient, and it can easily move around in runoff water. This can result in algal blooms, which are harmful to both the plants and the environment.
Adding phosphorus to soil can lead to phosphorus runoff
When added to soil, P compounds can be soluble in water and easily transfer to aquatic organisms. These animals, called detritivores, can then ingest the P. In addition to detritivores, P can be carried in surface runoff to waterways, where it is absorbed by aquatic organisms and released into waterways. Adding P to soil can cause phosphorus runoff, and if not removed, can lead to a toxic problem for the environment.
The long-term goal of managing P in agriculture is to balance the input and the output. Increasing use-efficiency of P in agricultural systems may be achieved by employing both source and transport control strategies. Agricultural landowners already possess the knowledge and tools to reduce P transport from soils, but a lesser amount of attention has been paid to this issue. Using these techniques can help reduce phosphorus runoff in agricultural systems and preserve soil’s quality.
Moreover, adding P to soil can lead to phosphate runoff, which is one of the most damaging effects to ecosystems. While phosphorus can be recovered from agricultural soils, it is lost as a nutrient. Even if the soil is not affected by runoff, the effect on biodiversity can be disastrous. This problem has been recognized as a global concern for many years, and is only now becoming a focus of attention.