Soil microbial diversity and C turnover modified by tillage and cropping in Laos tropical grassland

• DOI: 10.1007/s10311-013-0420-8
• Publication Date: 2013-05-07T11:10:33Z
• Authors: Pascal Lienhard; Sébastien Terrat; Olivier Mathieu; Jean Levêque; Nicolas Chemidlin...; Virginie Nowak; Tiffanie Régnier; Céline Faivre; Sengphanh Sayphou...; Khamkéo Panyasiri; Florent Tivet; Lionel Ranjard; Pierre-Alain Maron
• Keywords: Microbial diversity; F08 - Systèmes et modes de culture; agroécologie; biodiversité; labour; http://aims.fao.org/aos/agrovoc/c_33990; http://aims.fao.org/aos/agrovoc/c_2018; sol acide; Priming effect; [SDV.SA.SDS] Life Sciences [q-bio]/Agricultural sciences/Soil study; http://aims.fao.org/aos/agrovoc/c_8511; F07 - Façons culturales; 2. Zero hunger; http://aims.fao.org/aos/agrovoc/c_33949; prairie; non-travail du sol; Carbon cycle; 04 agricultural and veterinary sciences; travail du sol; rotation culturale; http://aims.fao.org/aos/agrovoc/c_92381; http://aims.fao.org/aos/agrovoc/c_89; http://aims.fao.org/aos/agrovoc/c_7771; P33 - Chimie et physique du sol; cycle du carbone; Conservation agriculture; http://aims.fao.org/aos/agrovoc/c_7172; [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study; Tillage; Acid savannah; http://aims.fao.org/aos/agrovoc/c_12076; biologie du sol; savane; http://aims.fao.org/aos/agrovoc/c_6154; pratique culturale; flore du sol; P35 - Fertilité du sol; http://aims.fao.org/aos/agrovoc/c_7160; P34 - Biologie du sol; 15. Life on land; [SDE.BE] Environmental Sciences/Biodiversity and Ecology; expérimentation au champ; http://aims.fao.org/aos/agrovoc/c_6825; 0401 agriculture, forestry, and fisheries; http://aims.fao.org/aos/agrovoc/c_17299; http://aims.fao.org/aos/agrovoc/c_6021; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; http://aims.fao.org/aos/agrovoc/c_6662

Agricultural practices should modify the diversity of soil microbes. However, the precise relationships between soil properties and microbial diversity are poorly known. Here, we study the effect of agricultural management on soil microbial diversity and C turnover in tropical grassland of north-eastern Laos. Three years after native grassland conversion into agricultural land, we compared soils from five land use management systems: one till versus two no-till rotational cropping systems, one no-till improved pasture and the natural grassland. Soils were incubated in microcosms during 64 days at optimum temperature and humidity. Bacterial and fungal diversity were evaluated by metagenomic 454-pyrosequencing of 16S and 18SrRNA genes, respectively. Changes in soil respiration patterns were evaluated by monitoring 12C- and 13C-CO2 release after soil amendment with 13C-labelled wheat residues. Results show that residue mineralization increased with bacterial richness and diversity in the tilled treatment 7 days after soil amendment. Native soil organic C mineralization and priming effect increased with fungal richness and diversity in improved pasture and natural grassland. No-till cropping systems represented intermediate situations between tillage and pasture systems. Our findings evidence the potential of controlling soil microbial diversity by agricultural practices to improve soil biological properties. We suggest the promotion of no-till systems as a fair compromise between the need for agriculture intensification and soil ecological processes preservation.