Soil Test System Is A Game Changer

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No-Wait Nitrate system

Precision technology has revolutionized practices throughout agriculture, from field guidance to application to planting. But while electronic connectivity and overnight delivery improved the soil testing process, there hasn’t been a major challenge to the way soil tests have been conducted since the proliferation of the dry test in the late 1980s.

A young company called Solum, Inc. is aiming to change that in the very near future. Founded by a group of Stanford physicists with ties to agriculture, Solum has devised a scalable, high-throughput technology for testing samples that are “field-moist” — not dried — using a system that is completely portable and wirelessly tethered to tech support.

Conducting tests using field-moist samples — essentially whatever moisture level the sample contains at removal — was the definitive method for soil testing prior to the precision agriculture movement and its emphasis on generating soil test data rapidly. The dry sample regimen proved simpler and less costly to proliferate, so soil moist sampling fell out of favor.

Solum’s technology brings together the speed of the dry sampling method with the improved analysis that field-moist sampling delivers.

“The field-moist process focuses on what the plant sees,” says Landon Morris, Solum’s vice president of business development and marketing. “So by using this method you get a more accurate and reliable result.

“We are taking all the logistical and operational challenges associated with field-moist sampling from 20 years ago and removing them from the equation,” he continues. “This is very scalable and very solution-oriented, and it works whether you are measuring potash, or phosphorus, or zinc or nitrogen. The same technology allows us to analyze all soil nutrients using the field-moist process.”

The scalability aspect has been designed for retailers who want to run their own lab tests. Using a water supply and a 110-volt power supply, the testing equipment is fully portable and self-contained. And running a sample is as simple as placing the soil in the machine and pushing the start button. Results are returned in minutes.

Nitrogen Now

Solum is working to bring a full range of testing capabilities to agriculture with its field-moist sample system, but its first priority has been to bring portable, in-the-field nitrogen testing to market.

Called the No-Wait Nitrate system, the system’s accuracy was equivalent to the standard cadmium reduction test in an independent study overseen by Robert O. Miller, affiliate professor at Colorado State University and technical director of the Agriculture Laboratory Proficiency Pro­gram early last year.

During the 2011 season, retailers, growers and consultants across the US field tested the No-Wait Nitrate system, with results that proved the concept. More than 11,000 field-moist samples were pulled and analyzed last year, truly putting the system through its paces.

The system provides a faster and more reliable method for spring applied or split nitrogen application regimens, and can also be used to monitor nitrogen mineralization and leaching. It’s possible for an application to be made the same day, virtually eliminating the potential for soil nitrate changes from the time the sample is taken and analyzed. Weather events that occur between the time the sample is taken and the results are returned can significantly alter the nitrate profile of a field. With No-Wait Nitrate, the sample is pulled and tested in the field in soil moist condition, and available nitrate results are returned in minutes.

Other Testing

Deficiencies in the currently accepted method of testing soil have generally resulted in an inaccurate characterization of nutrient availability. The act of drying the soil often affects the integrity of the sample. Morris says that other nutrient testing using the field-moist sample regimen is available now via the traditional “sample and send” method for less time sensitive nutrient samples such as potash, phosphorus and zinc.

In addition to nutrient content measurement, Solum is working on a new, promising data layer for precision practitioners to consider: Particle size distribution.

“We are challenging the status quo on soil texture,” says Morris. Using an apparatus called a laser diffractometer; soil slurry can be analyzed to get a measure of particle size distribution which would relate to factors such as water and nutrient holding capacity.

Still in the early stages of research, Morris says that they hope the new data will fit well in a total precision soil analysis. “We’re running tests on particle size distribution this summer and interpreting the data along with some other bits of information,” he explains. “It’s one piece of the puzzle, but we feel that how it relates to other data layers will have important implications.”

For more information, check out Solum’s website here.

Schrimpf is the Group Editor for the CropLife Media Group at Meister Media Worldwide, with full editorial responsibility for CropLife, CropLife IRON, Cotton Grower and PrecisionAg Special Reports.

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