Differential responses of structural and functional aspects of soil microbes and nematodes to abiotic and biotic modifications of the soil environment

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment ecosystems & environment, 2012-10, Vol.61, p.26-33
• Main Authors: Papatheodorou, E.M., Kordatos, H., Kouseras, T., Monokrousos, N., Menkissoglu-Spiroudi, U., Diamantopoulos, J., Stamou, G.P., Argyropoulou, M.D.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; bacterial communities; Biological and medical sciences; biomass; Chemical, physicochemical, biochemical and biological properties; Ecoplates; edaphic factors; functional diversity; functional response; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Irrigation; Manure application; Mediterranean soils; Nematoda; Nematode trophic guilds; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Phospholipid fatty acids; Physics, chemistry, biochemistry and biology of agricultural and forest soils; soil nematodes; Soil science; soil structure; Soil-plant relationships. Soil fertility. Fertilization. Amendments; water supply; wheat
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2012.04.002

► We compared the effect of abiotic vs biotic environmental changes on soil communities. ► Water vs manure supply differently affected PLFA, CLPP microbial profile, nematodes. ► The PLFA microbial structure was mainly regulated by water supply (abiotic treatment). ► Treatments did not affect the CLPP profile due to the microbial functional redundancy. ► Nematode response was occasional, relating to manure rather than to water supply. We evaluated the effect of an abiotic and a biotic modification of soil environment on the structure and function of soil biological communities in a six month experiment established in a recently abandoned wheat field. Evaluations included PLFA and CLPP microbial profile as well as the nematode trophic structure and functional indices in plots that differed in irrigation (abiotic modification) and manure application (biotic modification). Four treatments were created: low water supply-manure fertilization, low water supply-no fertilization, high water supply-manure fertilization and high water supply-no fertilization. Two samplings were carried out: the first after 8 weeks of irrigation (March) and the second after 20 weeks (June). The PLFA groups were mainly affected by the abiotic treatment (water supply), which acted either alone in June or in combination with the biotic treatment in March. In all plots, there was an increase of bacterial and to a lesser extent of fungal biomass from March to June, as well as a shift of the bacterial community towards Gram+. The microbial catabolic profile was different in the two sampling occasions, whereas the microbial functional diversity (Shannon index) was not affected either by treatment or by sampling time. Nematode abundance was also higher in June in relation to March in all plots, whereas the response of nematode feeding groups to treatments was occasional and related to manure rather than to water supply.