microBIOMETER® testing for soil health and yield stability

Nature article reports that microbial biomass estimates by microBIOMETER® correlates with soil health and yield stability.

The microBIOMETER® soil test was used to report microbial biomass in a recent Nature publication*. Scientists Dr. Judith Fitzpatrick and Dr. Brady Trexler of microBIOMETER® collaborated with a University of Tennessee team headed by Dr. Amin Nouri. The team evaluated the effects on soil health and yield stability of 39 different methods of raising cotton over 29 years. The conditions tested included till, no-till, various cover crops and different levels of nitrogen fertilization.

The study found that the major impacts on yield were very dry or wet conditions, and low or high temperatures. The deleterious effects of these weather extremes on yield were mitigated by regenerative agricultural practices which resulted in adequate soil, C, N, soil structure and microbial biomass.

Conservation agriculture increases the soil resilience and cotton yield stability in climate extremes of the southeast US

*Nouri, A., Yoder, D.C., Raji, M., Ceylan, S., Jagadamma, S., Lee, J., Walker, F.R., Yin, X., Fitzpatrick, J., Trexler, B. and Arelli, P., 2021. Conservation agriculture increases the soil resilience and cotton yield stability in climate extremes of the southeast US. Communications Earth & Environment, 2(1), pp.1-12.

What is “priming” and how does it affect your soil?

Priming is currently a hot topic as it affects whether the fertilizer you are using is effective. For instance, when you prime a pump, the water you add allows the pump to start pumping water. If there is not enough water, you just wasted the priming water.

This is exactly what happens in your soil. When the microbes in the soil are fed nutrients “primed”, by the plant or amendment, it wakes them up and they start growing. But, whether they can continue to grow depends on the continual supply of nutrients. If there is enough balanced organic matter in the soil, they are fine. If not, the microbes will work hard to harvest some of the stored carbon, nitrogen and phosphorus in the soil. And instead of storing carbon in the soil, their labors will produce CO2.

A key point is “balanced” nutrition available in the fresh organic matter which is most available to microbes. Like us, if microbes do not have access to one of the key nutrients, e.g. N, P, S, K, Mg, Mn, B, etc. they cannot thrive. Clive Kirby’s group in Australia has demonstrated that by balancing the ratio of key nutrients in fertilizer regimens to bring the ratio of fresh organic matter to a C:N:P:S ratio of 10,000:261:32:48 they increased yield and substantially increased the stored soil carbon.

Source: Coonan, E.C., Kirkby, C.A., Kirkegaard, J.A., Richardson, A., Amidy, M. and Strong, C., 2020. Microorganisms and nutrient stoichiometry as mediators of soil organic matter dynamics. NUTRIENT CYCLING IN AGROECOSYSTEMS, 117(3), pp.273-298.