|Echevarria Laza, Haydee|
|CANO, AMANDA - Texas Tech University|
|SLAUGHTER, LINDSEY - Texas Tech University|
Submitted to: Plant Biology
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2019
Publication Date: 8/3/2019
Citation: Echevarria Laza, H.J., Cano, A., Cotton, J.E., Slaughter, L., Baker, J.T., Lascano, R.J., Emendack, Y., Acosta Martinez, V., Payton, P.R. 2019. Increased soil respiration and arbuscular mycorrhizal fungi under elevated [CO2] and soil sater deficit in a peanut agroecosystem. Plant Biology. Presentation.
Technical Abstract: Predicted increases in atmospheric [CO2], decreased availability of irrigation water and high ambient temperatures are challenges that will impact food production in coming decades. Peanut is an important food crop cultivated in semi-arid region and its symbiotic capability with both mycorrhizal fungi and N2 fixing bacteria make it a model crop for understanding the soil microbial community dynamic. This study investigated the effect of elevated [CO2] (650 ppm) and induced soil water deficit on the soil microbial component during two growing seasons in the Texas High Plains peanut production system consisted of Amarillo fine sandy loam soil. Microbial community size and structure were evaluated via ester-linked fatty acid methyl ester (EL-FAME) profiling. Soil metabolic activity was examined by measuring soil respiration with the LI-6400 (LI-COR Biosciences, Lincoln, NE) and ß-glucosidase activity, which is involved in cellulose degradation. Regardless of the soil-water deficit or plant growth stage, elevated [CO2] shifted the microbial community composition towards 46% more arbuscular mycorrhizae (AMF) compared to the ambient [CO2]. Elevated [CO2] did not significantly change ß-glucosidase activity; however, soil respiration increased by 82% during periods of soil-water deficit. Further, elevated [CO2] increased soil total carbon and nitrogen content (measured with LECO TruSpec CN) under limited soil water conditions, in agreement with the increase in AMF. Our results suggested that elevated [CO2] is most likely to increase AMF populations, soil total carbon and respiration. Further ecological studies are needed for understanding the long-term impact of these findings in a changing climate.