The Impact of Pasture Systems on Soil Microbial Biomass and Community‐level Physiological Profiles

Abstract

The intensive use of soil for pasture establishment has promoted land degradation. However, well-managed pasture systems may contribute to the improvement of the soil biological properties. The aim of this study was to evaluate the soil microbial biomass, enzymes activity, and catabolic diversity under six different pastures: Andropogon gayanus, Brachiaria brizantha, Panicum maximum, Cynodon dactilon, agroforestry system, and native vegetation. Soil microbial biomass was estimated by the fumigation-extraction method, while enzyme activity was determined through substrate use. The catabolic diversity was evaluated by the community-level physiological profiling method. Microbial biomass C was higher in the soils under the agroforestry system and native vegetation, whereas microbial biomass N was higher in the soil under Brachiaria. Acid phosphatase activity and fluorescein diacetate hydrolysis were higher in agroforestry system and native vegetation, respectively. Dehydrogenase activity was higher in the soil under Brachiaria and Cynodon. Richness and diversity of community-level physiological profiling were higher in the soils under the agroforestry system and native vegetation. The highest numbers of C sources metabolized by microorganisms were found in the agroforestry system and native vegetation. This study showed that soil microbial community from pasture systems subjected to different management showed different biomass, activity, and catabolic diversity.

Teatime on Mount Kilimanjaro: Assessing climate and land‐use effects on litter decomposition and stabilization using the Tea Bag Index

“…Land-use intensification from seminatural SAV to MAI monocultures and from traditional HOM to large-scale COF decreased C stabilization and showed the tendency to increase decomposition rates ( Figure 6 and Figure 7). The total content of soil organic matter (SOM) and microbial biomass commonly decrease with land-use intensification (Don, Schumacher, & Freibauer, 2011;Junior et al, 2016).…”

Quantitative interactions between total and specific enzyme activities and C and N contents in earthworm‐affected pear orchard soil

“…The specific activities were obtained by dividing total enzyme activities by unit microbial biomass C (Waldrop, Balser, & Firestone, 2000). In the case of the soil respiration, total and specific activities are denoted as the basal respiration (BR) and metabolic quotient (qCO 2 ), respectively (Anderson & Domsch, 2010;Cardozo Junior et al, 2016).…”

“…Organic compound mineralization, during which C is released as CO 2 , enables the production of energy (adenosine triphosphate). Therefore, soil respiration data (CO 2 production) provide useful information on the intensity of oxidative energetic metabolism of soil heterotrophic populations and on the dynamics of soil organic matter mineralization (Cardozo Junior et al, 2016;Malý, Královec, & Hampel, 2009). Among intracellular enzymes, several dehydrogenases are considered to be especially important.…”

Halophyte residue decomposition and microbial community structure in coastal soil

“…Apart from the crucial role of soil microbial community structure (abundance of Gram-negative and Gram-positive bacterial, and fungal biomarkers), the decomposition of plant residues also depends on biochemical composition, that is, lignin contents and C/N ratio (Bray et al, 2012;Diedhiou et al, 2009;Franco-Andreu et al, 2017;Samahadthai, Vityakon, & Saenjan, 2010;Singh, 2016;Taylor & Middleton, 2004). However, most of the studies were carried out for agricultural crops and forestry plants due to their potential economic benefits linked with nutrient mineralization and their availability to subsequent crops rather than halophytes, which have potential economic and environmental benefits for coastal ecosystem (Hueso-González, Martínez-Murillo, & Ruiz-Sinoga, 2014;Junior et al, 2018;Qadir et al, 2008;Srivastava, Gupta, Shikha, Singh, & Tewari, 2016;Tejada & Benítez, 2014;Zhang et al, 2017), calls for continued investigations of the subject. To our knowledge, very few reports are available on impact of halophyte decomposition on microbial community on Indian saltmarshes, compared with other saltmarshes of the North America and Europe (Bouchard & Lefeuvre, 2000;Buth & de Wolf, 1985;Goodfriend et al, 1998;Menendez & Sanmarti, 2007;Simões et al, 2011).…”