Anna Yang Junli Hu Xiangui Lin Anning Zhu Junhua Wang Jue Dai Ming Hung Wong. Arbuscular mycorrhizal fungal community structure and diversity in response to 3-year conservation tillage management in a sandy loam soil in North China. J Soils Sediments 2012 12:835–843.
Abstract
Purpose Modern agricultural science has greatly reduced the use of tillage. Monitoring conservation versus conventional tillage effects on soil microbes could improve our understanding of soil biochemical processes and thus help us to develop sound management strategies. The objective of this study was to investigate the effects of conservation tillage on the spore community structure and the diversity of soil arbuscular mycorrhizal (AM) fungi and to find out the main factors that influence these parameters.
Materials and methods A long-term field experiment established in a sandy loam soil in Northern China has received continuous tillage management treatments for 3 years including conventional tillage (CT) no tillage (NT) and alternating tillage (AT). Topsoil samples (0–15 cm) from four individual
plots per treatment were collected for the analysis of chemical properties and fungal parameters. AM fungal spores were isolated using the wet-sieving method and identified to species level based on morphology by light microscopy. The community structure and the diversity of AM fungi were evaluated using the following parameters: spore density relative abundance species richness Shannon–Wiener index (H′) evenness (E) and Simpson’s index (D). Jaccard index (J) of similarity was calculated to compare AM fungal species composition under different treatments.
Results and discussion Twenty-eight species of AM fungi within four genera Glomus Acaulospora Scutellospora and Entrophospora were recovered from the 12 plots within the three tillage management treatments. Higher spore density species richness and species diversity (H′ E and D) of AM fungi were observed in the two conservation tillage treatments and the redundancy analysis showed that the species richness significantly correlated to soil organic carbon content (P<0.05). The positive effects of NT and AT on the species richness were very close while the AT had relatively greater beneficial impacts on the spore density and the evenness of AM fungi compared to the NT. The lowest Jaccard index (J) of similarity in species composition was also observed between the AT and CT treatments.
Conclusions Soil organic carbon the spore density and species richness and diversity of AM fungi increased in the two conservation tillage treatments. The species richness of AM fungi significantly correlated to soil organic carbon content (P<0.05). Compared with the CT treatment the AT rather than the NT significantly increased the spore density and the evenness of AM fungi (P<0.05). Thus alternating tillage practice may be more beneficial to agroecosystem in this region.
