Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/16/2016
Publication Date: 8/23/2016
Citation: Lehman, R.M., Osborne, S.L. 2016. Combining agricultural practices key to elevating soil microbial activities [abstract]. International Society of Microbial Ecology, Montreal, Canada, August 21-26, 2016.
Technical Abstract: The concept of soil health is an emerging topic in applied ecology, specifically as it pertains to the agriculture, which utilizes approximately 40% of earth’s land. However, rigorous quantification of soil health and the services provided by soil organisms to support agriculture production (e.g., nutrient provision, pathogen and pest protection, etc.) is challenged by incomplete knowledge of the basic ecology of soil microbial communities and their functioning under various conditions. We conducted a replicated field study examining the effect of tillage (no-till vs. conventional till) and cover cropping (plus or minus) on soil microbial activities. A low-growing cover crop mix was inter-seeded into a corn/soybean rotation so that the ground was never barren of a living plant. We measured substrate-induced respiration (SIR) of a labile substrate (glucose) to represent root exudates and a more recalcitrant substrate (phenol) to represent soil carbon. At both depths sampled (0-10, 10-30 cm), SIR was higher under no-till compared to tillage. Under no-till, cover crops in the bean phase increased SIR with glucose and phenol as substrates (both depths) while only SIR with glucose increased under the corn phase (both depths). Under tillage, there were no differences in SIR with either substrate between the cover crop treatments. At both depths, SIR was higher under bean compared to corn. Our results indicate that shifts in the fundamental processing of organic substrates in the soil can be induced by combining agricultural management practices such as no-till and cover cropping.