Impact of long-term N, P, K, and NPK fertilization on the composition and potential functions of the bacterial community in grassland soil

Abstract

Soil abiotic and biotic interactions govern important ecosystem processes. However, the mechanisms behind these interactions are complex, and the links between specific environmental factors, microbial community structures, and functions are not well understood. Here, we applied DNA shotgun metagenomic techniques to investigate the effect of inorganic fertilizers N, P, K, and NPK on the bacterial community composition and potential functions in grassland soils in a 54-year experiment. Differences in total and available nutrients were found in the treatment soils; interestingly, Al, As, Mg, and Mn contents were variable in N, P, K, and NPK treatments. Bacterial community compositions shifted and Actinobacteria were overrepresented under the four fertilization treatments compared to the control. Redundancy analysis of the soil parameters and the bacterial community profiles showed that Mg, total N, Cd, and Al were linked to community variation. Using correlation analysis, Acidobacteria, Bacteroidetes, and Verrucomicrobia were linked similarly to soil parameters, and Actinobacteria and Proteobacteria were linked separately to different suites of parameters. Surprisingly, we found no fertilizers effect on microbial functional profiles which supports functional redundancy as a mechanism for stabilization of functions during changes in microbial composition. We suggest that functional profiles are more resistant to environmental changes than community compositions in the grassland ecosystem.

Land-use system shapes soil bacterial communities in Southeastern Amazon region

“…In this study, we may assure that the preparation of soil for soybean crop was the main cause of the difference in pH between soils. However, not only pH correlated with the structure of microbial communities in these soils, showing that other soil parameters are important in shaping the communities, as shown by others (Faoro et al, 2010;Jesus et al, 2009;Kuramae et al, 2012;Lauber et al, 2008;Mendes et al, 2014;Navarrete et al, 2013;Pan et al, 2014). Our results show that Al saturation index and Al were the factors that presented correlation with more number of bacterial phyla.…”

“…Also, the long-term effect of land-use change on microbial communities is of paramount importance and is ultimately required for evaluating sustainability of different management systems (Rasmussen et al, 1998). Yet few studies have been conducted in agroecosystem in an extended period of time (Hartmann et al, 2015;Pan et al, 2014) and this information will stimulate the development of better soil management strategies focused on minimizing the environmental perturbation in order to promote sustainability.…”

Land-use changes influence soil bacterial communities in a meadow grassland in Northeast China

“…The potential causes of this correlation are the following: (1) integration of pH with other soil physical, chemical, and microbiological properties and (2) a slight variation in the soil pH that could expose microbes to stress, or in other words, the sensitivity of the microbial cell to environmental change (Fierer and Jackson, 2006). Some studies indicated that several parameters other than pH and elements (e.g., Mg, Al, and Cd) are also correlated with specific bacterial groups and structural alternation of microbial communities (Pan et al, 2014;Jesus et al, 2009;Mendes et al, 2015). The vegetation cover might affect the diversity and structure of the soil microbial community because the differences in plant community compositions can contribute to changes in litter quality and quantity, which then alter the content and cycling processes of soil nutrients (Miki et al, 2010).…”

Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe

“…Although previous studies have shown that soil microbial communities can shift in response to nutrient additions at individual grassland sites (18,20,22,24), relating these taxonomic or phylogenetic shifts to changes in the functional attributes of these communities is not trivial. Simply documenting how communities shift in composition might not tell us how the aggregated traits of these communities change in response to nutrient additions because soil microorganisms are incredibly diverse, and most soil microbial taxa remain uncharacterized (25).…”