Soil sampling is a complicated science. Not only is every year different, but planters can be certain that weather, environment and technology play important factors in fertilization practices, according to industry experts.
Farmers should know that it’s critical to obtain an adequate number of soil samples to constitute a composite, according to Dr. Robert Mullen of Nutrien. “If you do not, you can get squiffy information. And squiffy data is not useful data.”
However, sampling every grid point, Mullen says, is not always practical or cost effective. He says that the goal of soil sampling is “attempting to estimate the average soil test within a given area.”
Mullen spoke on soil sampling and precision at the second annual Precision University Conference on Thursday at Beck’s Hybrids in London. The conference theme was Nutrient Management and was hosted by The Ohio State University College of Food, Agricultural, and Environmental Sciences, along with the University Extension and the Digital Agriculture program team.
Mullen posed the question: does precision matter? The “precision” in Precision University focuses on precision technology, cutting-edge machinery that ensures work on the farm is done with accuracy.
“Utilizing precision ag is a tool for making better nutrient decisions at the farm level,” said Mullen.
Mullen was not the only one who had some insight on nutrient technology at the conference.
Dr. Brian Arnall of Oklahoma State University believes that “we do not, period, do enough on-farm testing.”
“We need to find a way that our recommendations are just as precise as our data,” said Dr. Arnall. He says that otherwise the data “collected from a 300 by 300 foot area” is no good when compared to the value for the state of Ohio.
He suggests finding points in the field and watch and adjust the arrangement based on what the soil and plants are doing. “Our sampling either has to become more dense in space or time,” said Dr. Arnall.
Jamie Bultemeier of A&L Great Lakes claims that it takes three data points to get an average, but it takes four to get a trend. Farmers won’t always find it practical to sample throughout the year, such as pulling five samples per year. “But if we can,” said Bultemeier, “then we can perhaps catch problems earlier.
Mineralization and timing are vital to applying nutrients, such as nitrogen and potassium, two focal topics throughout the featured speakers’ presentations.
“This may be a shocking statement, but every year is different,” said Jim Swartz of Beck’s Hybrids. He emphasized how hard it is to do research on nitrogen because of this reason. The average can change with the different years.
He asked, “Why do we treat them all the same with nitrogen?” He says that the problem with nitrogen is that it is so variable, and the weather can impact the variable dramatically. Hybrids also respond differently to different nitrates. Many factors come into play when it comes to deciding how much nitrogen to apply.
Swartz compared various starter placement systems to determine the usage of products that farmers might not otherwise use. Choosing the right technology and program will vary with every farmer’s situation.
Farmers have many choices regarding how to apply nitrogen, says Dr. Tony Vyn of Purdue University, such as pre-plant, side-dressing and late side-dress as a supplement. However, 90 percent of potassium is already in the plant by the time it flowers.
Vyn cautions farmers, “Those two [nitrogen and potassium] together are toxic…be careful not to apply in spring program where you’re applying less than a week before planting, make sure you do not apply nitrogen with ammonia and K20 at anything like rates at 150 or more.”
The nutrient management conference also hosted a variety of agriculture company booths and a discussion panel about equipment and technology, including panelists: Dr. Scott Sherear, The Ohio State University; Nate Douridas, Molly Caren Farm; and Lee Radcliff, Radcliff Farms. For more information on Ohio State Precision Agriculture visit: www.fabe.osu.edu/programs/precisionag.
Amanda Rockhold is a staff writer for Rural Life Today. She can be reached at 740-852-1616, ext. 1617.