scholarly journals Parent material and organic matter control soil microbial processes in African tropical rainforests 

2021 ◽  
Author(s):  
Laurent Kidinda Kidinda ◽  
Folasade Kemi Ologoke ◽  
Cordula Vogel ◽  
Karsten Kalbitz ◽  
Sebastian Doetterl
Keyword(s):  
Microbial Biomass ◽  
Tropical Rainforest ◽  
Parent Material ◽  
Microbial Processes ◽  
Tropical Rainforests ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil Microbial ◽  
Microbial C ◽  
C Limitation

<p>Microbial processes are one of the key factors driving carbon (C) and nutrient cycling in terrestrial ecosystems, and are strongly controlled by the equilibrium between resource availability and demand. In deeply weathered tropical rainforest soils of Africa, it remains unclear whether patterns of microbial processes differ between soils developed from geochemically contrasting parent material. Here, we investigate patterns of soil microbial processes and their controls in tropical rainforests of Africa. We used soil developed from three geochemically distinct parent material (mafic, felsic, mixed sedimentary rocks) and three soil depths (0−70 cm). We measured microbial biomass C and enzyme activity at the beginning and end of a 120-day incubation experiment. We also conducted a vector analysis based on ecoenzymatic stoichiometry to assess microbial C and nutrient limitations. We found that microbial C limitation was highest in the mixed sedimentary region and lowest in the felsic region, which we propose was related to the strength of contrasting C stabilization mechanisms and varying C quality. None of the investigated regions and soil depths showed signs of nitrogen (N) limitation for microbial processes. Microbial phosphorus (P) limitation increased with soil depth, indicating that subsoils in the investigated soils were depleted in rock-derived nutrients and are therefore dependent on efficient nutrient recycling. Microbial C limitation was lowest in subsoils, indicating that subsoil microbes cannot significantly participate in C cycling and limit C storage if oxygen is not available, but can do so in our laboratory incubation experiment under well aerated conditions. Using multivariable regressions, we demonstrate that microbial biomass C normalized to soil organic C content (MBC<sub>SOC</sub>) is controlled by soil geochemistry and substrate quality, while microbial biomass C normalized to soil weight (MBC<sub>Soil</sub>) is predominantly driven by resource distribution (i.e., depth distribution of organic C). We conclude that due to differences in resource availability, microbial processes in deeply weathered tropical rainforest soils greatly vary across geochemical regions.</p>

scholarly journals Patterns of microbial processes shaped by parent material and soil depth in tropical rainforest soils

2020 ◽  
Author(s):  
Laurent K. Kidinda ◽  
Folasade K. Olagoke ◽  
Cordula Vogel ◽  
Karsten Kalbitz ◽  
Sebastian Doetterl
Keyword(s):  
Microbial Biomass ◽  
Resource Availability ◽  
Tropical Rainforest ◽  
Soil Depth ◽  
Microbial Processes ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil Microbial ◽  
Microbial C ◽  
C Limitation

Abstract. Microbial processes are one of the key factors driving carbon (C) and nutrient cycling in terrestrial ecosystems, and are strongly driven by the equilibrium between resource availability and demand. In deeply weathered tropical rainforest soils of Africa, it remains unclear whether patterns of microbial processes differ between soils developed from geochemically contrasting parent materials. Here we show that resource availability across soil depths and regions from mafic to felsic geochemistry shape patterns of soil microbial processes. During a 120-day incubation experiment, we found that microbial biomass C and extracellular enzyme activity were highest in the mafic region. Microbial C limitation was highest in the mixed sedimentary region and lowest in the felsic region, which we propose is related to the strength of contrasting C stabilization mechanisms and varying C quality. None of the investigated regions and soil depths showed signs of nitrogen (N) limitation for microbial processes. Microbial phosphorus (P) limitation increased with soil depth but was similar across geochemical regions, indicating that subsoils in the investigated soils were depleted in rock-derived nutrients and are therefore dependent on efficient biological recycling of nutrients. Microbial C limitation was lowest in subsoils, indicating that subsoil microbes can significantly participate in C cycling and limit C storage if increased oxygen availability is prevalent. Using multivariable regressions, we demonstrate that microbial biomass C normalized to soil organic C content (MBCSOC) is controlled by soil geochemistry and substrate quality, while microbial biomass C normalized to soil weight (MBCSoil) is predominantly driven by resource distribution. We conclude that due to differences in resource availability, microbial processes in deeply weathered tropical rainforest soils greatly vary across geochemical regions which must be considered when assessing soil microbial processes in organic matter turnover models.

Dynamics of soil microbial biomass C, soluble organic C and CO2 evolution after three years of manure application

1998 ◽  
Vol 78 (2) ◽  
pp. 283-290 ◽  
Author(s):  
P. Rochette ◽  
E. G. Gregorich
Keyword(s):  
Microbial Biomass ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Soil Microbial Biomass ◽  
N Fertilizer ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil Microbial ◽  
Manure Amendments ◽  
Soluble C

Application of manure and fertilizer affects the rate and extent of mineralization and sequestration of C in soil. The objective of this study was to determine the effects of 3 yr of application of N fertilizer and different manure amendments on CO2 evolution and the dynamics of soil microbial biomass and soluble C in the field. Soil respiration, soluble organic C and microbial biomass C were measured at intervals over the growing season in maize soils amended with stockpiled or rotted manure, N fertilizer (200 kg N ha−1) and with no amendments (control). Manure amendments increased soil respiration and levels of soluble organic C and microbial biomass C by a factor of 2 to 3 compared with the control, whereas the N fertilizer had little effect on any parameter. Soil temperature explained most of the variations in CO2 flux (78 to 95%) in each treatment, but data from all treatments could not be fitted to a unique relationship. Increases in CO2 emission and soluble C resulting from manure amendments were strongly correlated (r2 = 0.75) with soil temperature. This observation confirms that soluble C is an active C pool affected by biological activity. The positive correlation between soluble organic C and soil temperature also suggests that production of soluble C increases more than mineralization of soluble C as temperature increases. The total manure-derived CO2-C was equivalent to 52% of the applied stockpiled-manure C and 67% of the applied rotted-manure C. Estimates of average turnover rates of microbial biomass ranged between 0.72 and 1.22 yr−1 and were lowest in manured soils. Manured soils also had large quantities of soluble C with a slower turnover rate than that in either fertilized or unamended soils. Key words: Soil respiration, greenhouse gas, soil carbon

Short-term effects on soil of biogas digestate, biochar and their combinations

Soil Research ◽  
2018 ◽  
Vol 56 (6) ◽  
pp. 623 ◽  
Author(s):  
Roberto Cardelli ◽  
Gabriele Giussani ◽  
Fausto Marchini ◽  
Alessandro Saviozzi
Keyword(s):  
Microbial Biomass ◽  
Antioxidant Capacity ◽  
Biogas Production ◽  
Co2 Production ◽  
Microbial Biomass C ◽  
Negative Effects ◽  
Short Term ◽  
Organic C ◽  
Soil C ◽  
Soil Microbial

The use of the residual material from waste aerobic digestion and biochar as amendments is currently discussed in the literature concerning the positive and negative effects on soil quality. We assessed the suitability of digestate (D) from biogas production and green biochar (B) to improve soil biological activity and antioxidant capacity and investigated whether there is an interaction between digestate and biochar applied to soil in combination. In a short-term (100-days) laboratory incubation, we monitored soil chemical and biological parameters. We compared soil amendments with 1% D (D1), 5% D (D5), 1% B (B), digestate–biochar combinations (D1+B and D5+B), and soil with no amendment. In D5, CO2 production, antioxidant capacity (TEAC), and dehydrogenase activity (DH-ase) and the contents of microbial biomass C, DOC and alkali-soluble phenols increased to the highest level. The biochar increased the total organic C (TOC) and TEAC of soil but decreased DOC, CO2 production, microbial biomass C, and DH-ase. The addition of biochar to digestate reduced soluble compounds (DOC and phenols), thus limiting the amount and activity of the soil microbial biomass (CO2 production and DH-ase). After 100 days of incubation D5+B showed the highest TOC content (82.8% of the initial amount). Both applied alone and in combination with digestate, the biochar appears to enrich the soil C sink by reducing CO2 emissions into the atmosphere.

Soil microbial biomass, labile and total carbon levels of grazed sown and native pastures in northern New South Wales

2006 ◽  
Vol 57 (8) ◽  
pp. 837 ◽  
Author(s):  
G. M. Lodge ◽  
K. L. King
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Perennial Grass ◽  
Ground Cover ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil Microbial ◽  
Labile C ◽  
Microbial Quotient ◽  
Total Organic C

Studies were conducted at 3 pasture sites in northern New South Wales to examine the effects of grazing treatments over 4 years (spring 1997 to spring 2001) on soil microbial biomass carbon (C), labile C, total C, and total nitrogen (N). These data were collected (0–0.05 m soil depth) at 9 sampling times in 2 replicates of 5 (native pastures) or 4 (a sown pasture) grazing treatments and examined for differences over time using cubic spline analyses. For each site, differences among grazing treatments were also examined in spring 2001 for herbage, litter, and root mass (kg DM/ha), ground cover (%), and perennial grass basal cover (%). Indices were also calculated for the C pool index (CPI), lability index (LI), a carbon management index (CMI), and the microbial quotient. Relationships among microbial biomass C, labile C, total organic C, CPI, LI, CMI, microbial quotient, herbage mass, litter mass, and ground cover were examined by linear regression and correlation analyses. For each of the sites, treatment differences in the linear trend over time for soil microbial biomass C, labile C, total organic C, or total N were not significantly different (P > 0.05). In spring 2001, (4 years after treatments commenced) there were also no significant effects of treatments within sites on soil total organic C and none of the indices (lability of C, CPI, LI, CMI, or the microbial quotient) indicated any distinct trends among treatments. However, in spring 2001, there were significant (P < 0.05) treatment effects at both native pasture sites for herbage mass, litter mass, and ground cover. Similarly, in autumn 2001, herbage mass, root mass, and perennial grass basal cover were lowest (P < 0.05) in the continuously grazed high-stocking rate treatment at the sown pasture site. For all data, microbial biomass C was 10.35% of labile C and labile C was 21.60% of total C. From autumn 1998 to spring 2001, labile C was positively correlated (P < 0.05) with total C (r = 0.72) and in spring 2001, these 2 variables were also highly correlated (r = 0.98).

ALLOCATION AND MICROBIAL UTILIZATION OF C IN TWO SOILS CROPPED TO BARLEY

1988 ◽  
Vol 68 (3) ◽  
pp. 495-505 ◽  
Author(s):  
G. D. DINWOODIE ◽  
N. G. JUMA
Keyword(s):  
Microbial Biomass ◽  
Black Soil ◽  
Water Soluble ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil C ◽  
Microbial Utilization ◽  
Below Ground ◽  
Microbial C ◽  
Soluble C

This study was undertaken to compare some aspects of carbon cycling in a Gray Luvisol at Breton and a Black soil at Ellerslie, Alberta cropped to barley. Comparisons of the above and below-ground allocation of carbon, distribution of carbon in soil, and microbial use of carbon were made between sites. Shoot C, root C, microbial biomass C, soil organic C, water soluble organic C, and polysaccharide C were measured on four dates between 31 July and 20 Oct. 1986. The total quantity of carbon in the soil-plant system at Ellerslie (17.2 kg C m−2) was greater than at Breton (6.6 kg C m−2). On average shoot C at Ellerslie (247 g C m−2) was greater than at Breton (147 g m−2). The quantity of root C (avg. 21 g C m−2) was the same at both sites resulting in higher shoot C:root C ratios at Ellerslie than Breton. Microbial biomass (expressed as g C m−2 or g C g−1 root C) was one to two times lower at Breton than at Ellerslie but respiration (g CO2-C g−1 microbial biomass C) during a 10-d laboratory incubation was two to four times greater. Microbial biomass C, soluble C and polysaccharide C expressed as mg C g−1 of soil were less at Breton than Ellerslie. However when these data were compared on a relative basis in terms of soil C (g C g−1 soil C), microbial biomass C and soluble C were higher at Breton than Ellerslie. Polysaccharide C was the same at both sites. Although the microbial biomass was smaller at Breton than at Ellerslie, more carbon was lost from the system by microbial respiration and a greater proportion of the carbon in the soil was in microbial and soluble C pools. Soil characteristics, and cropping history affected the amount of carbon stabilized in soil. Key words: Chernozemic, Luvisolic, microbial C, soluble C, polysaccharide C, soil organic matter, barley

Microbial activity and survival in soils dried at different rates

Soil Research ◽  
1992 ◽  
Vol 30 (2) ◽  
pp. 209 ◽  
Author(s):  
AW West ◽  
GP Sparling ◽  
CW Feltham ◽  
J Reynolds
Keyword(s):  
Microbial Biomass ◽  
Water Content ◽  
Microbial Activity ◽  
Initial Period ◽  
Organic Matter Content ◽  
Matter Content ◽  
Survival Strategies ◽  
Microbial Biomass C ◽  
Organic C ◽  
Microbial C

The changes in microbial biomass C, soil respiration, microbial activity (respiration/microbial C) and the content of oxidizable organic C extracted by 0-5 M K2SO4, were measured in four soils of contrasting characteristics (a sand, two silt loam soils and a peat) which were air-dried at 22�C at three different rates in the laboratory. Respiration was also measured on samples of the drying soils rewetted with water. The rates of drying were: <10 h (fast), <33 h (medium) and <62 h (slow); drying was carried out for 6 h on consecutive days, with overnight storage. Measurements were also made on soils stored at field-moisture content over the 15 day duration of the experiment. Respiration and activity declined continuously and in a generally linear manner as the volumetric water content (W,) decreased. The decline in respiration in relation to water content W, was similar for all four soils and for the three rates of drying. Microbial biomass C also declined but generally only after a considerable initial period of drying (after the soils had reached Wv of 0-1-0.3). Extractable C values increased, but only after an initial drying period (Wv below 0.06-0.12). The increases in extractable C were approximately coincident with the decreases in microbial C, but only part of the increase in extractable C could be accounted for by the decrease in microbial C. Rewetting of dried soils caused a marked increase in respiration, particularly when the rewetted soils had reached Wv values where extractable C had begun to increase. The relationship between microbial activity and extractable C was similar for all four soils and was not affected by the rate of drying. The similarity of the microbial responses in these contrasting soils, and the absence of any detectable differences between rates of drying suggest that the microbial communities had similar survival strategies to resist desiccation, and occupied comparable physical niches in the soils, despite these soils having widely differing textures, organic matter content, and soil moisture characteristics.

scholarly journals Relative contribution of plant traits and soil properties to the functioning of a temperate forest ecosystem in the Indian Himalayas

2019 ◽  
Author(s):  
Monika Rawat ◽  
Kusum Arunachalam ◽  
Ayyandar Arunachalam ◽  
Juha Alatalo ◽  
Ujjwal Kumar ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Properties ◽  
Temperate Forest ◽  
Soil Microbial Biomass ◽  
Plant Traits ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil Microbial Biomass C ◽  
Soil Microbial ◽  
Leaf N

Plant-soil interactions are a major determinant of changes in forest ecosystem processes and functioning. We conducted a trait-based study to quantify the contribution of plant traits and soil properties to above- and below-ground ecosystem properties in temperate forest in the Indian Himalayas. Nine plant traits (leaf area, specific leaf area, leaf water content, leaf dry matter content, leaf carbon (C), nitrogen (N), phosphorus (P), leaf C/N, and leaf N/P) and eight soil properties (pH, moisture, available N, P, potassium (K), total C, N, P) were selected for determination of their contribution to major ecosystem processes (above-ground biomass C, soil organic C, soil microbial biomass C, N, and P, and soil respiration) in temperate forest. Among the plant traits studied, leaf C, N, P, and leaf N/P ratio proved to be the main contributors to above-ground biomass, explaining 20-27% of variation. Leaf N, P, and leaf N/P were the main contributors to below-ground soil organic C, soil microbial biomass C, N, and P, and soil respiration (explaining 33% of variation). Together, the soil properties pH, available P, total N and C explained 60% of variation in above-ground biomass, while pH and total C explained 56% of variation in soil organic C. Other soil properties (available P, total C and N) also explained much of the variation in soil microbial biomass C (52%) and N (67%), while soil pH explained some of variation in soil microbial biomass N (14%). Available P, total N, and pH explained soil microbial biomass P (81%), while soil respiration was only explained by soil total C (70%). Thusleaf traits and soil characteristics make a significant contribution to explaining variations in above- and below-ground ecosystem processes and functioning in temperate forest in the Indian Himalayas. Consequently, tree species for afforestation, restoration, and commercial forestryshould be carefully selected, as they can influence the climate change mitigation potential of forest in terms of C stocks in biomass and soils.

Recovery of soil microbial biomass and activity from prescribed burning

1993 ◽  
Vol 23 (7) ◽  
pp. 1286-1290 ◽  
Author(s):  
Hannu Fritze ◽  
Taina Pennanen ◽  
Janna Pietikäinen
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Prescribed Burning ◽  
Coniferous Forest ◽  
Plant Succession ◽  
Microbial Biomass C ◽  
Respiration Activity ◽  
Organic C ◽  
Soil Microbial ◽  
Humus Layer

Development of humus layer soil microbial biomass C (Cmic) and N (Nmic), fungal biomass (as soil ergosterol content), microbial respiration activity, and the soil organic C (Corg) and N (Ntot) were determined in coniferous forest soils that had received a single prescribed fire treatment at different times over a period of 45 years. The ratio of soil respiration rate to microbial biomass C (qCO2) and the Cmic/Corg and Nmic/Ntot percentages were derived from the measurements taken. All the measured biomass indicators reacted identically to show recovery from prescribed burning within 12 years. A raised metabolic quotient (qCO2) was detected in soils over the first 2 years following the fire treatment, but after the third year it had decreased to a stable level. These observations suggest that during the first few years after fire the soil microflora can be characterized on the basis of simple substrate–decomposer relationships. The first 12 years were characterized by increasing Cmic/Corg and Nmic/Ntot percentages, which then stabilized at mean values of 1.3 and 5.5%, respectively. The observed rise in the Cmic within a large pool of Corg suggested increasing availability of energy-rich C sources. These C sources are probably derived from the organic C input resulting from postfire plant succession.

scholarly journals Evolution of Physico-Chemical Properties, Microbial Biomass and Microbial Activity of an Urban Soil after De-Sealing

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 596
Author(s):  
Giancarlo Renella
Keyword(s):  
Microbial Biomass ◽  
Urban Soil ◽  
Urban Soils ◽  
Soil Microbial Biomass ◽  
Microbial Biomass C ◽  
Microbial Biomass N ◽  
Inorganic N ◽  
Organic C ◽  
Soil Microbial ◽  
Physico Chemical

Recovery of soil fertility after de-sealing of urban soils is still poorly known. This work studied the time-related dynamics of soil physico-chemical and biochemical endpoints of urban soil in the city in Naples (Southern Italy), de-sealed for different time during construction works, that underwent colonization by volunteer plants. The results showed de-sealing decreased the soil bulk density and the soil pH value, increased the electrical conductivity (EC), total organic C (TOC) and extractable carbohydrates (TEC), total and inorganic N contents, soil basal respiration (SBR), soil microbial biomass C (MBC) and soil microbial biomass N (MBN), the substrate induced respiration (SIR) value, and enzyme activities involved in C, N, P and S mineralization. The TEC, total and inorganic N, SBR and microbial biochemical endpoints were higher in the de-sealed soils than those of an arable soil of the same area. The results show that de-sealed urban soils rapidly increase their physical, chemical and biological fertility even with no intervention, especially when they are colonized by volunteer plants.

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