Farmers looking for ways to control crop production costs and add to their bottom line should use soil sampling as the basis for their crop fertility program. If the late harvest and early freeze last fall meant that soil sampling didn't get done, there's still time this spring to take samples for a 2015 crop fertility program.
"Profit margins will be tight over the next few years and farmers are being pressed to optimize their inputs in order to protect margins," says Dr. Jim Friedericks, lab manager at AgSource Laboratories in Ellsworth, Iowa. "Soil sampling is the foundation for a well-planned fertilizer management program and a tool for tracking your fertility program's long-term success. This works for soil samples taken in spring or in fall."
Little difference in results from spring vs. fall soil sampling
University research from Iowa and Minnesota shows little significant difference in spring and fall soil testing results. Friedericks notes that spring post-plant soil sampling is increasingly popular with AgSource clients. The key, he says, to any sampling program is consistency in terms of timing year-after-year.
For example, if you are comparing soil test results over a period of years, you want to compare the soil test results of spring sampling in one year with the test results of spring sampling in another year. Or compare fall sampling soil test results in one year with fall sampling soil test results in another year.
If you are sampling in spring, keep in mind that post-plant soil sampling generally takes place May through June, and testing just the top 6 inches of soil during the early growth of the crop is recommended, he says.
Several benefits to spring sampling of soil compared to fall
"While there are seasonal and annual variations whenever we sample soil, experience at AgSource suggests several benefits to spring sampling," says Friedericks. "This includes the ability to get better core consistency when you probe soil in spring. Also, by sampling soil in spring, you avoid delays in fall fertilizer application after harvest."
"Also, keep in mind that we never can have too much data when soil testing," he adds. "Our ability to predict what's in between your sampling points increases, as you take more samples in a field. Good sample collection begins the process of getting accurate soil test results that reflect what's happening in the field. A good soil sampling plan is something farmers should insist on from their crop consultants and agronomists or whoever does the sampling. Once you get an accurate set of soil samples taken, laboratory quality assures accurate testing results. And our AgSource laboratories can deliver that quality."
For more information on soil sampling, soil analysis and quality soil testing results go to agsource.com/laboratories. AgSource is a leader in ag and environmental laboratory analysis and information management services, with facilities in Iowa, Nebraska, Oregon and Wisconsin. A division of Cooperative Resources International, AgSource Labs provides testing services to clients in the U.S. and across the globe.
Use soil sampling and testing to capture these benefits
Growers should use soil testing as a tool for making scientifically sound management decisions about their soil fertility program, says Friedericks. A fertility program based on information from soil test results can benefit a farmer in the following ways:
• improved yields and profitability from providing needed nutrients for the crop
• opportunity to increase the uniformity of nutrient availability across a field, so that optimum response to other management inputs can be achieved
• more uniform crop growth which makes the individual plants more competitive with weeds and simplifies other management practices such as cultivation, spraying, etc.
• more uniform maturing dates for all plants within a field simplifies harvesting and drying of crops, and potentially improves market quality
• Fertilizer dollars can be allocated to the nutrients that will give the greatest return in profit. With intensive sampling and variable-rate fertilizer application technology now available, there is increased potential for fine-tuning fertilizer applications within a field.