Too Much Phosphorus Fertilizer: A 20,000-Ton Problem

Phosphorus is an essential nutrient for plants, but too much of it can be harmful. Excess phosphorus can lead to water pollution, algal blooms, and fish kills. It can also damage crops and make soil less fertile.

In the United States, farmers apply about 20,000 tons of phosphorus fertilizer to their fields each year. This is more than twice the amount that plants need. The excess phosphorus runs off into rivers, lakes, and streams, where it can cause serious problems.

The Dangers of Excess Phosphorus

Phosphorus is a major pollutant of surface water. It can cause algal blooms, which are harmful to fish and other aquatic life. Algal blooms can also make water unsafe for drinking and swimming.

Phosphorus can also damage crops. It can cause stunted growth, reduced yields, and poor quality produce. In some cases, excess phosphorus can even kill crops.

The Problem with Phosphorus Fertilizer

Most phosphorus fertilizer is made from mined rock phosphate. Rock phosphate is a non-renewable resource, which means that it will eventually run out. In addition, mining rock phosphate can damage the environment.

There are other sources of phosphorus, such as manure and compost. However, these sources are not always available in sufficient quantities to meet the needs of farmers.

What Can Be Done?

There are a number of things that can be done to reduce the amount of phosphorus fertilizer that is used. These include:

• Using soil tests to determine the amount of phosphorus that is needed. Soil tests can help farmers determine the amount of phosphorus that their fields need. This can help them avoid applying too much fertilizer.
• Using phosphorus-efficient fertilizers. Phosphorus-efficient fertilizers are designed to release phosphorus slowly over time. This helps to prevent phosphorus from running off into waterways.
• Covering fields with vegetation. Vegetation can help to absorb phosphorus from the soil. This can help to prevent phosphorus from running off into waterways.
• Reducing the amount of animal manure that is applied to fields. Animal manure is a major source of phosphorus. Reducing the amount of manure that is applied to fields can help to reduce the amount of phosphorus that runs off into waterways.

Conclusion

Too much phosphorus fertilizer is a serious problem that can have a number of negative consequences. By taking steps to reduce the amount of phosphorus fertilizer that is used, we can help to protect our water quality, our crops, and our environment.

Tips and Tricks for Reducing Phosphorus Fertilizer Use

• Get a soil test. This is the best way to determine how much phosphorus your soil needs.
• Use phosphorus-efficient fertilizers. These fertilizers are designed to release phosphorus slowly over time, which helps to prevent runoff.
• Cover fields with vegetation. Vegetation can help to absorb phosphorus from the soil.
• Reduce the amount of animal manure that is applied to fields. Animal manure is a major source of phosphorus.
• Use alternative sources of phosphorus. There are a number of alternative sources of phosphorus, such as crop residues and compost.

Common Mistakes to Avoid

• Applying too much phosphorus fertilizer. This can lead to water pollution, algal blooms, and fish kills.
• Using the wrong type of phosphorus fertilizer. Not all phosphorus fertilizers are created equal. Some fertilizers are more likely to run off into waterways than others.
• Applying phosphorus fertilizer at the wrong time of year. Phosphorus fertilizer should be applied in the spring or fall, when plants are actively growing.
• Applying phosphorus fertilizer to fields that do not need it. This can waste money and contribute to water pollution.

Useful Tables

Table 1: Phosphorus Content of Common Fertilizers

Table 2: Phosphorus Requirements of Crops

Table 3: Sources of Phosphorus for Crops

Table 4: Benefits of Using Phosphorus-Efficient Fertilizers