Development of soil microbial communities for promoting sustainability in agriculture and a global carbon fix
- Published
- Accepted
- Subject Areas
- Agricultural Science, Environmental Sciences, Soil Science
- Keywords
- Soil Microbial Communities, Fungal Bacterial Ratio, Carbon Sequestration, Sustainable Agriculture, Water Conservation, Pollution Reduction, Soil Fertility Development, Soil Carbon Respiration
- Copyright
- © 2015 Johnson et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Development of soil microbial communities for promoting sustainability in agriculture and a global carbon fix. PeerJ PrePrints 3:e789v1 https://doi.org/10.7287/peerj.preprints.789v1
Abstract
The goals of this research were to explore alternative agriculture management practices in both greenhouse and field trials that do not require the use of synthetic and/or inorganic nutrient amendments but instead would emulate mechanisms operating in natural ecosystems, between plant and Soil Microbial Communities (SMC), for plant nutrient acquisition and growth.
Greenhouse plant-growth trials, implementing a progression of soil conditions with increasing soil carbon (C) (C= 0.14% to 5.3%) and associated SMC population with increasing Fungal to Bacterial ratios (F:B) ( from 0.04 to 3.68), promoted a) increased C partitioning into plant shoot and plant fruit partitions (m=4.41, r2=0.99), b) significant quantities of plant photosynthate, 49%-97% of Total System New C (CTSN), partitioned towards increasing soil C c) four times reduction in soil C respiration (CR) as F:B ratios increased, starting with 44% of initial treatment soil C content respired in bacterial-dominant soils (low F:B), to 11% of soil C content respired in higher fertility fungal-dominant soils (Power Regression, r2=0.90; p=0.003).
Plant growth trials in fields managed for increased soil C content and enhanced SMC population and structure (increased F:B) demonstrated: a) dry aboveground biomass production rates (g m-2) of ~1,980 g in soils initiating SMC enhancement (soil C=0.87, F:B= 0.80) with observed potentials of 8,450 g in advanced soils (soil C=7.6%, F:B=4.3) b) a 25-times increase in active soil fungal biomass and a ~7.5 times increase in F:B over a 19 month application period to enhance SMC and c) reduced soil C respiration rates, from 1.25 g C m-2 day-1 in low fertility soils (soil C= 0.6%, F:B= 0.25) with only a doubling of respiration rates to 2.5 g C m-2 day-1 in a high-fertility soil with an enhanced SMC (F:B= 4.3) and >7 times more soil C content (soil C= 7.6%).
Enhancing SMC population and F:B structure in a 4.5 year agricultural field study promoted annual average capture and storage of 10.27 metric tons soil C ha-1 year -1 while increasing soil macro-, meso- and micro-nutrient availability offering a robust, cost-effective carbon sequestration mechanism within a more productive and long-term sustainable agriculture management approach.
Author Comment
This is a submission to PeerJ for review.