Source: Woods End Laboratories

Woods End Laboratories, manufacturer of laboratory-based soil respiration and amino-nitrogen soil tests, has announced the release of the Solvita Field Test, which enables growers and crop consultants to conduct on-site evaluations of soil biology without the added expense of sending samples to a laboratory.

As growers have become more interested in biological soil fertility — more commonly known as “soil health” — measuring soil carbon dioxide respiration in the field has become important as a way to gauge the quality of the soil’s biology. This measurement is also significant for a reason that has been overlooked until recently: It provides a way to track how much carbon dioxide the plants are receiving.

Plants have a large appetite for carbon dioxide, particularly mid-summer. They extract carbon dioxide from surrounding air to form basic sugars through photosynthesis. During the most rapid growth, however, carbon dioxide can be a limiting nutrient. This means yields are saturated at lower than potential levels.

“It would take 12-38 cubic acres of air to provide enough carbon dioxide for an acre of wheat and corn,” says Will Brinton, inventor of Solvita. “We commonly assume plants just somehow get all this from the air but the fact is much is coming directly from soil due to microbial respiration.”

Brinton has presented multiple lectures and NRCS webinars discussing early Swedish studies that demonstrate plants can get all their carbon dioxide from biologically fertile soils, but not when the soil is biologically depleted. His findings show that the microbe respiration rate measured in the field can indicate when the soil is providing sufficient level carbon dioxide for healthy high-yield growth.

“Basal respiration expresses the total activity of bacteria and fungi living in the soil,” Brinton explains, “and this reflects the system’s balance of soil organic matter, the primary source of carbon dioxide, which diffuses out of soil. With the Solvita Field Test, growers can accurately monitor this rate and make observations that can affect future organic matter applications and yield.” 

Test results may be compared to tables provided in the Solvita manual and to online resources for calculating carbon dioxide rates and biomass, which indicate the significance of crop carbon dioxide demand.

How the Field Test is Different from One Performed in a Lab
This test was developed so that growers or crop consultants in the field can obtain results with a few simple steps. The Solvita Field Test enables the user to put a moist soil sample in a jar, insert a probe, let it set for 24 hours and then check the probe’s color against a color chart or with a digital color reader (handheld spectrometer). The results indicate a carbon dioxide value that shows how many pounds of carbon dioxide per acre the soil microbes are releasing (directly related to crop growth). From this one can estimate how much organic nitrogen and phosphorous are likely to be released from the organic matter in the soil due to microbes “feeding” on it.

The Solvita Field Test includes:

  • Field Version Digital Color Reader (Spectrometer)
  • 25 Solvita Probes
  • Miniature Digital Balance (to weigh soils)
  • Incubation Jars
  • Interpretation Guide

Complete Soil Health Lab Testing
Growers still wishing to get a complete, professionally integrated view of soil biology as it influences nutrients may obtain Soil Health Test results by sending soil samples to Woods End Laboratories or one of the many soil test labs across the country using Solvita products. Use the Soil Solvita map to find the lab nearest you. For instructions on sending samples to Woods End, email and check “The Soil Health Test” link.