USDA, Agricultural Research Service's (ARS) Northern Plains Agricultural Research Laboratory, in collaboration with the Soil Health Institute in N.C., evaluated the measurement of carbon dioxide flush—a rapid, reliable, and inexpensive method producers can use to measure soil health on dryland cropping systems—and refined it to be closely associated with most soil properties and long-term crop production.
Farmers, producers, and managers increasingly want to use soil health assessments to measure the level of desired properties in their soil, like soil aggregation, microbial activity, nutrient cycling, salinity, acidity, and organic matter. Generally, producers have to use several methods and indicators to measure many soil properties, and testing can become expensive.
Given that this knowledge can contribute to the decision-making of soil management practices for crop production, there is a need for an inexpensive and reliable test that can provide suitable data for measuring soil health, especially for nitrogen mineralization. Nitrogen mineralization is the amount of nitrogen that naturally becomes available from soil during a growing season, and knowing it can help farmers use less nitrogen fertilizer, still maintain crop yields, and reduce environmental degradation. Scientists are concentrating their efforts on identifying indicators and parameters for what makes a soil healthy, which can help producers to know if more practices could help them increase crop production while maintaining sustainable, healthy soil for generations to come.
One soil health indicator that scientists had focused on is the measurement of the carbon dioxide gas released (flushed) after rewetting of dry soils. The method involves adding water to a sample of dry soil and incubating for one day in a jar. The carbon dioxide released inside the jar during incubation indicates microbial activity in the soil. The higher the amount of carbon dioxide flush, the healthier the soil is.