Phosphorus: Top 5 Things You Need to Know

Photo courtesy of Alabama Cooperative Extension Services

Phosphorus is an essential nutrient for plants and animals (including humans). Just like the other essential nutrients, phosphorus deficiency can have serious effects on plant growth, maturity and yield. We’re breaking down the top five things you need to know to maintain healthy phosphorus levels in your crops.

1. Most phosphorus is not readily available to plants

While there are large amounts of phosphorus in most soils across the corn belt, it’s not very easy for plants to utilize. Phosphorus is often present in mineral and organic forms, and slowly becomes plant-available over time as minerals weather or through microbial degradation. Supplemental P through fertilizer and manure applications is often necessary to prevent phosphorus deficiency in crops.

2. Phosphorus is heavily absorbed by soil

Compared to the nitrogen cycle, the phosphorus cycle is less complex, and P is less easily lost from soils. While not much plant-available phosphorus is found in soil, P is retained well, so monitor your soil nutrient levels carefully after you start supplementing phosphorus.

If you apply more P than you remove when harvesting crops, you’re spending your dollars on unnecessary inputs (a.k.a. wasting your money). Utilize the Agronomy 365 Dashboard for thorough in-season soil and tissue sampling to help monitor nutrient levels in your soil and your plants.

What if we told you that applying phosphorous may be a thing of the past? With how easily P is tied up into the soil, our team of scientists have set out to discover the best way to unlock phosphorus rather than wasting dollars on applying more. Read more on a 3-year trial that has used no commercial P (flip the page to see the data).

3. Phosphorus is key for photosynthesis

Phosphorus is vital in ATP, which is formed during photosynthesis and produces energy in plants. Crops rely on P to capture and convert energy from the sun into useful plant compounds. All growth and plant activity relies on this energy, making it clear why P is so important in crops. Stimulated root development, strengthened stalks and stems, more uniform and earlier crop maturity, improved nitrogen-fixing capabilities and disease resistance are just some of the growth factors associated with phosphorus.

4. Deficiency is difficult to diagnose

Phosphorus deficiency is harder to identify than nitrogen or potassium deficiencies. The primary visible symptom during early stages of phosphorus deficiency is stunted growth, which is hard to distinguish, especially during a season with poor growing conditions.

Once additional visual cues show up, it may be too late to correct the deficiency. Dark blue discoloration in leaves and purplish discoloration in stems signal a lack of P in crops such as corn. This increased difficulty in diagnosing emphasizes the importance of soil and tissue sampling for accurate nutrient level assessments throughout the growing season.

5. Livestock diets rely on phosphorus

Humans and other animals use phosphorus to make bones, teeth and shells—and it is an important component of cell membranes. P is especially important in building livestock bone strength and muscle production.

A large percentage of phosphorus found in livestock feedstuffs is not available to be absorbed and utilized, much of it is excreted. Just like we add microbes to soil to help with nutrient uptake, adding phytate enzymes to animal feed helps livestock digest P, making it more available to the animal.

When it comes to essential nutrients, phosphorus will always be near the top of the list. This nutrient plays a key role in energy production, which impacts all stages of crop development. Keep a close eye on nutrient levels in your crops and soils to ensure your plants have enough phosphorus to stay healthy.