Dr. Alan Blaylock brings extensive North American and international experience in nutrient management to the agronomy team. University studies and service as a university extension soils specialist prepared him for a long career in the fertilizer industry. Having managed both domestic and global research and education programs, Dr. Blaylock has a wealth of experience in applying science-based nutrient management principles and products to solving practical questions. Dr. Blaylock earned Bachelor of Science and Master of Science degrees in agronomy and horticulture from Brigham Young University and a Ph.D. in soil science from Iowa State University. He has been in agriculture his entire life — from his childhood on an irrigated farm in eastern Oregon to teaching soil science at Iowa State University to his current role as an agronomist at Nutrien. These diverse experiences helped Dr. Blaylock develop the skills to excel in translating complex scientific principles into practical solutions. Although early in his university studies he explored computer science as a profession, deep family roots in agriculture brought him back to the people and values of his heritage. His career satisfaction comes from helping others improve the performance of nutrients and cropping systems. Dr. Alan Blaylock is a recipient of the 2022 Great Plains Soil Fertility Conference Leadership Award. The Fluid Fertilizer Foundation also recognized Dr. Alan Blaylock with the Werner Nelson Award for his outstanding contributions in the development of soil fertility practices and plant nutrition management to increase crop yields for the benefit of North American farmers and consumers
Farming is never straightforward, and when it comes to crops, potatoes come with a unique set of challenges. Managing nitrogen in potatoes is complex but understanding what sets them apart from other crops empowers growers to alleviate the risks they face.
Risks in potatoes
Applied nitrogen faces two risks that differ based on the form applied and the nitrogen transformations that occur after application. Volatilization can occur when urea is left on the soil surface. This typically occurs in the first week to 10 days, as the urea is converted to ammonium. During this conversion, some ammonia can volatilize into the surrounding air. In typical potato growing conditions, where there is frequent rainfall or irrigation, sandy soils, and early incorporation of applied urea into the soils, this risk is fairly minimal.
The second risk is associated with nitrate in the soil. Nitrate can be lost via leaching, common in well-drained soils in wet or irrigated regions or lost via denitrification in oxygen-deficient soils by bacteria in the soil. These are longer-term risks, as they can occur at any time throughout the growing season. And because potatoes are often grown under irrigation in sandy soils, the leaching risks can be greater than those of other crops. Potatoes need nitrate during their rapid growth phase, meaning untimely losses can negatively impact crop yield and quality.
Challenges
Potatoes face challenges beyond just the types of soil they’re grown into. They are shallow rooted, meaning their root zones are small, increasing their susceptibility to leaching. Also, as mentioned above, they need nitrate at the right time to maximize their rapid growth phase. Potatoes generally require a high nitrogen rate as well, meaning there is a high potential for nitrogen leaching. Any applied nitrogen that is lost is a large investment down the drain. Overall, potatoes are a high-value crop that must be intensively managed to realize the best returns.
The importance of nitrogen management
To get the most from applied nitrogen, growers can manage the source, timing, rate and placement. These are all part of the 4R Nutrient Stewardship principles. For example, potato growers frequently apply nitrogen in multiple applications to supply nitrogen closer to time of crop need. Another option is to choose a fertilizer that manages both the nitrogen form and timing, like using a controlled release nitrogen to deliver nitrogen as needed or using a nitrification inhibitor to slow conversion to nitrate.
What are enhanced efficiency nitrogen fertilizers?
Enhanced efficiency fertilizers are an option for managing nitrogen in potatoes and growers should know about the different types and how they’ll perform. An enhanced efficiency fertilizer is a fertilizer that is modified in some way to provide increased nutrient availability and reduced potential nutrient loss to the environment when compared to an appropriate reference product.
Under the banner of enhanced efficiency fertilizers, there are slow-release fertilizers as well as stabilized fertilizers. Slow-release fertilizers release plant-available nutrients at a slower rate than an appropriate reference product. Included in this category are controlled-release fertilizers, which are products engineered to provide nutrients over time at a predictable rate under specified conditions.
Stabilized fertilizers are fertilizer products that have been amended with an additive that reduces the rate of transformation of a fertilizer compound, extending the time of nutrient availability to crops compared to an unamended form. These include urease inhibitors and nitrification inhibitors.
What are the benefits of nitrogen enhanced efficiency fertilizers in potatoes?
Reduced nitrogen loss to the environment
Improved nitrogen use efficiency
Regulate the amount and form of nitrogen supplied
Simplify nitrogen management for growers
Increase productivity and profitability in potatoes when used properly
Which enhanced efficiency fertilizer performs best in potatoes?
Enhanced efficiency fertilizer type
Urease inhibitors
Nitrification inhibitors
Controlled-release fertilizers
Benefits:
Controls volatilization
Reduces leaching and denitrification potential
Controls volatilization, leaching and denitrification
Regulates timing of nitrogen supply
Improving nitrogen management in potatoes with enhanced efficiency fertilizers
Stabilized fertilizers that use urease inhibitors control volatilization, but little else. Because potatoes are so often grown in sandy soils in regions with high rainfall or irrigation, they are not overly useful for potato growers.
Those that use nitrification inhibitors can help control leaching and denitrification, but they do not regulate nitrogen supply to crops.
This is where controlled-release fertilizer products truly shine for potatoes. They reduce all loss mechanisms in any soil type while regulating nitrogen supply to potato crops, providing the best overall benefits. Increased nitrogen efficiency results in greater yields and profits, reduced environmental impacts, and because the release is controlled, fewer applications are required to meet the demands of potato crops, meaning reduced field passes.
