The following research article developed by BioFlora’s team at the Integrated Life Science Research Center describes the clear benefits of rejuvenating your soil after depleting it with fumigation. Please share it with your PCA or call your BioFlora representative to arrange a visit or virtual GoToMeeting with our talented team if there are any further questions.
Executive Summary
The problem facing many growers is the loss of soil microorganisms after fumigation. Common fumigants like methyl bromide, chloropicrin, Telone and others have been shown to destroy beneficial microbial populations in the process of removing soil borne pathogens and pests.
This recovery period for soils may last from weeks to months, and some soil microbes never recover. There is also strong evidence of less and less microbial recovery the more a fumigant is used.
After fumigation, there are many microbial “home sites” in the soil that are empty and need to be filled. This is a chance to repopulate the soil with beneficial microbes. Not doing so results in lower microbe diversity and the potential overgrowth of damaging microbes that survive fumigation.
GO Isolates is an ideal choice after fumigation because it supplies a high diversity and population of beneficial soil microbes, including bacterial strains that protect plant and root defense systems. GO Isolates contains a diversity of carbon complexes that support the improved microbial community when applied to the soil.
The Problem
Loss of Soil Microbes due to Fumigation
Beneficial microorganisms in the soil are essential for sustaining the health of agricultural soil systems. These soil microbes make significant contributions to pathogen suppression, nutrient cycling, plant nutrient uptake, soil structure development and maintenance, and agricultural productivity. When the beneficial microorganisms are depleted or missing from the soil, there is:
• Increased plant disease and soil pathogens
• Decreased availability of nutrients to the plant
• Increased soil compaction and loss of soil
aggregates
• Increased water requirements and loss of water
holding capacity
Fumigation with methyl bromide (MeBr), chloropicrin (CP), Telone and others is used to control a wide-array of soil borne pathogens and pests. While there is variation in the impact of the fumigant to nontarget microorganisms, all fumigants destroy a portion of the beneficial microbial population.
Various studies, both in the laboratory and in the field, have found that all major nontarget groups of soil microbes are significantly impacted by MeBr and MeBr:CP. Soils fumigated with MeBr typically have a longer recovery period than those fumigated with Telone.
The recovery time for soil microbial community structure after fumigation extends for many weeks or months (a significant portion of the crop cycle) and some microbial groups never recover to the levels found before fumigation.
The soil microbial community biomass is significantly lower in fumigated soils at depths up to 30 cm (12 inches). Additionally, there is strong evidence of less and less microbial recovery the more years the fumigant is used.
The Solution
Apply Beneficial Microbes to the Soil
GO Isolates is an OMRI and CDFA listed product that contains a wide diversity of native beneficial soil microbes in addition to a complex of carbon diversity to support the microbial growth after the microbes are in the soil.
Studies have indicated that there is a difference in deleterious and beneficial rhizosphere colonizers following fumigation in strawberry rhizosphere fumigated and non-fumigated soils. This emphasizes the need to replenish the soil with beneficial soil microbes before the harmful microbes can colonize the plant roots.
A nitrogen flush is frequently observed after fumigation, the result of decomposition of the cells killed by the fumigant, which is used for recolonization of the soil by the survivors of the fumigation. There are many empty microbial “home sites” in the soil that are vacant and need to be filled.
This is a prime opportunity to supply the soil with beneficial microbes to repopulate the soil. Not doing so results in a lower diversity of microbes and potentially the overgrowth of undesirable microbes that are fumigant survivors. Additionally, these microbes require a carbon source for food.
The GO Isolates product is an ideal source for supplying agricultural soils with both a diverse beneficial microbial population as well as the diverse carbon complexes needed to support them once they are in the soil. The suggested application rate for GO Isolates is 10 gallons/acre applied 3 times after fumigation at 2-4 week intervals.
About Global Organics
Global Organics® Group (GOG) is an international, integrated life sciences company engaged in the development and manufacture of proprietary organic plant nutrition agricultural products and natural ionic minerals for Human and Animal health. For more than 40 years, GOG’s BioFlora® business has been committed to environmental sustainability through its efforts aimed at preserving our ecosystem while providing superior plant nutrient systems. Global Organics® continues to grow with a mission to enhance human and animal life, the vitality of plants and soils, as well as the restoration of the environment through their Mineral BioSciences® (MBS) division.
Located in Goodyear, Arizona, USA, GOG serves customers both locally and globally with the use of Green Acres, our 1,200acre research farm, as well as our USDA Permitted Integrated Life Science Research Center® (ILSRC).
For more information about Global Organics®, or to interview Managing Partner & CEO Luke Blotsky, please call 623-932-1522 or email Sarah Van Wyk at svanwyk@globalorganicsgroup.com. To learn more, visit www.globalorganicsgroup.com.
References and Supplemental Reading
1. P.C. Brookes, A. Landman, G. Pruden and D.S. Jenkinson, “Chloroform fumigation and the release of soil nitrogen: A rapid direct extraction method to measure microbial biomass nitrogen in the soil”, Soil Biology and Biochemistry, vol. 17. no. 6, pp. 837-842, 1985.
2. S.R. Dangi, J.S. Gerik, R. Tirado-Corbalá, and H. Ajwa, “Soil microbial community structure and target organisms under different fumigation treatments”, Applied and Environmental Soil Science, vol. 2015, article ID 673264, 8 pages.
3. S.R. Dangi, R. Tirado-Corbalá, J.S. Gerik and B.D. Hanson, “Effect of long-term continuous fumigation on soil microbial communities”, Agronomy, 2017, 7, 37, doi:10.3390/agronomy7020037.
4. A.M. Ibekwe, S.K. Papiernik, J. Gan, S.R. Yates, C.H. Yang and D.E. Crowley, “Impact of Fumigants on soil microbial communities”, Applied and Environmental Microbiology, vol. 67, no. 7, pp. 3245-3257, 2001.
5. F.N. Martin, “Development of alternative strategies for management of soilborne pathogens currently controlled with methyl bromide”, Annual Review of Phytopathology, vol. 41, pp. 325-350, 2003.
6. E.H. Ridge and C. Theodorou, “The effect of soil fumigation on microbial recolonization and mycorrhizal infection”, Soil Biology and Biochemistry, vol. 4, no. 3, pp. 295-305, 1972.
7. T. Yamamoto, V.U. Ultra Jr., S. Tanaka, K. Sakurai and K. Iwasaki, “Effects of methyl bromide fumigation, chloropicrin fumigation and steam sterilization on soil nitrogen dynamics and microbial properties in a pot culture experiment”, Soil Science and Plant Nutrition, vol. 54, pp. 886-894, 2008.