scholarly journals CHANGES IN C : N : Р RATIOS IN PLANT BIOMASS, SOIL AND SOIL MICROBIAL BIOMASS DUE TO THE WARMING AND DESSICATION EFFECT OF FLARING

2018 ◽  
pp. 71-89 ◽  
Author(s):  
D. M. Dudareva ◽  
A. K. Kvitkina ◽  
I. A. Yusupov ◽  
I. V. Yevdokimov
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Plant Biomass ◽  
Abiotic Factors ◽  
Methodological Approach ◽  
Terrestrial Ecosystems ◽  
Water Soluble ◽  
Oil Well ◽  
Soil Microbial ◽  
Stoichiometric Ratios

Climate warming results in significant changes in the structure and functioning of terrestrial ecosystems. The ecosystems situated near oil-well gas flares may be used as model ones for studying warming effect on soil and vegetation. By contrast to regular manipulation experiments where ecopysiological factors are modified or controlled artificially, we used anthropogenically affected condi-tions caused by the gas flaring. Our research was aimed to assess the warming and desiccation effect on the stoichiometric ratios of the principle nutrients (C : N : P) in pine phytomass, soil and soil microbial biomass. Soil organic matter (SOM) and dying microbial biomass were found to be exposed to the increased rate of mineralization under conditions of the abiotic stress. In addition, the de-crease of relative С content in sustainable SOM pools occured along with the increase of C content in the most labile water-soluble pools. Accelerated SOM mineralization decreasing C : N with respect to phosphorus ratio in soil and soil microbial biomass was sufficiently intensified by the decrease in C : N : P in pine needles. Thus, studying changes in stoichiometric ratios of biophylic ele-ments as affected by abiotic factors seems to be prospective and promising methodological approach for predicting terrestrial ecosystem transformations under global climate changes.

Nitrogen mineralisation rates from soil amended with dairy pond waste

Soil Research ◽  
1998 ◽  
Vol 36 (2) ◽  
pp. 217 ◽  
Author(s):  
M. J. Noonan ◽  
M. Zaman ◽  
K. C. Cameron ◽  
H. J. Di
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Water Soluble ◽  
Organic N ◽  
Ammonium Concentration ◽  
Soil Leachate ◽  
Soil Microbial ◽  
N Release ◽  
Soluble C ◽  
Water Soluble C

An open incubation and leaching study was conducted under controlled temperature (25°C) and moisture conditions to measure the N mineralisation rate in soil amended with dairy pond sludge. The dairy pond sludge was applied at 3 different rates equivalent to 0, 200, and 400 kg N/ha. The incubation was conducted at 3 different soil moisture potentials (0, -3, and -13 kPa). Following each 2-week period of incubation, the soil was leached with 2 pore volumes of deionised water to remove the mineralisation products. Mineralisation products in the leachate and enzyme activities, microbial biomass C and N, pH, and water-soluble C in the soil were determined. The incubation lasted 18 weeks. Rapid release of nitrate occurred during the first 6 weeks of incubation, followed by a slow release over the remainder of the incubation period. Although the total amount of N released in the 200 kg N/ha treatment (169 mg N/kg soil) was less than in the 400 kg N/ha treatment (206 mg N/kg soil), when expressed as a percentage of the organic N applied, the amount of N released at the lower rate (18·4%) was greater than that at the higher rate of sludge treatment (13·0%). Rapid nitrification decreased the soil leachate ammonium concentration and the soil pH. Soil microbial biomass, water-soluble C, and deaminase activity were significantly increased after the addition of dairy pond sludge. The increase in soil microbial biomass observed was probably due to the increased water-soluble C and nutrients that stimulated the soil microbial growth. The rapid N release and nitrification rates observed were attributed to the low C : N ratio (12·7), high ammonium content (145 mg N/kg) of the dairy pond sludge used, and the optimum moisture and temperature conditions. The narrow range of soil water potential conditions did not have any significant effect on N release rate or amount.

scholarly journals Plant Biomass and Soil Nutrients Mainly Explain the Variation of Soil Microbial Communities during Secondary Succession on the Loess Plateau

2021 ◽  
Author(s):  
Miao-Ping Xu ◽  
Jia-Yi Wang ◽  
Xin-Hui Han ◽  
Cheng-Jie Ren ◽  
Gai-He Yang
Keyword(s):  
Microbial Biomass ◽  
Soil Nutrients ◽  
Soil Microbial Biomass ◽  
Plant Biomass ◽  
Soil Microbial Communities ◽  
Fungal Communities ◽  
The Loess Plateau ◽  
Soil Microbial ◽  
Plant Characteristics ◽  
Soil Bacterial

Abstract Soil microorganisms play an important role in the circulation of materials and nutrients between plants and soil ecosystems, but the drivers of microbial community composition and diversity remain uncertain in different vegetation restoration patterns. We studied soil physicochemical properties (i.e., soil moisture, bulk density, pH, soil nutrients, available nutrients), plant characteristics (i.e., Shannon index [HPlant] and Richness index [SPlant], litter biomass [LB], and fine root biomass [FRB]), and microbial variables (biomass, enzyme activity, diversity and composition of bacterial and fungal communities) in different plant succession patterns (Robinia pseudoacacia [MF], Caragana korshinskii [SF] and grassland [GL]) on the Loess Plateau. The herb communities, soil microbial biomass and enzyme activities were strongly affected by vegetation restoration. And soil bacterial and fungal communities were significantly different from each other at the sites. Furthermore, LB and FRB were significantly positively correlated with SBacteria, soil microbial biomass, enzyme activities, Proteobacteria, Zygomycota and Cercozoa, while negatively correlated with Actinobacteria and Basidiomycota. In addition, soil water content (SW), pH and nutrients have important effects on the bacterial and fungal diversities, Acidobacteria, Proteobacteria, Nitrospirae, Zygomycota and microbial biomass. Furthermore, plant characteristics and soil properties modulated the composition and diversity of soil microorganisms, respectively. Overall, the relative contribution of vegetation and soil to the diversity and composition of soil bacterial and fungal communities illustrated that plant characteristics and soil properties may synergistically modulate soil microbial communities. And soil bacterial and fungal communities mainly depend on plant biomass and soil nutrients.

scholarly journals Stoichiometric characteristics of microbial biomass in oil-contaminated soil in the loess hilly region

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Lei Shi ◽  
Zhongzheng Liu
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Contaminated Soil ◽  
Soil Microbial Biomass ◽  
Oil Pollution ◽  
Soil Samples ◽  
Oil Well ◽  
Soil Microbial ◽  
Petroleum Contaminated Soil ◽  
Petroleum Pollutants

Abstract Purpose The present study envisaged the stoichiometry of microbial biomass in petroleum-contaminated soil, in order to study the influence of the petroleum-contaminated soil on the ecosystem stability. Methods A typical oil well area in the Northern Shaanxi was considered the research object and the oil pollution status was assessed by studying the physical, chemical, and microbiological characteristics of the soil in the area. Results From the measurement and analysis of the petroleum pollutants in the soil samples, it was observed that the concentration of the petroleum pollutants around all the oil well areas was higher than the critical value of 500 mg/kg. Furthermore, the C to N ratio of 8 soil samples around the oil wells (0.8:1~13.3:1) was lower than that of the control soil samples in most cases and could not reach the nutrient proportion level required by soil microorganisms. It was observed that the oil organic carbon content at 0~10 m from the wellhead was obviously higher than that in other areas, and decreased with an increase in the distance from the well. Based on the determination of soil organic carbon, total nitrogen, total phosphorus, and the soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and phosphorus content analysis, it was observed that only the soil organic carbon was significantly positively correlated to the oil pollutants in soil. Conclusions Imbalance in the C to N, SMBC, and SMBN ratio can lead to an acute shortage of the required nutrients than microorganisms, limit the soil microbial reproduction and growth, and thereby slow down the rate of indigenous microbial degradation of petroleum hydrocarbons, so as to reduce the impact of oil pollution on the stability of the entire ecosystem. Therefore, during the remediation of petroleum-contaminated soil in this study area, adequate nutrients need to be reasonably added to the soil.

scholarly journals Co-evolution hints at soil microbial biomass as the entity of soil fertility

2015 ◽  
Author(s):  
Masato Oda ◽  
Yasukazu Hosen ◽  
Uchada Sukchan
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Soil Properties ◽  
Crop Yield ◽  
Soil Microbial Biomass ◽  
Crop Yields ◽  
Plant Biomass ◽  
Total N ◽  
Soil Microbial ◽  
Wide Range

Nitrogen (N) and Carbon (C) are popular indicators of soil fertility; however, they are not soil fertility itself. In fact, they may be seen as just two aspects of the one entity. Soil microbial biomass (SMB) is also one of soil fertility indicators; furthermore, recent study of co-evolution between plants and microorganisms raises an idea that SMB might be the entity of fertility. The correlation between SMB and crop yield has been found in some studies but not in others. Those studies were conducted from the standpoint of N stock balance; therefore, the correlation between soil properties before planting and plant yields were analyzed. Here, we show—in our analysis of harvest-time soil properties and crop yields—that SMB correlates more strongly than inorganic N, total N, or total C with average crop yield under a wide range of cultivation conditions. From the viewpoint of co-evolution, plant biomass is a part of the plant and soil microorganism system; therefore, increasing SMB will balance by increasing plant biomass. In addition, the SMB could increase independently from the plant growth by artificial organic matter input. This concept will break through the yield limitation of conventional farming.

scholarly journals Co-evolution hints at soil microbial biomass as the entity of soil fertility

2015 ◽  
Author(s):  
Masato Oda ◽  
Yasukazu Hosen ◽  
Uchada Sukchan
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Soil Properties ◽  
Crop Yield ◽  
Soil Microbial Biomass ◽  
Crop Yields ◽  
Plant Biomass ◽  
Total N ◽  
Soil Microbial ◽  
Wide Range

Nitrogen (N) and Carbon (C) are popular indicators of soil fertility; however, they are not soil fertility itself. In fact, they may be seen as just two aspects of the one entity. Soil microbial biomass (SMB) is also one of soil fertility indicators; furthermore, recent study of co-evolution between plants and microorganisms raises an idea that SMB might be the entity of fertility. The correlation between SMB and crop yield has been found in some studies but not in others. Those studies were conducted from the standpoint of N stock balance; therefore, the correlation between soil properties before planting and plant yields were analyzed. Here, we show—in our analysis of harvest-time soil properties and crop yields—that SMB correlates more strongly than inorganic N, total N, or total C with average crop yield under a wide range of cultivation conditions. From the viewpoint of co-evolution, plant biomass is a part of the plant and soil microorganism system; therefore, increasing SMB will balance by increasing plant biomass. In addition, the SMB could increase independently from the plant growth by artificial organic matter input. This concept will break through the yield limitation of conventional farming.

scholarly journals Plant mixture balances terrestrial ecosystem C:N:P stoichiometry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xinli Chen ◽  
Han Y. H. Chen
Keyword(s):  
Microbial Biomass ◽  
Plant Diversity ◽  
Soil Microbial Biomass ◽  
Meta Analysis ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
C:N:P Stoichiometry ◽  
Soil Microbial ◽  
Species Mixture ◽  
Background Soil

AbstractPlant and soil C:N:P ratios are of critical importance to productivity, food-web dynamics, and nutrient cycling in terrestrial ecosystems worldwide. Plant diversity continues to decline globally; however, its influence on terrestrial C:N:P ratios remains uncertain. By conducting a global meta-analysis of 2049 paired observations in plant species mixtures and monocultures from 169 sites, we show that, on average across all observations, the C:N:P ratios of plants, soils, soil microbial biomass and enzymes did not respond to species mixture nor to the species richness in mixtures. However, the mixture effect on soil microbial biomass C:N changed from positive to negative, and those on soil enzyme C:N and C:P shifted from negative to positive with increasing functional diversity in mixtures. Importantly, species mixture increased the C:N, C:P, N:P ratios of plants and soils when background soil C:N, C:P, and N:P were low, but decreased them when the respective background ratios were high. Our results demonstrate that plant mixtures can balance terrestrial plant and soil C:N:P ratios dependent on background soil C:N:P. Our findings highlight that plant diversity conservation does not only increase plant productivity, but also optimizes ecosystem stoichiometry for the diversity and productivity of today’s and future vegetation.

scholarly journals Precipitation Changes Regulate Plant and Soil Microbial Biomass Via Plasticity in Plant Biomass Allocation in Grasslands: A Meta-Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Chunhui Zhang ◽  
Nianxun Xi
Keyword(s):  
Microbial Biomass ◽  
Biomass Allocation ◽  
Soil Microbial Biomass ◽  
Plant Biomass ◽  
Microbial Biomass C ◽  
Soil Microbial ◽  
Microbial Responses ◽  
Precipitation Changes ◽  
Precipitation Reduction ◽  
Belowground Plant Biomass

In theory, changes in the amount of rainfall can change plant biomass allocation and subsequently influence coupled plant-soil microbial processes. However, testing patterns of combined responses of plants and soils remains a knowledge gap for terrestrial ecosystems. We carried out a comprehensive review of the available literature and conducted a meta-analysis to explore combined plant and soil microbial responses in grasslands exposed to experimental precipitation changes. We measured the effects of experimental precipitation changes on plant biomass, biomass allocation, and soil microbial biomass and tested for trade-offs between plant and soil responses to altered precipitation. We found that aboveground and belowground plant biomass responded asynchronically to precipitation changes, thereby leading to shifts in plant biomass allocation. Belowground plant biomass did not change under precipitation changes, but aboveground plant biomass decreased in precipitation reduction and increased in precipitation addition. There was a trade-off between responses of aboveground plant biomass and belowground plant biomass to precipitation reduction, but correlation wasn't found for precipitation addition. Microbial biomass carbon (C) did not change under the treatments of precipitation reduction. Increased root allocation may buffer drought stress for soil microbes through root exudations and neutralize microbial responses to precipitation reduction. However, precipitation addition increased microbial biomass C, potentially reflecting the removal of water limitation for soil microbial growth. We found that there were positive correlations between responses of aboveground plant biomass and microbial biomass C to precipitation addition, indicating that increased shoot growth probably promoted microbial responses via litter inputs. In sum, our study suggested that aboveground, belowground plant biomass and soil microbial biomass can respond asynchronically to precipitation changes, and emphasizes that testing the plant-soil system as a whole is necessary for forecasting the effects of precipitation changes on grassland systems.

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