scholarly journals Effect of Plant Growth Regulators on Protease Activity in Forest Floor of Norway Spruce Stand

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 665
Author(s):  
Ladislav Holik ◽  
Jiří Volánek ◽  
Valerie Vranová
Keyword(s):  
Organic Matter ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Forest Floor ◽  
Soil Microbial Activity ◽  
Inhibitory Effects ◽  
Chlorocholine Chloride ◽  
Soil Microbial ◽  
Native Soil ◽  
Transformation Processes

Soil proteases are involved in organic matter transformation processes and, thus, influence ecosystem nutrient turnovers. Phytohormones, similarly to proteases, are synthesized and secreted into soil by fungi and microorganisms, and regulate plant rhizosphere activity. The aim of this study was to determine the effect of auxins, cytokinins, ethephon, and chlorocholine chloride on spruce forest floor protease activity. It was concluded that the presence of auxins stimulated native proteolytic activity, specifically synthetic auxin 2-naphthoxyacetic acid (16% increase at added quantity of 5 μg) and naturally occurring indole-3-acetic acid (18%, 5 μg). On the contrary, cytokinins, ethephon and chlorocholine chloride inhibited native soil protease activity, where ethephon (36% decrease at 50 μg) and chlorocholine chloride (34%, 100 μg) showed the highest inhibitory effects. It was concluded that negative phytohormonal effects on native proteolytic activity may slow down organic matter decomposition rates and hence complicate plant nutrition. The study enhances the understanding of rhizosphere exudate effects on soil microbial activity and soil nitrogen cycle.

scholarly journals Alteration in the Native Proteolytic Activity in the Forest Soil after the Application of Phytohormones

2019 ◽  
Author(s):  
Ladislav Holik ◽  
Valerie Vranová
Keyword(s):  
Organic Matter ◽  
Proteolytic Activity ◽  
Inhibitory Effect ◽  
Tree Stand ◽  
Chlorocholine Chloride ◽  
Synthetic Auxins ◽  
Decomposition Of Organic Matter ◽  
Native Soil ◽  
Negative Effect ◽  
Transformation Of Organic Matter

Soil proteases are involved in the transformation of organic matter and thus influence the nutrient turnover in the ecosystem. Phytohormones, similarly to proteases, are synthesized and secreted into the soil by fungi and microorganisms and regulating their activity in the rhizosphere. The aim of our work was to find out how the presence of auxins, cytokinins, ethephone and chlorocholine chloride affects the activity of native soil proteases at the spruce tree stand. Auxins stimulated the native proteolytic activity in the spruce tree stand. Synthetic auxins most stimulated the activity of 2-naphthoxyacetic acid and the naturally occurring auxins of indole-3-acetic acid in the organic horizon of the spruce forest. Cytokinins, ethephone and chlorocholine chloride inhibited the activity of native soil proteases in the spruce tree stand. The highest inhibitory effect was found in ethephone and chlorocholine chloride. Overall, the negative effect of phytohormones on the activity of the native proteolytic activity may slow down the decomposition of organic matter and thus make plant nutrition more difficult. The outcomes of our work assist with understanding of the effect of substances produced by the rhizosphere on the activity of soil microorganisms and the soil nitrogen cycle.

Alterations in soil microbial activity and N-transformation processes due to sulfadiazine loads in pig-manure

2008 ◽  
Vol 153 (2) ◽  
pp. 315-322 ◽  
Author(s):  
Anja Kotzerke ◽  
Shilpi Sharma ◽  
Kristina Schauss ◽  
Holger Heuer ◽  
Sören Thiele-Bruhn ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Soil Microbial Activity ◽  
Pig Manure ◽  
Soil Microbial ◽  
N Transformation ◽  
Transformation Processes

scholarly journals The Relationship between Winter Temperature Rise and Soil Fertility properties

2012 ◽  
Vol 5 ◽  
pp. ASWR.S8599 ◽  
Author(s):  
Xiao Guoju ◽  
Zhang Qiang ◽  
Bi Jiangtao ◽  
Zhang Fengju ◽  
Luo Chengke
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Activity ◽  
Soil Ph ◽  
Salt Content ◽  
Soil Microbial Activity ◽  
Winter Temperature ◽  
Available Phosphorus ◽  
Available Nitrogen ◽  
Soil Microbial

The effects of winter temperature rises on soil microbial activity, nutrient and salinity in Ningxia Plain were studied in a field experiment using an infrared radiator to raise temperatures. Winter temperature rises led to increases in soil organic matter, available phosphorus, soil pH and total salt content, but decreased the available nitrogen in soil and the activities of soil catalase, urease and phosphatase. With a winter temperature of 0.5 °C-2.0 °C, the activities of soil catalase, urease and phosphatase were respectively decreased by 0.08-1.20 mL g-1, 0.004-0.019 mg g-1, and 0.10-0.25 mg kg-1; soil organic matter was increased by 0.01-0.62 g kg-1, available nitrogen decreased by 2.45-4.66 g kg-1, available phosphorus increased by 2.92-5.74 g kg-1; soil pH increased by 0.42-0.67, and total salt increased by 0.39-0.50 g kg-1. Winter temperature rises decreased soil microbial activity, accelerated the decomposition of soil nutrients, and intensified soil salinization.

scholarly journals Effects of long-term mowing on the fractions and chemical composition of soil organic matter in a semiarid grassland

2016 ◽  
Author(s):  
Jiang-Ye Li ◽  
Qi-Chun Zhang ◽  
Yong Li ◽  
Hong-Jie Di
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Soil Organic Matter ◽  
Functional Groups ◽  
Soil Microbial Activity ◽  
Net N Mineralization ◽  
Organic C ◽  
Semiarid Grassland ◽  
Soil Microbial ◽  
The Stability

Abstract. Grassland is the second largest carbon pool following forest. Intensive mowing is common to meet the need of increased livestock. However, little information on the quality and quantity of soil organic matter (SOM) under different mowing managements was documented. In this work, the fractions and chemical composition of SOM under different mowing managements were studied using traditional fractionation method and spectroscopy technology (13C-NMR and FTIR) based on a 13-year mowing trial with four treatments: control (CK, unmown), mowing once every second year (M1/2), mowing once a year (M1) and mowing twice a year (M2). The results showed that M1/2 and M1 significantly enhanced the SOM accumulation while M2 did not significantly impacted SOM content but it significantly limited the SOM humification and degradation. Substituted alkyl carbon (C) was the major organic C type as it made up over 40 % of the total C. M1/2 and M1 significantly increased stable C functional groups (alkyl C and aromatic C) by degrading labile C functional group (O-alkyl C) and forming calcium humic acid while M2 had opposite effects. The increase of NMR indices (HB/HI, Al/Ar, A/OA and CC/MC) in M1/2 and M1 further suggested that M1/2 and M1 increased the stability of SOM. Significant correlations between net N mineralization or MBC and C functional groups indicated that the shifts of SOM fractions and chemical composition were closely related to soil microbial activity. Meanwhile, M1 significantly increased soil MBC while M2 worked oppositely. Therefore, M1 are the most recommended mowing management while M2 should be avoided in the semiarid grassland.

scholarly journals Response of soil microbiota to nine-year application of swine manure and urea

2015 ◽  
Vol 46 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Diana Morales ◽  
Mónica Machado Vargas ◽  
Michele Pottes de Oliveira ◽  
Bruna Lunarde Taffe ◽  
Jucinei Comin ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Activity ◽  
Microbial Biomass Carbon ◽  
Soil Layer ◽  
Swine Manure ◽  
Soil Microbial Activity ◽  
Basal Respiration ◽  
Pig Slurry ◽  
Soil Microbial ◽  
Tillage System

ABSTRACT: Manure fertilization is a common practice, but little is known about its impacts on soil microbial activity and organic matter. Aiming to evaluate soil microbial response to nine years of successive applications of swine manure, organic carbon (TOC), total nitrogen (TN), pH, microbial biomass carbon (MBC), basal respiration (BR), metabolic quotient (qCO2), and enzyme (ß-glucosidase, phosphatase, arylsulphatase, and FDA) activities were measured in the 0-10cm soil layer, in a no-tillage system. Treatments were: control soil without fertilization (C), and application of two doses (104 and 209kg of N ha-1year-1) of urea (U1 and U2), pig slurry (PS1 and PS2) and deep litter (DL1 and DL2). TOC, TN, soil pH, MBC, and BR increased in soil fertilized with DL, and were lower in U treatments. Soils with U and DL application had higher qCO2, related to different sources of stressors like nutrient imbalance. Phosphatase and ß-glucosidase activities were not affected by treatments, increased with time, and had a strong correlation with MBC. We conclude that long-term swine manure applications increase microbial activity and soil organic matter, mainly in DL form; while urea applications have negative impacts on these indicators.

scholarly journals Plant genotype controls wetland soil microbial functioning in response to sea-level rise 

2021 ◽  
Author(s):  
Hao Tang ◽  
Susanne Liebner ◽  
Svenja Reents ◽  
Stefanie Nolte ◽  
Kai Jensen ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Soil Microbial Communities ◽  
Soil Microbial Activity ◽  
Litter Breakdown ◽  
Plant Genotype ◽  
Soil Microbial

Abstract. Climate change induced shifts in plant community composition affect the decomposition of soil organic matter via plant-microbe interactions, often with important consequences for ecosystem carbon and nutrient cycling. Given the high degree of intraspecific trait variability in plants, it has been hypothesized that genetic shifts within species yield a similar potential to affect soil microbial functioning.We examined if sea-level rise and plant genotype interact to affect soil microbial communities in an experimental coastal wetland system, using two known genotypes of the dominant salt-marsh grass Elymus athericus characterized by differences in their sensitivity to flooding stress – i.e. an adapted genotype from low-marsh environments and an unadapted genotype from high-marsh environments. Plants were exposed to a large range of flooding frequencies in a factorial mesocosm experiment, and soil microbial-activity parameters (exo-enzyme activity and litter breakdown) and microbial community structure were assessed.Plant genotype mediated the effect of flooding on soil microbial community structure and determined the presence of flooding effects on exo-enzyme activities and belowground litter breakdown. Larger variability in microbial community structure, enzyme activities, and litter breakdown in soils planted with the unadapted plant genotype supported our general hypothesis that effects of climate change on soil microbial activity and community structure can depend on plant intraspecific adaptations. We conclude that adaptive genetic variation in plants can suppress or facilitate the effects of climate change on soil microbial communities. If this finding applies more generally to wetland ecosystems and beyond, it yields important implications for experimental climate change research and models of soil organic matter accumulation.

Life in Dry Soils: Effects of Drought on Soil Microbial Communities and Processes

2018 ◽  
Vol 49 (1) ◽  
pp. 409-432 ◽  
Author(s):  
Joshua P. Schimel
Keyword(s):  
Organic Matter ◽  
Hydrological Cycle ◽  
Soil Microbial Communities ◽  
Terrestrial Ecosystems ◽  
Soil Microbial Activity ◽  
Soil Processes ◽  
Microbial Life ◽  
Soil Microbial ◽  
Effects Of Drought ◽  
Main Effects

Throughout Earth's history, drought has been a common crisis in terrestrial ecosystems; in human societies, it can cause famine, one of the Four Horsemen of the apocalypse. As the global hydrological cycle intensifies with global warming, deeper droughts and rewetting will alter, and possibly transform, ecosystems. Soil communities, however, seem more tolerant than plants or animals are to water stress—the main effects, in fact, on soil processes appear to be limited diffusion and the limited supply of resources to soil organisms. Thus, the rains that end a drought not only release soil microbes from stress but also create a resource pulse that fuels soil microbial activity. It remains unclear whether the effects of drought on soil processes result from drying or rewetting. It is also unclear whether the flush of activity on rewetting is driven by microbial growth or by the physical/chemical processes that mobilize organic matter. In this review, I discuss how soil water, and the lack of it, regulates microbial life and biogeochemical processes. I first focus on organismal-level responses and then consider how these influence whole-soil organic matter dynamics. A final focus is on how to incorporate these effects into Earth System models that can effectively capture dry–wet cycling.

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