The clock is ticking. Finalizing your planting plan for the 2025 season is a must, and one strategy that should not be overlooked is soil fertility. If you did not have time to test your soils in the fall, you can still prioritize soil sampling in early spring to determine what you need to feed the crop.
“There’s still time to make nutrient amendments to your soil before you hit the field. Fertilizers can be applied in the spring either pre-plant or pre-emerge if you were unable to make a fall pass.”
Tom Larson, Stine® Seed Company’s director of agronomy
The big four
There are four nutrients that are the core drivers for healthy plants: nitrogen, potassium, phosphorus and sulfur. Each serves a critical role in the early vitality and season-long success of the crop.
Nitrogen
Often considered the most important nutrient in crop production, nitrogen is essential for the photosynthesis process as it’s a nexus for chlorophyll production. Nitrogen can be applied in the spring either pre-plant or pre-emerge or in-season as a sidedress. Our experts recommend applying nitrogen with sulfur.
Sulfur
When it comes to sulfur — a critical component to the photosynthesis process — spring is often an ideal time to apply the nutrient as it can be prone to leaching if applied in the fall without a stabilizer, leading to less availability for the crop come spring.
“Sulfur works in tandem with nitrogen as it helps metabolize nitrogen and supports the uptake of the nutrient into the plant,” says Larson. “For spring applications, we typically recommend using ammonium sulfate or ammonium thiosulfate at 1 pound for every 5 to 10 pounds of nitrogen. It needs to be plant available as soon as the crop needs it, so the earlier you can get it on, the better.”
Potassium
According to experts from the University of Minnesota Extension, potassium supports the mobility of nutrients in the plant tissue, as well as water and carbohydrates, among other important functions. It’s primarily recommended to apply potassium pre-plant as a broadcast application as close as you can to planting, especially in sandy soils as the nutrient has some mobility.
Phosphorus
Like potassium, phosphorus should be applied as close to your planting window as possible. Potassium is the least mobile of the big four nutrients, so it tends to stay put. Phosphorus has an important role in the photosynthesis process, as it converts sunlight into plant growth. Phosphorus and potassium can be and often are applied at the same time.
Planning fertility in a tough economic climate
While commodity prices remain volatile, there’s no question that it’s still a tough economic year. The costs of inputs will be weighing on growers’ minds this planting and growing season. Our experts note that optimal fertilizers are more of a concern in corn production than in soybeans, so prioritizing which fertilizers make sense, and which crops you need to apply them to will be important. Here are some questions we recommend asking before determining your fertilizer options.
What do your recent soil testing results relay?
Our experts agree that a sound fertility plan should always start with soil testing to determine your baseline for fertilizers. It should help you decipher what is necessary to replace this year and what could maybe wait until later in the season or next year.
What’s your previous crop history?
Did your crops struggle late in the season because of nutrient deficiency? If so, if it was a problem for you last year, it’s likely going to be a problem this year if you didn’t adjust fertility after harvest.
What’s your budget, even if it’s your break-even budget?
Look at your budget and determine which inputs are cost-effective for you this year. At the end of the day, many of these inputs will contribute to greater yield, which means more money back in the long run. You can also look at different, more cost-efficient, strategies for applications, such as looking for different sources of nitrogen, splitting nitrogen applications or reducing the amount of phosphorus and potassium if they are within or close enough to your baseline yield goals
No matter your situation, Stine agronomists are available to provide year-round support to help you make these tough agronomic decisions. Contact your local Stine sales representative who can connect you directly with a Stine agronomist in your area.