Maximize Nitrogen Fertilization Practices
CropLife Media Group webinar presents best management practices for optimizing N application.
April 6, 2011
Ensuring nutrients are available to the crop during the growing season starts with making the right agronomic and economic decisions. And dealers and growers who implement best management practices when it comes to nitrogen fertilization can boost yields and improve their bottom line.
This was the subject of CropLife Media Group's webinar, "Maximize Nitrogen Fertilization Practices," presented by Dr. Ron Heiniger, professor of crop science at North Carolina State University, and Jake Sanders, vice president of market development at Specialty Fertilizer Products (SFP). The two experts offered insight into managing nitrogen application to maximize yield and presented solutions for protecting that nitrogen from volatization and leaching. (View Webinar on-demand)
A Stepwise Approach
How much nitrogen should I apply? Answering this question is a challenge for many growers and dealers, Heiniger said.
"Determining how much fertilizer should be applied to a crop can be broken down into three parts: crop nitrogen requirement, nitrogen available in the soil, and fertilizer use efficiency," he said. "The problem is these components can remain unknown at the time of planting. Plus, there are several factors that impact this process, like weather, genetics, pest damage and soil water-holding capacity."
Successful nitrogen management in corn production requires a well, thought-out plan, Heiniger said.
"We can improve our efficiency by taking a stepwise approach, which takes into account as much information available along the steps of the process," he said. "It uses this information to tell us how much nitrogen is coming from the soil and how much we need to add to the crop."
Heiniger said there are four key stages when growers and dealers should address a crop's nitrogen needs:
1. Planting. The first step of any nitrogen application system occurs at planting time, Heiniger said. "Fifty to 100 pounds of nitrogen at planting improves nutrient use efficiency and leads to higher yields," he said. "Ensuring adequate nitrogen fertilizer influences ear size and root growth. This in turn improves the plants' ability to uptake soil nitrogen."
2. Layby. The layby period is an ideal time to analyze a corn crop's nitrogen use, Heiniger said. "Let the plant give us an indicator at layby what the soil nitrogen is," he said. "We can use the information from tissue tests and sensors to help assess what the plant's nitrogen requirements are at this stage."
3. Measured release. One of the key components of the stepwise approach is to ensure nitrogen is available throughout the season, Heiniger said. "Often times it can be difficult to apply nitrogen later in the season to take up the slack from what the soil can't supply," he said. Controlling the release of nitrogen can be accomplished through nitrogen coatings and additives, such as NutriSphere-N. "NutriSphere-N helps nitrogen to release to the crop when you need it."
4. Assessment. Conducting a stalk nitrate test at the end of the season is an excellent postmortem assessment of nitrogen management, Heiniger said. "We can use that valuable information when planning for the next season," he said.
Protecting Nitrogen Applications
During the webinar, SFP's Sanders addressed a problem that impacts nitrogen's effectiveness: Poor efficiency.
"We know that up to 50% of your nitrogen can be lost, possibly even more under extreme conditions," he said. "This occurs through volatilization, nitrate leaching and de-nitrification. NutriSphere-N is designed to overcome these mechanisms of nitrogen loss. We want to keep that nitrogen exactly where we put it, which is available to that crop."
NutriSphere-N starts with a water-soluble polymer that contains an enormous negative charge. "NutriSphere-N is going to sweep those positive charges out of that urea, and deactivate that enzyme to allow that urease to stay where we put it," Sanders explained.
In addition, NutriSphere-N provides protection for nitrogen regardless of the timing of application.
"It effectively manages nitrogen without killing microorganisms in the soil and without limiting nitrogen availability through a hard shell coating," he said.