Responses of microbial community structure to land-use conversion and fertilization in southern China

Abstract

a b s t r a c tA short-term experiment was carried out in southern China to investigate the effects of land-use conversion from rice paddies to vegetable fields and fertilization on soil microbial community structure by analyzing soil phospholipid fatty acid (PLFA) profiles. A split-plot design with four replicates was adopted, in which land use (paddy and vegetable field) was the first-level treatment and fertilization (conventional fertilization and no fertilization) was nested as the second level. Our results showed that both land-use conversion and fertilization had significant effects on microbial community structure. After 2 years of land-use conversion, the total amount of PLFAs were 3.54 and 2.97 nmol g À1 for fertilized (VeF) and unfertilized (VeNF) vegetable fields, respectively, and 3.19 and 2.32 nmol g À1 for fertilized (R eF) and unfertilized (ReNF) rice paddies, respectively. Soil fungal PLFAs were 1.04 and 0.87 nmol g À1 for VeF and VeNF, respectively, which were significantly increased by 13.9 and 11.4 times compared with those of ReF and ReNF, respectively. The ratio of fungal to bacterial PLFAs significantly increased in vegetable fields compared with rice paddies. No significant differences were found in the total, bacterial, and actinomycetic PLFAs between vegetable fields and rice paddies. The application of fertilizer significantly increased the amount of total PLFAs and bacterial PLFAs. With land-use conversion and fertilization, soil physicochemical properties also changed, and microbial community structure showed a significant relationship with soil water content, NH 4 þ -N, and pH, which explained the land-use conversion and fertilization effects on soil microbial community composition.

Changes of anaerobic to aerobic conditions but not of crop type induced bulk soil microbial community variation in the initial conversion of paddy soils to drained soils

“…4). This is consistent with the results presented by Yuan et al (2015). It was noted that a higher fungal/bacterial ratio indicated better sustainability because fungi have a greater growth yield efficiency compared with bacteria, and thus have slow C turnover (Thiet et al, 2006).…”

“…In accordance with our first hypothesis, the recent conversion from paddy fields to drained fields significantly changed the soil properties. These influencing patterns and extents on soil properties were similar for conversed MM and SP, which confirms the role of land use conversion (from paddy fields to drained fields) in altering soil properties (Darilek et al, 2010;Yuan et al, 2015). It was obvious that the soil water content decreased significantly after conversion from RR to MM and SP (Table 1), even though the soil samples were collected at crop harvest after the rice fields had been drying.…”

“…Previous studies have shown that shifts in the soil microbial community structure can be associated with changes in a number of soil properties, including the soil water content Yuan et al, 2015), the soil total phosphorus, available phosphorus (Sheng et al, 2013), NO 3 -N, and soil organic carbon contents, pH (Sheng et al, 2013;Yang and Zhang, 2014;Yuan et al, 2015), and so on. The different relationships between microbial communities and soil properties are mainly affected by land use type and land use history (Lisboa et al, 2014) and has been shown to be site-specific (Williams et al, 2013).…”

Response of soil nematode community composition and diversity to different crop rotations and tillage in the tropics

“…They concluded that the crop rotation provides better soil hydrological conditions, effective rhizodepositions and residual fertility which usually stimulate high proportion of soil microorganisms. Yuan et al (2015) also suggested that the differences in quantity, quality and distribution of papaya residues generally lead to greater concentrations and diversity of organic materials, and thus, to higher soil microbe viability, and accelerated carbon and nutritional cycling compared with pineapple and rice. In tillage systems, the abundance of primary decomposers, such as bacteria and fungi was much greater in NT than in CT, which was instantiated by the higher abundance of bacterivores and fungivores in NT compared with CT ( Fig.…”

Effects of land use conversion and fertilization on CH4 and N2O fluxes from typical hilly red soil

“…The topsoil (0-10 cm) has an organic carbon content of 9.40 g kg −1 and total N content of 1.00 g kg −1 . The soil pH was 4.99, and the bulk density was 1.30 g cm −3 (Yuan et al 2015).…”