It’s natural to look for cost-cutting strategies when commodity prices are on the cusp of breakeven. Yet experts advise producers to be careful about placing inputs at the top of the trim list this spring.
“Provide an estimate of what you expect” for prices, advises Dr. Robert Mullen, resident agronomist at PotashCorp, the world’s largest fertilizer producer. “Then look at input costs and calculators to help gain confidence with the decisions you’re making.”
For example, data gathered over the past couple of years from fields in the Midwest, Mid-Atlantic and Southeast indicate increases in potassium deficiency, Mullen points out. Every field is different, but producers must act when they see trends indicating high-yielding corn hybrids are experiencing stress getting proper nutrition.
“If you have that historical experience of finding that potassium deficiency, you’ve got to do something different,” he says.
In terms of managing other nutrients such as nitrogen (N), producers must also realize the many sources of the nutrient in calculating application needs, adds Dr. Nathan Mueller, cropping systems and agricultural technologies educator, Nebraska Extension. Manure, irrigation water, soil organic matter, soil nitrate-nitrogen and previous crops can all provide N credits that can help save farmers money.
“Small amounts of starter phosphorus can pay back big if you know you have low phosphorus testing soils,” Mueller explains. “For example, I have seen 10 lb. of phosphorus per acre applied as starter result in a 6-bushel-per-acre increase in soybeans and 15 bushels per acre in corn when soil test phosphorus were very low. However, we will be falling behind as phosphorus removal is higher than what was applied, so we can’t maintain yields year-in-and-year-out doing this.”
Dig Into Data. Soil tests are an excellent starting point for gauging nutritional needs for crops, Mullen says. These should be conducted in multiple locations, and information should be compared to historical data to identify problematic trends in nutrient availability.
In some places, Mullen adds, economics might allow producers to spread extra phosphorus and potassium for benefits extending into the 2016 planting season. That’s particularly true if a producer anticipates input prices will rise in the next year. Yet for many Midwest producers, annual application is a safer bet because of the higher percentage of rented acres and uncertainty surrounding who will farm which ground year-to-year.
“If you are experiencing those nutritional deficiencies, you’re not in the best position to be successful,” Mullen notes. “We understand you have to stay focused on margins. Invest in nutrients when needed.”
Variable-rate application of inputs can also help farmers maximize their investment, Mueller adds.
“Generally consistent high-yielding areas have lower soil test phosphorus and potassium, while low-yielding areas have higher values,” he points out. “This is where yield maps and running multi-year yield analysis can help you make judgement calls.”
He suggests three approaches to smart input management, depending on your relationship to the farmland:
1.Cash Renting With Uncertain Tenancy: “The nutrient deficiency removal or sufficiency approach really looks at how much fertilizer do I need to remove phosphorus or potassium deficiency and maximize profit in this year’s crop based on my current soil test value,” Mueller explains. “This approach may often apply less phosphorus or potassium than what is removed at grain harvest causing soil-test phosphorus or potassium to decline over time, making applications higher in coming years.”
2.Owned Ground Or Long-Term Tenancy: “The build and maintenance approach looks at a target soil-test phosphorus or potassium,” Mueller says. “You can build your soil-test phosphorus or potassium up to the target value over a number of years, or you can draw down your soil test values if they are high by not applying any fertilizer. Your goal is to keep the soil-test level at or above where the crop is not responsive to additional fertilizer. When you own the farm or are confident in long-term tenancy (share crop or cash rent), you do have the option to apply extra phosphorus or potassium when fertilizer prices are low or in profitable years. I looked at soil sample results with a farmer who had been on a fairly aggressive fertilizer program for the past five years. Soil-test phosphorus and potassium were all high, and the farm can use the drawdown phase in the build and maintenance approach for the next two years.”
3.New Ground; Fields With Stable Yields And Soil Tests Conducted In The Past Five Years: “The crop removal approach is where you apply what you removed with the grain last year or you think you will this coming year,” Mueller notes. “Here, most people use reference values from a table on the average phosphorus and potassium per bushel of the crop removed. However, these are average values and might not represent what concentration was in your grain. Grain samples could be taken to verify concentrations.”
For more information on managing nutrients and their financial returns, visit the PotashCorp Nutrient ROI Calculator. You can also view PotashCorp videos about the value of spring nitrogen application and potassium.
For nitrogen evaluation, Mueller recommends the University of Nebraska’s Corn Nitrogen Recommendation Calculator. You can also explore micronutrient fertilizer application research at the university by visiting the Nebraska On-Farm Research Network. Mueller says micronutrients often don’t pencil out broadly; instead, some work in specific geographies, such as those for manganese-deficient soybeans in the Great Lakes and Atlantic Coastal Plain. Finally, you can read more at Mueller’s Crop Tech Cafe blog.