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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #346004

Title: Soil CO2 response to organic and amino acids

item Haney, Richard
item HANEY, ELIZABETH - Texas Agrilife Research
item White, Michael
item Smith, Douglas

Submitted to: Applied Soil Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2017
Publication Date: 4/12/2018
Citation: Haney, R.L., Haney, E.B., White, M.J., Smith, D.R. 2018. Soil CO2 response to organic and amino acids. Applied Soil Ecology. 125:297-300.

Interpretive Summary: Farmers have an interest in planting cover crops as a way to improve the health of their soil and establish a better environment for possibly reducing the amount of synthetic fertilizers. We built a device that would allow the soil microbes to tell us the types of cover crops (food source) that would be best for a given soil. We accomplish this by feeding the soil microbes various foods and let them tell us which food types they like. We can then chose the appropriate cover crops mixes to encourage the growth of soil microbes which will in turn promote a more nutritious soil environment. We also believe we can use this instrument to better understand the food sources the soil microbes need under diverse soils from varying climatic regions under assorted management scenarios. We hope to develop an understanding of the myriad of compounds microbes assimilate to diversify organic matter within the soil.

Technical Abstract: Soil samples were obtained from under actively growing Austrian winter peas and from 2 m away in a plot that had no winter peas or other legumes growing in its cover crop mix. Soils were treated with 5 carbon compounds (oxalic, malic, citric, glycine and arginine) including a control (DI water) and their response was measured using an automated soil respiration system. The soil under winter peas evolved a higher amount of CO2 than the soil without winter peas across all treatments. The winter peas soil showed an increased response to oxalic and citric acids indicating that these compounds may be released by winter peas and that the microbial community is adept at assimilating them. We may be able to determine the C compounds and associated vegetation to which the indigenous microbial population is frequently exposed. Cover crop recommendations may be made based on microbial response rates in an effort to increase the diversity of the microbial community and health of the soil.