Manage Nutrients AND High Fertilizer Prices
Data Drives Fertilizer Efficiency
Things were already looking up when Dr. Karl Wyant, Nutrien’s Director of Agronomy, spoke to the audience at Commodity Classic this spring. Many growers are seeing the light at the end of the three-year drought tunnel. Fertilizer prices and supply logistics seem to be improving. And there are strong market signals for corn, soybeans and wheat, and early indications that seeded acres of these crops are on the rise.
However, there are still some issues that growers should be aware of. “We continue to demand more of our soil, and the NPK there, year over year,” said Dr. Wyant. “There is no substitute for NPK at the core of the crop’s basic biology and growth requirements. As such, yield is strongly influenced by proper nutrient management.”
Critical Values
The increased pressure on the soil is partly due to ever-increasing yield demands of hybrid varieties. Nitrogen is prone to gassing-off, leaching or run-off depending on soil and weather conditions while Potassium and Phosphorus have a little more “wiggle room”. There are ways to manage the nutrient levels to provide optimal yields and efficiency.
Soil tests provide data about where farmers’ fields are in relation to the critical level and help growers manage soil health and financial investment. The Critical Value is the point as shown on a soil test, above which there is limited fertilizer response. Applying fertilizers on fields that test over the Critical Value might not make financial sense. Conversely, when soil test values are below the Critical Value, fertilizer response tends to increase and provides a financial benefit. It lies between too much and too little P or K in the field. Growers are often juggling between building up levels that are too low or drawing down nutrients where the levels are higher than needed. Knowing where these levels are in the field prevents over-spending or under-performing.
“This is a key metric to build into your observation and data metrics that will help drive nutrient decisions,” said Dr. Wyant. He also offered a rule of thumb to help when trying to bring P and K levels up or down. Depending on soil conditions:
- For every 20 pounds/acre of P205 above crop removal, the soil test level will increase by 1ppm.
- For every six pounds/acre of K20 above crop removal, the soil test level will increase by 1ppm.
These relationships work in the opposite direction in a drawdown scenario. “By knowing how the added nutrients will impact critical soil values, growers can manage the investment with more precision.”
Rotate your way into nutrient management
And the 4Rs are another critical piece when managing nutrient use and investment. “You will get more out of your nutrient investment, get more into the crops, and lose less to the environment or other inefficiencies if you apply the 4Rs. Adding new fertilizer or formulation technologies to your existing program can also help you improve uptake efficiencies.”
Dr. Wyant shared his words of wisdom around the application of the 4Rs.
Source
“Soil test. Knowing what is there now and what the crop will need means you don’t spend money unless you have to. Formulation technology also drives efficiency.”
Rate
“Soil test. Feed yield goals. Not all fields are the same so avoid under- or over-application.”
Time
“Apply when the crop needs it. Formulation technology will reduce inefficiency or losses.”
Place
“There are so many options today. Broadband vs broadcast. Two-by-two or in furrow. Foliar or liquid. It isn’t one size fits all.”
A key nutrient management tool that ties into the 4Rs is understanding removal rates. “Depending on what fertilizer price is bugging you, you can actually rotate your way into adding crops with higher or lower fertilizer requirements and get through these high fertilizer prices with just rotation decisions,” said Dr. Wyant.
“A fifth R, crop rotation, can be useful for saving on fertilizers as different crops have different nutrient requirements. Take the rotation switch from corn to soybeans for example. Soybeans can make their own nitrogen and therefore use considerably less nitrogen fertilizer relative to corn. This also extends to phosphate and potassium as well. The graphic below shows the different phosphate and potassium requirements and how they differ between supporting optimal yields of both crops. Corn requires more phosphate than soybeans and, on the flipside, soybeans require more potassium.”
At the end of the day, having as much information as possible drives better decision making. “Use your data to drive your fertilizer efficiency so that you can get as much out of your fertilizer dollars as possible.” Understanding critical value and removal rates, using the 4R Basics, and having a strong agronomy partner to share their knowledge and ideas, are all essential tools in nutrient stewardship.
To hear more from Dr. Wyant, watch this video of his presentation.
