Land use effect on microbial growth and respiration under future climate

Author(s):  
Vusal Guliyev ◽  
Melissa Pfeiffer ◽  
Maria Udovenko ◽  
Christina Fasching ◽  
Thomas Reitz ◽  
...  

<p>Fresh input of organic material in soil is continuously transformed and processed by growing microorganisms using this organic input as a substrate. Therefore, the quality and quantity of soil organic C stock is strongly dependent on the intensity of mineralization processes through microbial respiration and growth. We aimed to prove the sensitivity of microbial respiration and growth parameters to indicate an interactive effect of land use and climate warming. For this we used Global Change Experimental Facility in Bad Lauchstädt, UFZ, Halle, Germany. This long-term experiment is designed in 5 land use strategies (Organic Farming, Conventional Farming, Intensive Meadow, Extensive Meadow, and Extensive Pasture) and 2 climate scenarios (ambient and future). We determined basal respiration by CO<sub>2</sub> emission, microbial growth parameters by substrate-induced growth respiration (SIGR), and the quality of soil organic matter by Fourier-transformed infrared spectroscopy (FTIR). The effect of biotic (vegetation type) and abiotic (temperature and moisture) factors on microbial attributes and on chemical composition of soil organic matter will be compared.</p>

2020 ◽  
Author(s):  
Carolina Merino ◽  
Francisco Matus ◽  
Yakov Kuzyakov ◽  
Ignacio Jofré ◽  
Francisco Najera

<p>Electron acceptors (NO<sub>3</sub><sup>–</sup>, SO<sub>4</sub><sup>2–</sup>, Fe<sup>3+</sup>, Mn<sup>4+</sup>) play a crucial function in the oxidation of soil recalcitrant organic compounds. Soils that present large amount of total Fe (8-57 g kg<sup>-1</sup>soil) and organic (C) (10-110 g kg<sup>-1</sup>soil), iron-reducing bacteria (IRB)  may play a importan role. In the present study we hypothesized that IRB which reduce Fe(III)(oxyhydr)oxide of low solubility to soluble Fe(II), can contribute substantially to the degradation of lignin from soil organic matter (SOM). The aim of this study was to isolate IRB and evaluate their importance in lignin degradation. IRB were obtained from topsoils of different climates (humid temperate, cold temperate, subpolar), vegetation type (steppe, rainforest) and parent materials (granitic, volcanic, fluvio-glacial, basaltic-Antartic and metamorphic). The potential of IRB to reduce Fe(III) was assessed with lactate substrate as source of carbon (C) and anthraquinone-2,6-disulfonate (AQDS) as electron acceptor. The contribution of IRB to lignin degradation was assessed in an anaerobic microcosms experiment for 36 h. The CO<sub>2</sub> efflux from sterilized and reinoculated soil with IRB was compared with sterilized (abiotic), non-sterilized (biotic) and induced Fenton reaction. Lignin degradation by IRB was examined by: 1) bacterial growth containing alkali lignin and alkali lignin disappearance during incubation, 2) Lignin peroxidase and manganese peroxidase activities originated from IRB, 3) cells abundance estimated from ATP synthase from bacteria growing in alkali lignin and 4) lignin degradation monitored by fluorescence disappearance intensity. The major microbial group for Fe(III) reduction, as essayed by PLFA and nested-PCR and sequencing different species were Geobactericeae-strains (G. metallireducens and G. lovleyi) in all studied. The CO<sub>2</sub> respiration in reinoculated soils was 140% higher than the CO<sub>2 </sub>release by abiotic and Fenton reaction and, 40% lower than biotic treated soil. The Fe(II) extractable in HCl in soil derived from basaltic-Antarctic parent material showed 362 % more Fe(II) solubilisation than that of biotic treatment. Fluorescence intensity decreased during lignin degradation and it was closely correlated with CO<sub>2</sub> release in the same sample. We conclude that IRB community such as Geobacter spp. Uses intensively Fe(III) as an electron acceptor to oxidize lignin compounds, and this process is especially active in Fe rich soils.</p>


2010 ◽  
Vol 34 (3) ◽  
pp. 907-916 ◽  
Author(s):  
Cícero Célio de Figueiredo ◽  
Dimas Vital Siqueira Resck ◽  
Marco Aurélio Carbone Carneiro

Soil organic matter can be analyzed on the basis of the different fractions. Changes in the levels of organic matter, caused by land use, can be better understood by alterations in the different compartments. The aim of this study was to evaluate the effect of different management systems on the labile and stable organic matter of a dystrophic Red Latosol (Oxisol). The following properties were determined: total organic C and total N (TOC and TN), particulate organic C and particulate N (POC and PN), organic C and N mineral-associated (MOC and NM) and particulate organic C associated with aggregate classes (POCA). Eight treatments were used: seven with soil management systems and one with native Cerrado as a reference. The experiment was designed to study the dynamics of systems of tillage and crop rotation, alternating in time and space. The experimental design was a randomized block design with three replications. The soil samples were collected from five depths: 0-5, 5-10, 10-20, 20-30 and 30-40 cm. Changes in organic C by land use occurred mainly in the fraction of particulate organic matter (> 53 mm). Proper management of grazing promoted increased levels of particulate organic matter by association with larger aggregates (2-8 mm), demonstrating the importance of the formation of this aggregate class for C protection in pasture.


2017 ◽  
pp. 55-66
Author(s):  
Jessa May Malanguis ◽  
Cheryl Batistel ◽  
Marlito Jose Bande

Land use conversion affects soil ecosystem quality and balance, which can be reflected by microbial activities. This study was conducted to assess the effectiveness of microbial respiration as indicator of soil quality of different land uses, reforestation site, agricultural land and grassland, in Cienda, Gabas, Baybay City, Leyte. The amount of CO2 evolved after one, three and seven days of incubation was used to determine microbial respiration rate of different land uses and across relief. Relationship between microbial respiration on pH, organic matter, total nitrogen, and moisture content at field capacity were also examined. Results revealed that microbial respiration varies significantly among land uses with the highest rate observed in grassland while the lowest was in the reforestation site. Across relief, amount of CO2 released was significantly higher in the lower slope compared to the upper and the middle. The process tends to be significantly influenced by soil organic matter and moisture content. Results suggest that there is an inverse relationship between microbial respiration and organic matter, and a direct relationship with moisture content. High soil respiration in the grassland and in the lower topographic relief implies that the soil organic matter is converted into inorganic forms which are available for uptake by plants. A significant interaction between land use types and relief was also observed in both organic matter and moisture content leading enhanced microbial respiration. Land use and relief showed no significant effect on total nitrogen and soil pH.


Soil Research ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 13 ◽  
Author(s):  
R. C. Dalal ◽  
B.P. Harms ◽  
E. Krull ◽  
W.J. Wang

Mulga (Acacia aneura) dominated vegetation originally occupied 11.2 Mha in Queensland, of which 12% has been cleared, mostly for pasture production, but some areas are also used for cereal cropping. Since mulga communities generally occupy fragile soils, mostly Kandosols and Tenosols, in semi-arid environments, clearing of mulga, which continues at a rate of at least 35 000 ha/year in Queensland, has considerable impact on soil organic carbon (C), and may also have implications for the greenhouse gas emissions associated with land use change in Australia. We report here the changes in soil C and labile C pools following mulga clearing to buffel pasture (Cenchrus ciliaris) and cereal (mostly wheat) cropping for 20 years in a study using paired sites. Soil organic C in the top 0.05 m of soil declined by 31% and 35% under buffel pasture and cropping, respectively. Land use change from mulga to buffel and cropping led to declines in soil organic C of 2.4 and 4.7 t/ha, respectively, from the top 0.3 m of soil. Using changes in the δ13C values of soil organic C as an approximate representation of C derived from C3 and C4 vegetation from mulga and buffel, respectively, up to 31% of soil C was C4-derived after 20 years of buffel pasture. The turnover rates of mulga-derived soil C ranged from 0.035/year in the 0–0.05 m depth to 0.008/year in the 0.6–1 m depths, with respective turnover times of 29 and 133 years. Soil organic matter quality, as measured by the proportion/amount of labile fraction C (light fraction, < 1.6 t/m3) declined by 55% throughout the soil profile (0–1 m depth) under both pasture and cropping. There is immediate concern for the long-term sustainable use of land where mulga has been cleared for pasture and/or cropping with a continuing decline in soil organic matter quality and, hence, soil fertility and biomass productivity. In addition, the removal of mulga forest over a 20-year period in Queensland for pasture and cropping may have contributed to the atmosphere at least 12 Mt CO2-equivalents.


Soil Research ◽  
2002 ◽  
Vol 40 (5) ◽  
pp. 859 ◽  
Author(s):  
D. S. Mendham ◽  
A. M. O'Connell ◽  
T. S. Grove

The influence of land-use management on Walkley-Black soil carbon (C) concentration, 3 concentrations of permanganate oxidisable C (33, 167, and 333 mm), microbial biomass, and soil respiration in a laboratory incubation was tested in surface soil from 10 sites in south-western Australia. The sites ranged in total C concentration from 1.9 to 8.3%, and represented a broad climatic and soil-type distribution across south-western Australia. At each of the sites, 0-10 cm soil was collected from plots in pasture (20-71 years old), Eucalyptus globulus plantation (7-10 years old, established on ex-pasture), and native vegetation. Soil profiles and position in the landscape for each of the land-use types were matched as closely as possible at each site to minimise influences other than land use. Total C was highly correlated with clay content. Land use caused no significant change in the relationship between total C and soil texture, and land use had little effect on total C concentration. Permanganate-oxidisable C was highly correlated with Walkley-Black organic C (R2�&gt;�0.90) for all 3 concentrations that were investigated. Only the most dilute concentration of permanganate-oxidisable C (33 mm) was sensitive enough to detect small changes in soil organic matter with land use (P = 0.045). Microbial biomass and respiration at 25 kPa matric potential moisture content and 35°C temperature were used as biological indicators of soil organic matter lability. Cumulative respired C was more sensitive to land use than Walkley-Black organic C, with lower respiration in native soils compared with managed soils with low C concentrations, but higher than the managed soils at sites with high C concentrations. Microbial biomass was not significantly affected by land use. Microbial biomass and cumulative respired C were strongly influenced by soil texture, with the microbial quotient (proportion of microbial biomass in total carbon) and the proportion of total C respired significantly lower in soils with higher silt and clay contents. Land use had no significant effect on these relationships. Overall, land use caused only minor differences in the biological and chemical indicators of organic matter quality across a broad range of sites in south-western Australia.


Soil Research ◽  
2005 ◽  
Vol 43 (2) ◽  
pp. 179 ◽  
Author(s):  
R. C. Dalal ◽  
B. P. Harms ◽  
E. Krull ◽  
W. J. Wang ◽  
N. J. Mathers

Mulga (Acacia aneura) woodlands and open forests occupy about 150 Mha in Australia, and originally occupied 11.2 Mha in Queensland. Substantial areas (1.3 Mha) of the mulga vegetation have been cleared in Queensland, mostly for pasture production, but some areas are also used for cereal cropping. Twenty years after mulga clearing we found a significant loss of total soil organic C (28–35% from the 0–0.05 m depth) and light fraction C (>50% from the 0–1 m depth) from soil under pasture and cropping at a site in southern Queensland. We report here the changes in soil N and labile N pools in a paired-site study following conversion of mulga to buffel pasture (Cenchrus ciliaris) and cereal (mostly wheat) cropping for more than 20 years. Conversion from mulga forest to pasture and cultivation resulted in greater losses of soil N than organic C in the top 0.1 m depths. As a result, C/N ratios in soil under both pasture and cropping were higher than soil under mulga, indicating a decline in soil organic matter quality after mulga clearing. Although land-use change had no significant effect on 15N natural abundance (δ15N) values of total soil N down to a depth of 1 m, δ15N values of wheat tops and roots indicated that the primary source of N under cropping was soil organic N, while that of buffel pasture was a mixed source of soil N and decomposed litter and root N. Light fraction N (<1.6 Mg/m3) declined by 60–70% throughout the 1 m soil profile under pasture and cropping, but it was 15N-enriched in these 2 land-use systems. The δ15N values of mulga phyllodes, twigs, and fine roots, indicated an input of atmospheric fixed N2 that was estimated to be about 25 kg N/ha.year. However, the source and magnitude of this N resource needs to be confirmed. Soil N losses were estimated to be 12 kg N/ha.year under pasture and 17 kg N/ha.year under cropping over a 20-year period. These findings raise the issue of the long-term sustainable use of cleared mulga areas for pasture and/or cropping. The labile C and N pools and N mineralised also declined, which would have an immediate adverse effect on soil fertility and plant productivity of cleared Mulga Lands, as well as reducing their potential as a soil sink for greenhouse gases.


Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 345 ◽  
Author(s):  
G. D. Schwenke ◽  
D. R. Mulligan ◽  
L. C. Bell

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.


1999 ◽  
Vol 79 (1) ◽  
pp. 103-109 ◽  
Author(s):  
F. Courchesne ◽  
J.-F. Laberge ◽  
A. Dufresne

The role of soil organic matter (OM) on SO4 retention was investigated by comparing OM content, SO4 retention, and the distribution of Fe, Al and Si compounds in OM-poor (Grands-Jardins, PGJ) and OM-rich (Hermine, HER) Podzols from Québec, Canada. At both sites, four pedons were sampled by horizon; soil pH in H2O, organic C, phosphate-extractable SO4 and, sodium pyrophosphate, acid ammonium oxalate and dithionite-citrate-bicarbonate (DCB) extractable Fe, Al and Si were measured for each mineral horizon. The mineralogy of the clay (<2 µm) and fine silt (2–20 µm) fractions of selected horizons was determined by X-ray diffraction (XRD) and infrared spectroscopy (IR). Weighted mean organic C and pyrophosphate extractable Fe and Al contents were significantly higher in the HER than in the PGJ sola, while the PGJ soils were richer in amorphous inorganic Al. No trends were observed for inorganic Fe compounds. Chemical dissolution and IR allowed the identification of short-range ordered aluminosilicates, probably allophane, in the OM-poor and slightly acidic to neutral PGJ soils. These materials were absent from the OM-rich and acidic HER soils. Phosphate extractions showed that the weighted mean native SO4 content was five times higher in the PGJ than in the HER soil. Finally, native SO4 was strongly related to inorganic Fe, Al and Si (associated with allophane) at PGJ but only to inorganic Fe at HER. These results indicate that OM indirectly affects SO4 sorption through the influence organic substances exerts on the nature and distribution of pedogenic Fe, Al and Si compounds, such as allophane, in Podzolic profiles. Key words: Organic matter, sulfate, imogolite, allophane, silica, Podzol


2021 ◽  
Author(s):  
Anna Schneider ◽  
Alexander Bonhage ◽  
Florian Hirsch ◽  
Alexandra Raab ◽  
Thomas Raab

&lt;p&gt;Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.&lt;/p&gt;&lt;p&gt;We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils.&amp;#160;The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.&lt;/p&gt;


HortScience ◽  
2017 ◽  
Vol 52 (6) ◽  
pp. 896-904 ◽  
Author(s):  
Rebecca J. Long ◽  
Rebecca N. Brown ◽  
José A. Amador

Using organic wastes as agricultural amendments is a productive alternative to disposal in landfills, providing nutrients for plant growth and carbon to build soil organic matter. Despite these benefits, a large fraction of organic waste is sent to landfills. Obstacles to the adoption of wastes as sources of plant nutrients include questions about harmful effects to crops or soils and the wastes’ ability to produce satisfactory yields. We compared six organic waste amendments with a mineral fertilizer control (CN) to determine effects on soil quality, soil fertility, crop quality, and crop yield in 2013 and 2014. Waste amendments were applied at a rate sufficient to supply 10,000 kg organic C/ha over two seasons, and mineral fertilizer was applied to control plots to provide 112 kg-N/ha/yr. The experiment was laid out in a randomized block design with four replicates and three crops: sweet corn (Zea mays L. cv. Applause, Brocade, and Montauk), butternut squash (Cucurbita moschata Duchesne cv. JWS 6823), and potatoes (Solanum tuberosum L. cv. Eva). Amendment with biosolids/yard waste cocompost (BS), dehydrated restaurant food waste (FW), gelatin manufacturing waste (GW), multisource compost (MS), paper fiber/chicken manure blend (PF), and yard waste compost (YW) did not have a negative impact on soil moisture, bulk density, electrical conductivity (EC), or the concentration of heavy metals in soil or plant tissue. Our results indicate potential uses for waste amendments including significantly raising soil pH (MS) and increasing soil organic matter [OM (YW and BS)]. The carbon-to-nitrogen ratio (C:N) of waste amendments was not a reliable predictor of soil inorganic N levels, and only some wastes increased potentially mineralizable nitrogen (PMN) levels relative to the control. Plots amended with BS, FW, and GW produced yields of sweet corn, butternut squash, and potatoes comparable with the control, whereas plots amended with YW, PF, and MS produced lower yields of sweet corn, squash, or both, although yields for potatoes were comparable with the control. In addition, the marketability of potatoes from PF plots was significantly better than that of the control in 2014. None of the wastes evaluated in this study had negative impacts on soil properties, some provided benefits to soil quality, and all produced comparable yields for at least one crop. Our results suggest that all six wastes have potential to be used as sources of plant nutrients.


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