Microbial and enzymatic activity in soil after organic composting

Microbial activity and biochemical properties are important indicators of the impact of organic composting on soil. The objective of this study was to evaluate some indicators of soil microbial and biochemical processes after application of compost (household waste). A Typic Acrustox, sampled at a depth of 10 cm under Cerrado biome vegetation, was evaluated in three treatments: control (soil without organic compost amendment) and soil with two doses of domestic organic compost (10 and 20 g kg-1 soil). The following properties were evaluated: released C (C-CO2): microbial respiration 15 days after incubation; microbial biomass C (MBC); total glucose (TG); metabolic quotient (qCO2); and enzyme activity of β-glucosidase and acid and alkaline phosphatase. The application of household compost, at doses of 10 and 20 g kg-1 Typic Acrustox, resulted in significant gains in microbial activity, organic C and C stock, as evidenced by increased MBC and TG levels. On the other hand, qCO2 decreases indicated greater microbial diversity and more efficient energy use. The addition of compost, particularly the 20 g kg-1 dose, strongly influenced the enzyme β-glucosidase and phosphatase (acid and alkaline). The β-glucosidase activity was significantly increased and acid phosphatase activity increased more than the alkaline. The ratio of β-glucosidase to MBC was greater in the control than in the composted treatments which suggests that there were more enzymes in the control than in the substrate or that the addition of compost induced a great MBC increase.

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Total C and N storage and organic C pools of a Red-Yellow Podzolic under conventional and no tillage at the Atlantic Forest Zone, south-eastern Brazil

Soil Research ◽

10.1071/sr02037 ◽

2003 ◽

Vol 41 (4) ◽

pp. 717 ◽

Cited By ~ 34

Author(s):

L. F. C. Leite ◽

E. S. Mendonça ◽

P. L. O. A. Machado ◽

E. S. Matos

Keyword(s):

Organic Carbon ◽

Atlantic Forest ◽

Soil Management ◽

Microbial Biomass C ◽

No Tillage ◽

Forest Zone ◽

Organic C ◽

C Stocks ◽

C And N ◽

The Impact

A 15-year experiment in a clayey Red-Yellow Podzolic in the tropical highlands of Viçosa, Brazil, was studied in 2000, aiming to evaluate the impact of different management systems (no tillage, disk plowing, heavy scratcher + disk plowing, and heavy scratched) on the total organic carbon (TOC), total nitrogen (TN), and several organic carbon pools. A natural forest, adjacent to the experimental area, was used as reference. The greatest TOC and TN as well as microbial biomass C (CMB), light fraction C (CFL), and labile organic carbon (CL) stocks were observed in the Atlantic Forest, compared with all other systems. The long-term cultivation (±70 years) of this area, prior to the installation of the experiment, has led to soil degradation, slowing the C recovery. No tillage had the higher C and N stocks and greater CL pool at the surface (0–10 cm), indicating improvement in soil nutrient status, although none of the systems presented potential to sequester C-CO2. Sustainable tropical agricultural systems should involve high residue input and conservative soil management in order to act as a C-CO2 sink. The C stocks in the CMB, CFL, and CL compartments were more reduced in relation to the natural vegetation with higher intensity management than the TOC stocks. This result indicates that these C compartments are more sensitive to changes in the soil management.

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Are researchers following best storage practices for measuring soil biochemical properties?

SOIL ◽

10.5194/soil-7-95-2021 ◽

2021 ◽

Vol 7 (1) ◽

pp. 95-106

Author(s):

Jennifer M. Rhymes ◽

Irene Cordero ◽

Mathilde Chomel ◽

Jocelyn M. Lavallee ◽

Angela L. Straathof ◽

...

Keyword(s):

Soil Properties ◽

Best Practice ◽

Storage Temperature ◽

Soil Depth ◽

Inorganic Nitrogen ◽

Biochemical Properties ◽

Microbial Biomass C ◽

Soil Extracts ◽

Organic C ◽

C And N

Abstract. It is widely accepted that the measurement of organic and inorganic forms of carbon (C) and nitrogen (N) in soils should be performed on fresh extracts taken from fresh soil samples. However, this is often not possible, and it is common practice to store samples (soils and/or extracts), despite a lack of guidance on best practice. We utilised a case study on a temperate grassland soil taken from different depths to demonstrate how differences in soil and/or soil extract storage temperature (4 or −20 ∘C) and duration can influence sample integrity for the quantification of soil-dissolved organic C and N (DOC and DON), extractable inorganic nitrogen (NH4+ and NO3-) and microbial biomass C and N (MBC and MBN). The appropriateness of different storage treatments varied between topsoils and subsoils, highlighting the need to consider appropriate storage methods based on soil depth and soil properties. In general, we found that storing soils and extracts by freezing at −20 ∘C was least effective at maintaining measured values of fresh material, whilst refrigerating (4 ∘C) soils for less than a week for DOC and DON and up to a year for MBC and MBN and refrigerating soil extracts for less than a week for NH4+ and NO3- did not jeopardise sample integrity. We discuss and provide the appropriate tools to ensure researchers consider best storage practice methods when designing and organising ecological research involving assessments of soil properties related to C and N cycling. We encourage researchers to use standardised methods where possible and to report their storage treatment (i.e. temperature, duration) when publishing findings on aspects of soil and ecosystem functioning. In the absence of published storage recommendations for a given soil type, we encourage researchers to conduct a pilot study and publish their findings.

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Soil Biochemical Indicators and Biological Fertility in Agricultural Soils: A Case Study from Northern Italy

Minerals ◽

10.3390/min11020219 ◽

2021 ◽

Vol 11 (2) ◽

pp. 219

Author(s):

Livia Vittori Antisari ◽

Chiara Ferronato ◽

Mauro De Feudis ◽

Claudio Natali ◽

Gianluca Bianchini ◽

...

Keyword(s):

Soil Degradation ◽

Crop Production ◽

Microbial Respiration ◽

Soil Analysis ◽

Energy State ◽

Biochemical Properties ◽

Microbial Biomass C ◽

Plant Nutrient ◽

Organic C ◽

Nutrient Contents

Industrial farming without considering soil biological features could lead to soil degradation. We aimed to evaluate the biochemical properties (BPs) and biological fertility (BF) of different soils under processing tomato cultivation; estimate the BF through the calculation of a simplified BF index (BFIs); determine if the crop was affected by BP and BF. Three farms were individuated in Modena (MO), Ferrara (MEZ) and Ravenna (RA) provinces, Italy. Soil analysis included total and labile organic C, microbial biomass-C (Cmic) and microbial respiration measurements. The metabolic (qCO2), mineralization (qM) and microbial (qMIC) quotients, and BFIs were calculated. Furthermore, plant nutrient contents were determined. The low Cmic content and qMIC, and high qCO2 found in MEZ soils indicate the occurrence of stressful conditions. The high qMIC and qM, and the low qCO2 demonstrated an efficient organic carbon incorporation as Cmic in MO soils. In RA soils, the low total and labile organic C contents limited the Cmic and microbial respiration. Therefore, as confirmed by the BFIs, while MO showed the healthiest soils, RA soils had an inefficient ecophysiological energy state. However, no effects on plant nutrient contents were observed, likely because of masked by fertigation. Finally, BP monitoring is needed in order to avoid soil degradation and, in turn, crop production decline.

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Microbial activity and survival in soils dried at different rates

Soil Research ◽

10.1071/sr9920209 ◽

1992 ◽

Vol 30 (2) ◽

pp. 209 ◽

Cited By ~ 50

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.

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The Effects of pH Change through Liming on Soil N2O Emissions

Processes ◽

10.3390/pr8060702 ◽

2020 ◽

Vol 8 (6) ◽

pp. 702

Author(s):

Muhammad Shaaban ◽

Yupeng Wu ◽

Lei Wu ◽

Ronggui Hu ◽

Aneela Younas ◽

...

Keyword(s):

Soil Ph ◽

Agricultural Soils ◽

Microbial Biomass C ◽

N2o Emissions ◽

Acidic Soils ◽

Emission Mitigation ◽

Ph Change ◽

Mineral N ◽

Organic C ◽

The Impact

Nitrous oxide (N2O) is an overwhelming greenhouse gas and agricultural soils, particularly acidic soils, are the main source of its release to the atmosphere. To ameliorate acidic soil condition, liming materials are added as an amendment. However, the impact of liming materials has not been well addressed in terms of exploring the effect of soil pH change on N2O emissions. In the present study, a soil with pH 5.35 was amended with liming materials (CaMg(CO3)2, CaCO3, Ca(OH)2 and CaO) to investigate their effects on N2O emissions. The results indicate that application of liming materials reduced the magnitudes of N2O emissions. The maximum reduction of soil N2O emissions took place for Ca(OH)2 treatment when compared to the other liming materials, and was related to increasing soil pH. Mineral N, dissolved organic C, and microbial biomass C were also influenced by liming materials, but the trend was inconsistent to the soil pH change. The results suggest that N2O emission mitigation is more dependent on soil pH than C and N dynamics when comparing the different liming materials. Moreover, ameliorating soil acidity is a promising option to mitigate N2O emissions from acidic soils.

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Are researchers following best storage practices for measuring soil biochemical properties?

10.5194/soil-2020-79 ◽

2020 ◽

Author(s):

Jennifer M. Rhymes ◽

Irene Cordero ◽

Mathilde Chomel ◽

Jocelyn M. Lavallee ◽

Angela L. Straathof ◽

...

Keyword(s):

Best Practice ◽

Inorganic Nitrogen ◽

Soil Extract ◽

Biochemical Properties ◽

Microbial Biomass C ◽

Organic C ◽

C And N ◽

C And N Cycling ◽

Forms Of Carbon ◽

Practice Methods

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Salinity affects the response of soil microbial activity and biomass to addition of carbon and nitrogen

Soil Research ◽

10.1071/sr12191 ◽

2013 ◽

Vol 51 (1) ◽

pp. 68 ◽

Cited By ~ 16

Author(s):

Manpreet S. Mavi ◽

Petra Marschner

Keyword(s):

Wheat Straw ◽

Microbial Activity ◽

Negative Impact ◽

Soil Microbial Activity ◽

Microbial Biomass C ◽

Organic C ◽

Soil Microbial ◽

C And N ◽

Microbial Tolerance ◽

Tolerance To Salinity

Addition of carbon (C) and nitrogen (N) to soil can enhance microbial tolerance to salinity, but it is not known if salinity changes the response of microbial activity and biomass to addition of C and N, or how nutrient addition affects microbial tolerance to salinity. We prepared salinity treatments of non-saline soil [electrical conductivity (EC1 : 5) 0.1 dS m–1] without salt addition or adjusted to four salinity levels (2.5, 5.0, 7.5, 10 dS m–1) using a combination of CaCl2 and NaCl. The soils were amended with 2.5 mg C g–1 as glucose or as mature wheat straw (C/N ratio 47 : 1), with NH4Cl added to glucose to achieve a C/N ratio similar to that of wheat straw, or with NH4Cl added to glucose or wheat straw to achieve a C/N ratio of 20. Soil respiration was measured over 30 days. Microbial biomass C and N (MBC, MBN), dissolved organic C (DOC), and total dissolved N (TDN) were measured on day 30. Cumulative respiration and MBC concentration decreased with increasing EC, less so with glucose than with wheat straw. The MBC concentration was more sensitive to EC than was cumulative respiration, irrespective of C source. Addition of N to glucose and wheat straw to bring the C/N ratio to 20 significantly decreased cumulative respiration and MBC concentration at a given EC. This study showed that in the short term, addition of a readily available and easily decomposable source of energy improves the ability of microbes to tolerate salinity. The results also suggest that in saline soils, irrespective of the C substrate, N addition has no impact, or a negative impact, on microbial activity and growth.

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Impact of burn severity on soil properties in a Pinus pinaster ecosystem immediately after fire

International Journal of Wildland Fire ◽

10.1071/wf18103 ◽

2019 ◽

Vol 28 (5) ◽

pp. 354 ◽

Cited By ~ 5

Author(s):

Víctor Fernández-García ◽

Elena Marcos ◽

José Manuel Fernández-Guisuraga ◽

Angela Taboada ◽

Susana Suárez-Seoane ◽

...

Keyword(s):

Microbial Biomass ◽

Soil Properties ◽

Pinus Pinaster ◽

C:N Ratio ◽

Burn Severity ◽

Available P ◽

Microbial Biomass C ◽

Total N ◽

Organic C ◽

The Impact

We analyse the effects of burn severity on individual soil properties and soil quotients in Mediterranean fire-prone pine forests immediately after a wildfire. Burn severity was measured in the field through the substrate stratum of the Composite Burn Index and soil samples were taken 7–9 days after a wildfire occurred in a Pinus pinaster Ait. ecosystem. In each soil sample, we analysed physical (size of soil aggregates), chemical (pH, organic C, total N and available P) and biological (microbial biomass C, β-glucosidase, urease and acid phosphatase activities) properties. Size of aggregates decreased in the areas affected by high burn severity. Additionally, moderate and high severities were associated with increases in pH and available P concentration and with decreases in organic C concentration. Microbial biomass C showed similar patterns to organic C along the burn severity gradient. The enzymatic activities of phosphatase and β-glucosidase showed the highest sensitivity to burn severity, as they strongly decreased from the low-severity scenarios. Among the studied soil quotients, the C:N ratio, microbial quotient and β-glucosidase:microbial biomass C quotient decreased with burn severity. This work provides valuable information on the impact of burn severity on the functioning of sandy siliceous soils in fire-prone pine ecosystems.

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Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

Sustainability ◽

10.3390/su13041595 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1595

Author(s):

Valeria Todeschi ◽

Roberto Boghetti ◽

Jérôme H. Kämpf ◽

Guglielmina Mutani

Keyword(s):

Machine Learning ◽

Energy Use ◽

Residential Buildings ◽

Building Energy ◽

Energy Performance ◽

Space Heating ◽

Engineering Model ◽

Building Energy Use ◽

The Impact ◽

The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

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Soil stripping and replacement for the rehabilitation of bauxite-mined land at Weipa. I. Initial changes to soil organic matter and related parameters

Soil Research ◽

10.1071/sr99043 ◽

2000 ◽

Vol 38 (2) ◽

pp. 345 ◽

Cited By ~ 18

Author(s):

G. D. Schwenke ◽

D. R. Mulligan ◽

L. C. Bell

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Field Experiments ◽

Surface Soil ◽

Soil Disturbance ◽

Microbial Biomass C ◽

Low Grade ◽

Double Pass ◽

Organic C ◽

The Difference

At Weipa, in Queensland, Australia, sown tree and shrub species sometimes fail to establish on bauxite-mined land, possibly because surface-soil organic matter declines during soil stripping and replacement. We devised 2 field experiments to investigate the links between soil rehabilitation operations, organic matter decline, and revegetation failure. Experiment 1 compared two routinely practiced operations, dual-strip (DS) and stockpile soil, with double-pass (DP), an alternative method, and subsoil only, an occasional result of the DS operation. Other treatments included variations in stripping-time, ripping-time, fertiliser rate, and cultivation. Dilution of topsoil with subsoil, low-grade bauxite, and ironstone accounted for the 46% decline of surface-soil (0–10 cm) organic C in DS compared with pre-strip soil. In contrast, organic C in the surface-soil (0–10 cm) of DP plots (25.0 t/ha) closely resembled the pre-strip area (28.6 t/ha). However, profile (0–60 cm) organic C did not differ between DS (91.5 t/ha), DP (107 t/ha), and pre-strip soil (89.9 t/ha). Eighteen months after plots were sown with native vegetation, surface-soil (0–10 cm) organic C had declined by an average of 9% across all plots. In Experiment 2, we measured the potential for post-rehabilitation decline of organic matter in hand-stripped and replaced soil columns that simulated the DS operation. Soils were incubated in situ without organic inputs. After 1 year’s incubation, organic C had declined by up to 26% and microbial biomass C by up to 61%. The difference in organic C decline between vegetated replaced soils (Expt 1) and bare replaced soils (Expt 2) showed that organic inputs affect levels of organic matter more than soil disturbance. Where topsoil was replaced at the top of the profile (DP) and not ploughed, inputs from volunteer native grasses balanced oxidation losses and organic C levels did not decline.

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