An extremely high percentage of Wisconsin soils are testing below the critical for both potassium and phosphorus. With the potassium balance trend not improving and the phosphorus balance trend actually declining, it’s more important than ever to test your soils to ensure you’re above the critical.
The eKonomics nutrient balance analysis is the industry’s first to annually assess state-by-state nutrient removal records, fertilizer consumption information, and manure data. Findings reveal that a large percentage of soils are becoming depleted of nutrients at an alarming rate, causing many areas to fall below the critical level for potassium and phosphorus. Is your farm among them?
The majority of Wisconsin farm fields are critically deficient in two key soil nutrients, which is decreasing both crop yields and farmer income throughout the state.
These are the findings of the International Plant Nutrition Institute (IPNI), which recently collected more than four million soil samples from farms across North America – including 141,450 in Wisconsin – and had them analyzed by both public and private laboratories.
“This landmark study shows that 65 percent of Wisconsin farms are critically deficient in potassium, while 48 percent are critically deficient in phosphorus,” said Dr. Robert Mullen, Director of Agronomy at Nutrien.
Nutrient Balance Data
|Balance||-7 lb/acre to -6.7 lb/acre|
|Balance||9.6 lb/acre to -19.8 lb/acre|
While the “critically below” figure has improved in the last five years for potassium and phosphorus, historically, potassium nutrient balances in the state are down 125 percent and phosphate nutrient balances are down 268 percent since 1975.
Farmers are leaving thousands of dollars in the field
Given the importance of potassium and phosphorus to crop health and yields, these figures should paint a sobering picture for Wisconsin farmers.
“Under current conditions, 65 percent of Wisconsin farmers are losing money because they are potassium deficient and nearly half are losing out by shorting the soil of phosphorus,” Mullen said. “When times get tough and crop prices are down, the natural tendency is to pull back on your phosphorus and potassium applications, but more often than not, cutting back on crop nutrients means cutting back on profits.”
The problem of this practice, experts say, is that it leaves a lot of potential yield and profit lying dormant in the field.
Potash is a major source of potassium and helps plants develop strong root systems giving crops greater resistance to drought, disease, and insects. Phosphate is the major source of phosphorus, the energizer of plant production, which increases yields.
Nutrient Balance Trends Sources:
2.) AAPFCO: Fertilizer consumption data subtracted from the removal information to obtain a mass balance of nutrient levels for each year for each state. “Commercial Fertilizers 2014” is available; all earlier versions are still available. National fertilizer use data are available in a hard-copy publication, “Commercial Fertilizers 2014”, which is available from The Fertilizer Institute (TFI). The Association of American Plant Food Control Officials (AAPFCO), in partnership with TFI, has published the 2014 edition of the Commercial Fertilizer Report.
Percentage of Soils Below the Critical Level Sources:
International Plant Nutrition Institute: Data presented is based upon percent of samples testing below established critical levels for P and K for major crops in 2015. This includes results of P and K analysis performed on approximately 4.4 million soil samples. Critical Bray P1 equivalent levels for the soils and crops of the Great Plains and Corn Belt are usually around 20 ppm and increase to 25 to 50 ppm for the eastern U.S. Critical ammonium acetate K equivalent levels are generally in the 120 to 200 ppm range. Some crops may require substantially higher soil test levels than the critical level used in this analysis (consult your local university/agronomist for more information).
Important to Note: Soil testing is statewide and can differ within regions of every state and province. Nutrient management should occur on a site-specific basis where management objectives and the needs of individual fields and, in many cases, areas within fields, are recognized. Therefore, a general soil test summary like this one cannot reflect the specific needs of individual farms. Its value lies in calling attention to broad nutrient needs, trends, and challenges, and in motivating educational and action programs that are in turn relevant to growers and their advisers.