Proper Soil Fertility Critical To Higher Yields

With input costs continuing to rise, experts fear that some growers will short change their crop’s yield potential by scrimping on needed nutrients. While it’s tempting for farmers to cut back to save money, it may be a costly move. A significant negative impact on crop yield is possible when crops are not fertilized properly.

Estimates made by the International Plant Nutrition Institute (IPNI) show that many growers in key production areas are not replacing the soil nutrients that have been removed by their crops. Yield short falls may occur if the nutrient deficits drop below

critical levels.

“The best and most accurate way for growers to know what nutrients will be needed by the crops they grow is to conduct a soil test,” says Dan Froehlich, Ph.D., Director of Agronomic Marketing for The Mosaic Company. “This management tool allows

growers to take much of the guesswork out of a soil fertility program and to ensure adequate levels of nutrients are available in certain fields.”

Today’s higher commodity prices offer growers the opportunity to take full advantage of a balanced soil fertility program. Because, in spite of the rather significant increase in crop nutrient prices over the last two years, fertilizing for optimum yields still produces a profitable return investment.

When looking at a corn example from the state of Iowa in 2007 that had a fertilizer program of 140 lbs. of nitrogen (N), 70 lbs. of phosphate (P) and 55 lbs. of potash (K) per acre for 180 bu/a corn following soybeans, the result was a 197 percent return for the fertilizer investment. And even with still higher fertilizer prices in 2008, this same program would generate a 160 percent return on the fertilizer investment.

“It is important for growers to minimize the number of decisions that result in short-term cost savings, but long-term cost increases,” Froehlich says. Successful farmers base input decisions on site-specific facts that help assure them that they will get optimum returns from dollars invested in inputs such as fertilizer. No matter what the economic or agronomic environment, farmers need to make the basics of a profitable crop production program a top priority.

Successful growers are using smart fertilizer practices. These growers are utilizing on-farm nutrient supplies and prioritizing fields and areas within fields as to which have the greater need for fertilization. They also are allocating money to the correct nutrients to create a balanced approach, which will maximize the effectiveness of all nutrients. And finally, these successful growers are continuously re-examining their current practices to ensure they are reaching their most profitable yields.

One common approach for making fertilization recommendations, especially for P and K, is called the “sufficiency” concept and is based only on the predicted crop response to each added nutrient. Fertilizer is applied only when there is a good chance that there will be a profitable response that year.

The other common approach to P and K fertilizer recommendations is the “build and maintenance” concept. This system is used on fields that have lower soil test levels. Nutrients are added in excess of the minimum crop requirement to build the nutrient concentrations in the soil to the point where they will not be limiting. Whatever the approach, growers need to consider the value of the crop and compare the costs of potential yield loss with the expenses associated with fertilization.

The quest for healthier lives and better diets in developing countries is the primary driving factor behind the increased global demand for fertilizer. This demand while likely to keep fertilizer prices higher, also points to the on-going need for expanded production and maximum yields. And, proper soil fertility is the foundation on which high yields are built.

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