Mexico Corn - Demonstrating a Soil Microbiological Approach

Project Type

Project Summary

Doug Weatherbee, soildoctor.org, conducted a yield trial of two corn fields during the summer of 2009, when Mexico was experiencing its worst drought in 68 years. During this time, dryland farmed corn failed all over the country. The difference between microbiological treated organic corn and a field of non-treated organic corn demonstrates the benefits of microbiological farming.

Project Description

Doug Weatherbee, soildoctor.org, conducted a yield trial of two corn fields during the summer of 2009, when Mexico was experiencing its worst drought in 68 years. During this time, dryland farmed corn failed all over the country. The difference between microbiological treated organic corn and a field of non-treated organic corn demonstrates the benefits of microbiological farming.

Control non-treated organic corn: Sept. 18/09

Microbiological treated organic corn: Sept. 18/09

Control non-treated organic corn

Microbiological treated organic corn

Side by Side Average Cobbs at Harvest

Control cob on left …… Biological cob on right

As mentioned dryland-farmed corn has failed in many parts of the Mexico in 2009 including the area in which this yield data is based.  Here is some yield data comparisons between the ‘control’ field and the micro-biologically managed field.

Carbon Farming

Not Often Talked About Labile Soil Microbial CO2

Usually when we talk about Carbon sequestration in the soil we are referring to the increase in tough Carbon rich soil organic matter such as microbially produced humus and glomalin. These forms of soil Carbon are recalcitrant or long lasting and hard to break down forms of soil Carbon.

Microbes, particularly fungi, are directly involved in producing the recalcitrant humus and glomalin soil Carbon. Often agricultural fields have low amounts of fungi and often the goal of a microbiological farming approach is to increase the fungal amounts in the soil. The are multiple ways to increase fungal amounts which often include getting more Carbon rich organic matter into our field (no-till cover crop cocktails with Carbon rich grasses - Rye for example). These Carbon rich organic matter cover crop plants, when killed through seasonal change or mechanical methods like the Rodale crimper, are fungal food right in the field (think humification composting right in the field, above and below ground). Eventually the fungi produce the stable humus and glomalin from this Carbon rich organic material. So microbes, particularly fungi, are a key part of soil Carbon sequestration.

An interesting but not often talked about feature of using a microbiological farming approach is that as you dramtically increase the numbers of soil microbes, including fungi, you are increasing the total weight or biomass of microbes per acre or hectare.  The bodies of all the microbes contain Carbon and by measuring the increasing microbial biomass you can calculate the increase in CO2 sequestering in the bodies of the microbes.  This soil microbial body Carbon is not considered stable or recalcitrant but labile or short term forms of soil Carbon.  Conditions in the soil could change dramatically (such as tillage or field cultivation) and kill mainy microbes, particulary fungi, resulting in the dead microbial bodies being decomposed by other microbes and oxidised into CO2 and released into the atmosphere.

So in addition to all the benefits of having a healthy large number of microbes in our soil for the health of our plants and the ability of the soil to make stable forms of Carbon, we also have Carbon stored in the very bodies of the living active and dormant microbes.  We can start to see that taking care of and feeding the various soil microbes is key to Carbon farming and regenerative agriculture. 

As part of the data collected on the control and microbiological Mexico corn fields I had the Soil Foodweb Lab in Oregon measure the microbial biomass at different points in the growing season.  I then calculated the CO2 change from beginning of season (May) to near end (September). Interesting soil Caron sequestration results to think about:

Updates