Maintaining Phosphorus Levels

Overall, the basics of phosphorus management haven’t changed. Soil naturally has very small amounts of phosphorus in a plant-available form. But phosphorus is usually in  mineral and organic forms that must go through a long process of weathering and microbial degradation before they become plant-available. Thus, phosphorus applications are often necessary to maintain adequate phosphorus levels.

Speaking of adequate levels, as new technologies emerge and advanced hybrids are developed, new phosphorus recommendations are coming into play. In 2023, Iowa State University updated their nutrient recommendations to meet the demands of production. See how your soil compares to these new standards here. 

Once phosphorus is applied, the soil does a great job of retaining it. When growers apply phosphorus in a liquid form, it is more readily available to the plant and isn’t bound up by other nutrients, like calcium, iron and aluminum. Liqui-Grow’s extensive testing and research has shown that using a balanced fertilizer approach and applying phosphorus at the same time as potassium and other micronutrients provides the best results for your crop’s performance. Using a phosphorus stabilizing product like Avail T5 further protects your nutrients and helps your fertilizer investment pay off even faster. 

To learn more about the technology available for phosphorus applications, watch this Liqui Grow Loop video and contact your local Liqui-Grow sales rep to create a customized nutrient management plan for your operation. Text us at 564-220-2508 or email questions@liqui-grow.com today.  

Managing Nitrogen Levels

To grow yields, a plant has to convert sugars into energy, and nitrogen plays a big role in this conversion. It is a key component of chlorophyll, the process by which a plant harvests sunlight and converts it to sugars used for vegetative and reproductive growth. That’s a long way of saying that you need nitrogen to make grain. In fact, it takes approximately .8 - 1.2 pounds of nitrogen to grow 1 bushel of corn. 

There are several forms and sources of nitrogen, but the most common for field application is ammonium nitrogen (NH4), as it is not easily lost from the soil. Once ammonium nitrogen enters the soil, it is converted into Nitrate (NO3) by microorganisms and used by crops for growth and development. Since nitrate is a water soluble form, it’s more easily lost in groundwater.  

Nitrogen is naturally found in soils, and as the weather warms, mineralization of that nitrogen occurs to convert it into a plant available form. However, the majority of nitrogen in the soil currently is not plant available. And we can’t predict temperatures or rainfall far enough in advance to rely upon mineralization as a sole source of plant available nutrients.

Thus, to manage your nitrogen levels effectively, it’s important to understand your field’s soil type and texture. Loam type soils will retain nitrogen easier than others. Thus, if you have varied soil types throughout your fields, it’s not uncommon to see different nitrogen deficiencies in different fields at different times of the growing season. Fortunately, a crop’s high demand for nitrogen throughout the entire plant makes it easy to spot deficiencies.  

Here are some signs of low nitrogen levels in your soil: (https://www.powerag.com/wp-content/uploads/2018/08/corn-def-nitrogen-2.png)

• Orange & red tint in the midrib of the leaf
• Pale, yellow-ish green plant color (from decreased photosynthesis)
• Poor plant structure, such as stunted plants and withering leaves
• Leaves changing color from yellow-ish green to brown

Of course, the best way to prevent deficiencies is through proper nutrient management. At Liqui-Grow, we recommend applying 32% Liquid Nitrogen to keep your soil healthy and equipped for productive performance each year. It has a balance of 50% urea, 25% ammonium nitrogen (NO4+) and 25% nitrate (NO3-), providing three of the four main sources of commercial nitrogen.

This blend keeps crops fed throughout the season as the nitrate is immediately available and mobile in the soil, while the ammonium is not as easily lost and readily available to plants. The urea in this blend must be converted into ammonium nitrogen to be available to plants, which can occur in warm spring soils in less than a week. 

However, application alone doesn’t guarantee the nutrient will be available to your crop. 

There are four main ways that nitrogen is lost in the soil:

— Photo credit to University of Illinois – 

1. Ammonia Volatilization — When nitrogen is laid on the ground, pH levels change and nitrogen can be lost into the air as gas. Most commonly this happens with urea and can result in up to 30% loss. The best way to naturally prevent ammonia volatilization is with tillage, rainfall or irrigation to push the nitrogen into the soil. However, a surface banding application can mitigate losses to a maximum of about 10%.
2. Nitrogen Leaching — Once nitrogen enters the soil, the nitrate form can be lost when heavy rainfall carries it down into the soil. If leaching occurs more than 6’ below the soil, plants will likely not absorb the nutrient. 
3. Immobilization — When nitrogen is immobilized, it does not flow freely through the soil, making it unavailable to plants. While not a permanent issue, nitrogen accessibility during key periods of plant need could be affected by immobilization.
4. Denitrification – If soils are saturated and void of oxygen, nitrogen gas and nitric oxide can leave the soil in a gaseous form. 

This volatility means timing and method of nitrogen application is key to reducing nutrient loss. Under normal field conditions, it takes urea 3-5 days to convert into ammonium. Using a nitrogen stabilizer, such as ATS or Instinct®, helps slow the conversion from ammonium to nitrate, protecting the nitrogen from volatilization and leaching. 

Additionally, measuring your carbon to nitrogen ratio with a soil test will help keep nitrogen available to plants. A 12:1 carbon-to-nitrogen ratio is ideal for plant performance. Lower ratios will limit microbial activity, while a higher ratio will restrict the soil from releasing nitrogen. To learn the best strategies for managing this ratio, visit with your local agronomist. 

Utilizing the correct nitrogen source and applying the right rate at the right time will keep your crop, your wallet and your environment healthy and strong. To learn more about managing nitrogen in your field, ask a Liqui-Grow Sales Applicator or text us at 564-220-2508.