The match between microbial community structure and soil properties is modulated by land use types and sample origin within an integrated agroecosystem

Abstract

It is of global concern to adopt measures to mitigate land degradation caused by agricultural production systems. One of the strategies proposed is to replace degraded pastures with agrosilvopastoral systems which integrate three different land-use types: crop production, livestock pasture and forestry plantation (denoted iCLF). However, little is known about the differences between iCLF and other land use types in terms of soil microbial community structure. Distance matrices based on individual soil chemical properties and individual soil microbial variables were correlated by Procrustes analysis and these relationships yielded vectors of residuals depicting these correlations (matches). These vectors were used as univariate response variables in an ANOVA framework in order to investigate how the match sizes (the strength of correlation/covariance) between individual soil chemical properties and individual soil microbial variables vary across land use types (levels: iCLF; degradated pasture; improved pasture; and a native cerrado fragment) and also across sample origin within iCLF (levels: soil samples under more influence of the exotic tree forest stand; soil samples under influence of the pasture; samples within the transition between the forest stand and the pasture). We were able to obtain insights into the fact that the land use distinction can be driven by more than just individual soil chemical and microbial variables. The integration of crop, livestock and forestry promoted a dominance of fungi in this low fertility and low pH environment. P availability and the composite variable exchangeable base cations (Ca þ2 , Mg þ2 , K þ) were the soil properties whose strengths of correlation (match sizes) with individual microbial variables were the most affected by land use type and sampling origin within iCLF. While the strength of the correlation between soil microbial structure variables and P availability was typically land use type dependent, the response of the microbial structure to exchangeable base cations was mainly affected by the sample origin within iCLF. Finally our results point towards the conclusion that increases in the heterogeneity of vegetation within integrated crop, pasture and forestry systems are an important driver of microbial community response to environmental changes, and may be one means by which to increase the sustainability of tropical agroecosystems.

Variation of arbuscular mycorrhizal fungal communities along an altitudinal gradient in rupestrian grasslands in Brazil

“…Furthermore, at this low altitude, the highest amount of the nutrients K and P and an increase in pH were recorded. Generally, the availability of these nutrients reflects a lesser colonization of AMF in plant species and lower spore density (Abbott and Robson 1991), corroborating the hypothesis that plant species benefit from the symbiosis with AMF in low fertility environments (Berbara et al 2006;Miranda 2008;Moreira et al 2010;Lisboa et al 2014).…”

Biological Soil Properties in Integrated Crop-Livestock-Forest Systems

“…These iCLFs are designed to have a different microbial structure from that of degraded pastures due to the greater diversity of their microbial community. However, the structure of this community is rarely investigated in integrated systems such as the iCLF, especially in the tropics (Lisboa et al, 2014). Thus, little information is available on the effects of increased species diversity on soil biological quality.…”

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

“…Therefore, the real factors were easily masked by other dependent factors. Second, the studies were conducted under different land use type in broad region which possibly could produce the various relationships between microbial communities and soil properties (Lisboa et al, 2014;Williams et al, 2013). Due to the decrease in bacteria, the fungal/bacterial ratio increased significantly after conversion (Fig.…”

“…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). The development of different plant species associated with land use conversion would have different influences on soil microbial communities in the rhizosphere, which depends on the differences in the quantity and quality of carbon resources different plant species produce (Sanon et al, 2009).…”