Microbial biomass and activity in litter during the initial development of pure and mixed plantations of Eucalyptus grandis and Acacia mangium

Studies on microbial activity and biomass in forestry plantations often overlook the role of litter, typically focusing instead on soil nutrient contents to explain plant and microorganism development. However, since the litter is a significant source of recycled nutrients that affect nutrient dynamics in the soil, litter composition may be more strongly correlated with forest growth and development than soil nutrient contents. This study aimed to test this hypothesis by examining correlations between soil C, N, and P; litter C, N, P, lignin content, and polyphenol content; and microbial biomass and activity in pure and mixed second-rotation plantations of Eucalyptus grandis and Acacia mangium before and after senescent leaf drop. The numbers of cultivable fungi and bacteria were also estimated. All properties were correlated with litter C, N, P, lignin and polyphenols, and with soil C and N. We found higher microbial activity (CO2 evolution) in litter than in soil. In the E. grandis monoculture before senescent leaf drop, microbial biomass C was 46 % higher in litter than in soil. After leaf drop, this difference decreased to 16 %. In A. mangium plantations, however, microbial biomass C was lower in litter than in soil both before and after leaf drop. Microbial biomass N of litter was approximately 94 % greater than that of the soil in summer and winter in all plantations. The number of cultivable fungi and bacteria increased after leaf drop, especially so in the litter. Fungi were also more abundant in the E. grandis litter. In general, the A. mangium monoculture was associated with higher levels of litter lignin and N, especially after leaf drop. In contrast, the polyphenol and C levels in E. grandis monoculture litter were higher after leaf drop. These properties were negatively correlated with total soil C and N. Litter in the mixed stands had lower C:N and C:P ratios and higher N, P, and C levels in the microbial biomass. This suggests more effective nutrient cycling in mixed plantations in the long term, greater stimulation of microbial activity in litter and soil, and a more sustainable system in general.

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Anaerobic Digestate Fraction and Nutrient Stoichiometry Significantly Influence the Carbon Cycle in Grassland Soils

10.5194/egusphere-egu2020-19459 ◽

2020 ◽

Author(s):

Marta Cattin ◽

Marc Stutter ◽

Alfonso Lag-Brotons ◽

Phil Wadley ◽

Kirk T. Semple ◽

...

Keyword(s):

Microbial Biomass ◽

Soil Ph ◽

Soil Nutrient ◽

Nutrient Status ◽

Microbial Biomass C ◽

Grassland Soils ◽

Soil Nutrient Status ◽

Soil C ◽

C Cycle ◽

Soil C Cycle

The application of digestate from anaerobic digestion to grassland soils is of growing interest as an agricultural practice. However, significant uncertainties surrounding the potential impacts of digestate application on processes associated with the soil microbial community remain, particularly for processes governing Carbon Use Efficiency (CUE) and the broader soil C cycle. In this research, we examined how the C:N stoichiometry of digestate and the nutrient status of soil influenced the impact of digestate application on the soil C cycle. &#160;Three fractions of digestate (whole [WD], solid [SD] and liquid [LD]), spanning a range of C:N, were each applied to two soils of contrasting starting nutrient status (high and low) and compared to unamended controls (Ctr). Two short-term incubations, each lasting seven days, were undertaken. In the first, applications of WD, SD and LD each achieved the same total N input to soils. In the second, digestate applications were adjusted to provide consistent total C input to soils. In each incubation, CO2-C efflux, microbial biomass C (Cmicro) and pH were determined. &#160;In each of the two incubations, the application of digestate significantly increased cumulative CO2-C efflux compared to control soils. However, the precise effect of digestate application varied between the two incubations and with both soil nutrient status and digestate fraction. Microbial biomass C was largely unchanged by the treatments in both incubations. During the first incubation, soil pH decreased substantially following each digestate treatment in both soil types. A similar pattern was observed within the second incubation in the high nutrient soil. However, in contrast, soil pH increased substantially following LD and WD application to the low nutrient soil in the second incubation. Varying CUE responses are likely to be observed following the application of digestate to agricultural soils, dependent on digestate fraction, C:N ratio of the digestate, and the initial soil nutrient status. Therefore, digestate application rates and soil management must be carefully planned in order to avoid adverse impacts of digestate application to land.&#160;&#160;

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Evaluation of the throughfall and stemflow nutrient contents in mixed and pure plantations of Acacia mangium, Pseudosamenea guachapele and Eucalyptus grandis

Revista Árvore ◽

10.1590/s0100-67622007000200017 ◽

2007 ◽

Vol 31 (2) ◽

pp. 339-346 ◽

Cited By ~ 7

Author(s):

Fabiano de Carvalho Balieiro ◽

Avílio Antônio Franco ◽

Renildes Lúcio Ferreira Fontes ◽

Luiz Eduardo Dias ◽

Eduardo Francia Carneiro Campello ◽

...

Keyword(s):

Forest Canopy ◽

Eucalyptus Grandis ◽

Acacia Mangium ◽

Tropical Soils ◽

Low Fertility ◽

Pure Stand ◽

Nitrogen Fixing ◽

Nutrient Input ◽

Nutrient Contents ◽

Mixed Plantations

The interception of the rainfall by the forest canopy has great relevance to the nutrient geochemistry cycle in low fertility tropical soils under native or cultivated forests. However, little is known about the modification of the rainfall water quality and hydrological balance after interception by the canopies of eucalyptus under pure and mixed plantations with leguminous species, in Brazil. Samples of rainfall (RF), throughfall (TF) and stemflow (SF) were collected and analyzed in pure plantations of mangium (nitrogen fixing tree -NFT), guachapele (NFT) and eucalyptus (non-nitrogen fixing tree -NNFT) and in a mixed stand of guachapele and eucalyptus in Seropédica, State of Rio de Janeiro, Brazil. Nine stemflow collectors (in selected trees) and nine pluviometers were randomly disposed under each stand and three pluviometers were used to measure the incident rainfall during 5.5 months. Mangium conveyed 33.4% of the total rainfall for its stem. An estimative based on corrections for the average annual precipitation (1213 mm) indicated that the rainfall's contribution to the nutrient input (kg ha-1) was about 8.42; 0.95; 19.04; 6.74; 4.72 and 8.71 kg ha-1 of N-NH4+, P, K+, Ca+2, Mg+2 and Na+, respectively. Throughfall provided the largest contributions compared to the stemflow nutrient input. The largest inputs of N-NH4+ (15.03 kg ha-1) and K+ (179.43 kg ha-1) were observed under the guachapele crown. Large amounts of Na+ denote a high influence of the sea. Mangium was the most adapted species to water competitiveness. Comparatively to pure stand of eucalyptus, the mixed plantation intensifies the N, Ca and Mg leaching by the canopy, while the inputs of K and P were lower under these plantations.

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Microbial biomass C and alkaline phosphatase activity in two compost amended soils

Canadian Journal of Soil Science ◽

10.4141/s98-004 ◽

1998 ◽

Vol 78 (4) ◽

pp. 581-587 ◽

Cited By ~ 12

Author(s):

Roger Lalande ◽

Bernard Gagnon ◽

Régis R. Simard

Keyword(s):

Alkaline Phosphatase ◽

Microbial Biomass ◽

Phosphatase Activity ◽

Alkaline Phosphatase Activity ◽

Sandy Loam ◽

Biochemical Properties ◽

Climatic Conditions ◽

Microbial Biomass C ◽

Soil C ◽

Soil Biochemical Properties

Addition of compost from various sources and of different maturity may affect the soil biochemical properties. A field study was conducted to evaluate the effect of different composts, spring-applied alone or in combination with ammonium nitrate (AN), on microbial biomass C (MBC) and alkaline phosphatase activity (APA) in two soils cropped with spring wheat (Triticum aestivum L. 'Messier') in eastern Quebec, Canada. The experiment was conducted in 1994 and 1995 at different sites on a Kamouraska clay (Orthic Humic Gleysol) and a Saint-André sandy loam (Fragic Humo-Ferric Podzol). Treatments included composts at 180 kg N ha−1, composts at 90 kg N ha−1 supplemented with AN, AN at 90 kg N ha−1, and an unfertilized control. Soil MBC and APA were measured 30 d after compost application and at wheat harvest. Additional sampling was made the following spring. Generally, larger MBC and APA values were found at wheat harvest in soils treated with composts alone than with AN alone or unfertilized. These effects were related to soil C content and climatic conditions. Compost type affected soil biochemical properties which could be attributed to the total C supply and material maturation state. Compost addition constitutes an efficient short-term way to promote soil microbial biomass and enzyme activity in cold climates. Key words: Compost, fertilizer, microbial biomass, soil enzyme, wheat

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How do microorganisms from permafrost soils respond to short-term warming?

10.5194/egusphere-egu2020-13452 ◽

2020 ◽

Author(s):

Victoria Martin ◽

Julia Wagner ◽

Niek Speetjens ◽

Rachele Lodi ◽

Julia Horak ◽

...

Keyword(s):

Microbial Biomass ◽

Microbial Activity ◽

Soil Microbes ◽

Heterotrophic Respiration ◽

Microbial Biomass C ◽

Current View ◽

Short Term ◽

Organic Layers ◽

Global Rate ◽

Permafrost Soils

Arctic ecosystems outpace the global rate of temperature increases and are exceptionally susceptible to global warming. Concerns are raising that CO2 and CH4 released from thawing permafrost upon warming may induce a positive feedback to climate change. This is based on the assumption, that microbial activity increases with warming and does not acclimate over time. However, we lack a mechanistic understanding of carbon and nutrient fluxes including their spatial control in the very heterogeneous Arctic landscape. The objective of this study therefore was to elucidate the microbial controls over soil organic matter decomposition in different horizons of the active layer and upper permafrost. We investigated different landscape units (high-centre polygons, low-centre polygons and flat polygon tundra) in two small catchments that differ in glacial history, at the Yukon coast, Northwestern Canada.In total, 81 soil samples were subjected to short-term (eight weeks) incubation experiments at controlled temperature (4 &#176;C and 14 &#176;C) and moisture conditions. Heterotrophic respiration was assessed weekly, whereas physiological parameters of soil microbes and their temperature response (Q10) were determined at the end of the incubation period. Microbial growth was estimated by measuring the incorporation of 18O from labelled water into DNA and used to calculate microbial carbon use efficiencies (CUE). Microbial biomass was determined via chloroform fumigation extraction. Potential activities of extracellular enzymes involved in C, N, P and S cycling were measured using microplate fluorimetric assays.Cumulative heterotrophic respiration of investigated soil layers followed the pattern organic layers > upper frozen permafrost > cryoturbated material > mineral layers in both catchments. Microbial respiration responded strongly in all soils to warming in all soils, but the observed response was highest for organic layers and cryoturbated material at the beginning and end of the experiment. Average Q10 values at the beginning of the experiment varied between 1.7 to 4.3 with differences between horizons but converged towards Q10 values between 2.0min to 2.9max after eight weeks of incubation. Even though microbial biomass C did not change with warming, microbial mass specific growth was enhanced in organic, cryoturbated and permafrost soils. Overall, warming resulted in a 65% reduced CUE in organic horizons.Our results show no indication for physiological acclimatization of permafrost soil microbes when subjected to 8-weeks of experimental warming. Given that the duration of the season in which most horizons are unfrozen is rarely longer than 2 months, our results do not support an acclimation of microbial activity under natural conditions. Instead, our data supports the current view of a high potential for prolonged carbon losses from tundra soils with warming by enhanced microbial activity.This work is part of the EU H2020 project &#8220;Nunataryuk&#8221;.

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

Soil Research ◽

10.1071/sr18017 ◽

2018 ◽

Vol 56 (6) ◽

pp. 623 ◽

Cited By ~ 5

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.

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Nutrient relations during an eucalyptus cycle at different population densities

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832011000300029 ◽

2011 ◽

Vol 35 (3) ◽

pp. 949-959 ◽

Cited By ~ 13

Author(s):

Fernando Palha Leite ◽

Ivo Ribeiro Silva ◽

Roberto Ferreira Novais ◽

Nairam Félix de Barros ◽

Júlio César Lima Neves ◽

...

Keyword(s):

Forest Floor ◽

Nutrient Dynamics ◽

Management Practices ◽

Eucalyptus Grandis ◽

Soil Nutrient ◽

Santa Barbara ◽

Nutrient Contents ◽

Tree Population ◽

Biomass Components ◽

Nutrient Relations

To synchronize nutrient availability with the requirements of eucalyptus during a cultivation cycle, the nutrient flow of this system must be well understood. Essential, for example, is information about nutrient dynamics in eucalyptus plantations throughout a cultivation cycle, as well as impacts on soil nutrient reserves caused by the accumulation and subsequent export of nutrients via biomass. It is also important to quantify the effect of some management practices, such as tree population density (PD) on these fluxes. Some nutrient relations in an experiment with Eucalyptus grandis, grown at different PDs in Santa Barbara, state of Minas Gerais, Brazil, were evaluated for one cultivation cycle. At forest ages of 0.25, 2.5, 4.5, and 6.75 years, evaluations were carried out in the stands at seven different PDs (between 500 and 5,000 trees ha-1) which consisted in chemical analyses of plant tissue sampled from components of the aboveground parts of the tree, from the forest floor and the litterfall. Nutrient contents and allocations of the different biomass components were estimated. In general, there were only small and statistically insignificant effects of PD on the nutrient concentration in trees. With increasing forest age, P, K, Ca and Mg concentrations were reduced in the aboveground components and the forest floor. The magnitud of biochemical nutrient cycling followed the sequence: P > K > N > Mg. At the end of the cycle, the quantities of N, P, Ca and Mg immobilized in the forest floor were higher than in the other components.

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Pore size effect on soil carbon dynamics during decomposition of switchgrass

10.5194/egusphere-egu2020-1148 ◽

2020 ◽

Author(s):

Kyungmin Kim ◽

Andrey Guber ◽

Alexandra Kravchenko

Keyword(s):

Microbial Biomass ◽

Pore Size ◽

Microbial Activity ◽

Priming Effect ◽

Pore Space ◽

Phenol Oxidase ◽

Physical Factors ◽

Soil System ◽

Soil C ◽

C Cycle

Soil pore size distribution (PSD) regulates oxygen diffusion and transport of water/mineralized nutrients. Microbial activity, which drives the carbon (C) cycle in the soil system, can react to these physical factors regulated by PSD. In this study, we investigated the contribution of PSD to C-related microbial activity during the switchgrass decomposition. We used two types of soils, which have controlled PSD (dominant pore size of < 10um and > 30 um). 13C labeled switchgrass leaf and root were incorporated into different PSD of soils and incubated for 21 days under 50% water-filled pore space. During the incubation, microbial activity was assessed with several indicators. i) Fate and transport of mineralized switchgrass, ii) Priming effect, iii) Spatial distribution of b-glucosidase and phenol oxidase, and iv) Microbial biomass. Our preliminary results showed that CO2 emission from switchgrass leaf was greater in the soil dominated by < 10 um pores. Higher b -glucosidase activity and mineralized C from switchgrass leaf supported greater C-related activity in such soil. However, interestingly, we observed a greater priming effect in the soil dominated by > 30 um pores. Due to the less mineralization and transport of switchgrass-derived C in such pores, enzymes targeting more complex substrate could be more active in such soil stimulating mineralization of native soil C. Our full results of phenol oxidase, microbial biomass, and more detailed analysis on 13C and C dynamics will help understanding how PSD can affect biochemical reactions in plant decomposition system.

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Soil C extracted with water or K2SO4: pH effect on determination of microbial biomass

Canadian Journal of Soil Science ◽

10.4141/s99-011 ◽

1999 ◽

Vol 79 (4) ◽

pp. 529-533 ◽

Cited By ~ 22

Author(s):

R. L. Haney ◽

A. J. Franzluebbers ◽

F. M. Hons ◽

D. A. Zuberer

Keyword(s):

Microbial Biomass ◽

Ph Effect ◽

Calcareous Soils ◽

Microbial Biomass C ◽

Soil C ◽

Soil Microbial ◽

The Past ◽

Chloroform Fumigation ◽

Fumigation Extraction

Routine determination of soil microbial biomass C has shifted during the past decade from chloroform fumigation-incubation to chloroform fumigation-extraction using 0.5 M K2SO4 as extractant. We compared extractable C with water and 0.5 M K2SO4 in eight soils ranging in pH from 5.4 to 8.3. In unfumigated soils with low pH, extractable C was 0.8- to 1.2-fold greater with water than with 0.5 M K2SO4. However, in unfumigated soils with pH > 7.7, extractable C, although not statistically significant, was 11 to 19% less with water than with 0.5 M K2SO4. In fumigated soils, no difference in extractable C between water and 0.5 M K2SO4 was detected among soils with pH < 7.7, but extractable C was 13 to 17% less with water than with 0.5 M K2SO4 with pH > 7.7. Our results suggest that 0.5 M K2SO4 (1) may flocculate soil and cause adsorption of solubilized C onto colloids at pH < 7.7, but (2) may disperse calcareous soils at pH > 7.7, thereby differentially affecting the fate of solubilized C depending upon soil pH. Our results put into question the widespread adaptability of using chloroform fumigation-extraction to estimate microbial biomass C. Key words: Extractable carbon, chloroform fumigation-extraction, microbial biomass

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Contrasting responses of soil phosphatase activity to nitrogen and phosphorus loadings: Implications for phosphorus management

10.5194/egusphere-egu21-1655 ◽

2021 ◽

Author(s):

Ji Chen ◽

Yiqi Luo ◽

Junji Cao ◽

Uffe Jørgensen ◽

Daryl Moorhead ◽

...

Keyword(s):

Microbial Biomass ◽

Phosphatase Activity ◽

Soil Ph ◽

Meta Analysis ◽

Integrated Control ◽

Microbial Biomass C ◽

Nitrogen And Phosphorus ◽

Soil C ◽

P Limitation ◽

Soil Phosphatase

Human activity has caused imbalances in nitrogen (+N) and phosphorus (+P) loadings of ecosystems around the world, causing widespread P limitation of many biological processes. Soil phosphatases catalyze the hydrolysis of P from a range of organic compounds, representing an important P acquisition pathway. Therefore, a better understanding of soil phosphatase activity as well as the underlying mechanisms to individual and combined N and P loadings could provide fresh insights for wise P management. Here we show, using a meta-analysis of 188 published studies and 1277 observations that +N significantly increased soil phosphatase activity by 14%, +P significantly repressed it by 30%, and +N+P led to non-significant responses of soil phosphatase activity. Responses of soil phosphatase activity to +N were positively correlated with soil C and N content, whereas the reverse relationships were observed for +P and +N+P. Similarly, effects of +N on soil phosphatase activity were positively related to microbial biomass C, microbial biomass C:P, and microbial biomass N:P, whereas reverse relationships were observed for +P. Although we found no clear relationship between soil pH and soil phosphatase activity, +N-induced reductions in soil pH were positively correlated with soil phosphatase activity. Our results underscore the integrated control of soil and microbial C, N and P stoichiometry on the responses of soil phosphatase activity to +N, +P, and +N+P, which can be used to optimize future P management.

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Application of Different Fractions of Anaerobic Digestate Significantly Influences the Carbon Cycle in Grassland Soils

10.5194/egusphere-egu2020-9510 ◽

2020 ◽

Author(s):

Marta Cattin ◽

Kirk T. Semple ◽

Marc Stutter ◽

Gaetano Romano ◽

Alfonso Lag-Brotons ◽

...

Keyword(s):

Phospholipid Fatty Acid ◽

Soil Nutrient ◽

Nutrient Status ◽

Nutrient Content ◽

Microbial Biomass C ◽

Grassland Soils ◽

Soil C ◽

Application Rates ◽

C Stocks ◽

High Nutrient

Applying digestate to soil is of growing interest in agriculture. However, the impacts of digestate on soil biogeochemical cycles often remain unclear, especially after solid-liquid separation of whole digestate (WD). We used a 21 d incubation to examine the effects of WD and solid digestate (SD) on CO2-C efflux, dissolved organic carbon (DOC), microbial biomass C (Cmicro), phospholipid fatty acid (PLFA) and carbon use efficiency (CUE) within two grassland soils of contrasting nutrient status. Application rates for SD and WD were based on recommended N inputs to grassland soils for these organic materials. Compared to un-amended controls, cumulative CO2-C efflux, Cmicro and the fungal:bacterial in soils increased significantly following SD application, regardless of the soil nutrient content (+20% CO2-C, +29% Cmicro, +58% fungal:bacteria for high nutrient soil; +563% CO2-C, +36% Cmicro, +18% fungal:bacteria for low nutrient soil). In contrast, WD produced a significant effect on CO2-C efflux and fungal:bacterial only in the low nutrient soil. Our results also indicated that both digestate fractions and the initial soil nutrient status affected CUE. Applying both SD and WD to a low nutrient soil potential leads to decreases in soil C stocks, whilst the application of SD to a high nutrient soil can potentially enhance soil C stocks. Digestate application must be carefully planned, accounting for both the nature of the digestate and of the soil, in order to avoid adverse impacts on soil C stocks.&#160;

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