Fluxes of greenhouse gases from incubated soils using different lid-closure times

Soil Research ◽  
2018 ◽  
Vol 56 (1) ◽  
pp. 39
Author(s):  
Dang Duy Minh ◽  
Ben Macdonald ◽  
Sören Warneke ◽  
Ian White

Different sampling times for greenhouse gas measurements have been proposed in many incubation studies. Little is known about effects of closure time on denitrification and nitrification rates from incubation experiments. The objectives of this study were to analyse greenhouse gas (carbon dioxide, methane and nitrous oxide) production from different soils with different times of lid closure and to assess effects of different activation times (defined as additional pre-incubation periods before incubation experiments) on gas emissions from soils. Forty grams of air-dried soil samples (depth 0–10 cm) were incubated in 125-mL jars at 25°C with the addition of glucose and nitrate. The first experiment measured greenhouse gas fluxes at different lid-closure times (40, 80, 120 and 1440 min). The second experiment assessed the effects of different durations of soil activation (0.7, 1.3, 2 and 24 h) on gas emissions. Both were conducted with a completely randomised design, with three replicates per treatment. Our findings showed closure time <1 h or >2 h may cause an underestimate of greenhouse gas emissions. Lengthening activation times resulted in different emission rates consistent with soil characteristics. To measure gas fluxes based on linear regression would require four or five sampling points and sampling at a 20-min interval over a maximum period of 80 min for estimating gas fluxes from soil. Because pre-incubation time is critical and a driving factor in the measurement of soil-induced gas emissions, a standardised procedure to quantify gas fluxes is needed for application to other soils.

2018 ◽  
Vol 32 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Robert Czubaszek ◽  
Agnieszka Wysocka-Czubaszek

AbstractDigestate from biogas plants can play important role in agriculture by providing nutrients, improving soil structure and reducing the use of mineral fertilizers. Still, less is known about greenhouse gas emissions from soil during and after digestate application. The aim of the study was to estimate the emissions of carbon dioxide (CO2) and methane (CH4) from a field which was fertilized with digestate. The gas fluxes were measured with the eddy covariance system. Each day, the eddy covariance system was installed in various places of the field, depending on the dominant wind direction, so that each time the results were obtained from an area where the digestate was distributed. The results showed the relatively low impact of the studied gases emissions on total greenhouse gas emissions from agriculture. Maximum values of the CO2and CH4fluxes, 79.62 and 3.049 µmol s−1m−2, respectively, were observed during digestate spreading on the surface of the field. On the same day, the digestate was mixed with the topsoil layer using a disc harrow. This resulted in increased CO2emissions the following day. Intense mineralization of digestate, observed after fertilization may not give the expected effects in terms of protection and enrichment of soil organic matter.


2008 ◽  
Vol 48 (2) ◽  
pp. 244 ◽  
Author(s):  
Zoë Loh ◽  
Deli Chen ◽  
Mei Bai ◽  
Travis Naylor ◽  
David Griffith ◽  
...  

Feedlot production of beef cattle results in concentrated sources of gas emissions to the atmosphere. Reported here are the preliminary results of a micrometeorological study using open-path concentration measurements to determine whole-of-feedlot emissions of methane (CH4) and ammonia (NH3). Tunable near-infrared diode lasers were used to measure line-averaged (150–400 m) open-path concentrations of CH4 and NH3. A backward Lagrangian stochastic model of atmospheric dispersion and the software package WindTrax were used to estimate greenhouse gas fluxes from the measured concentrations. We studied typical Australian beef feedlots in the north (Queensland) and south (Victoria) of the continent. The data from a campaign during summer show a range of CH4 emissions from 146 g/animal.day in Victoria to 166 g/animal.day in Queensland and NH3 emissions from 125 g/animal.day in Victoria to 253 g/animal.day Queensland.


2016 ◽  
Vol 56 (9) ◽  
pp. 1432 ◽  
Author(s):  
J. Biala ◽  
N. Lovrick ◽  
D. Rowlings ◽  
P. Grace

Emissions from stockpiled pond sludge and yard scrapings were compared with composted dairy-manure residues blended with shredded vegetation residues and chicken litter over a 5-month period at a farm in Victoria (Australia). Results showed that methane emissions occurred primarily during the first 30–60 days of stockpiling and composting, with daily emission rates being highest for stockpiled pond sludge. Cumulated methane (CH4) emissions per tonne wet feedstock were highest for stockpiling of pond sludge (969 g CH4/t), followed by composting (682 g CH4/t) and stockpiling of yard scrapings (120 g CH4/t). Sizeable nitrous oxide (N2O) fluxes were observed only when temperatures inside the compost windrow fell below ~45−50°C. Cumulated N2O emissions were highest for composting (159 g N2O/t), followed by stockpiling of pond sludge (103 g N2O/t) and yard scrapings (45 g N2O/t). Adding chicken litter and lime to dairy-manure residues resulted in a very low carbon-to-nitrogen ratio (13 : 1) of the composting mix, and would have brought about significant N2O losses during composting. These field observations suggested that decisions at composting operations, as in many other businesses, are driven more by practical and economic considerations rather than efforts to minimise greenhouse-gas emissions. Total greenhouse-gas emissions (CH4 + N2O), expressed as CO2-e per tonne wet feedstock, were highest for composting (64.4 kg), followed by those for stockpiling of pond sludge (54.5 kg) and yard scraping (16.3 kg). This meant that emissions for composting and stockpiling of pond sludge exceeded the new Australian default emission factors for ‘waste composting’ (49 kg). This paper proposes to express greenhouse-gas emissions from secondary manure-management systems (e.g. composting) also as emissions per tonne wet feedstock, so as to align them with the approach taken for ‘waste composting’ and to facilitate the development of emission-reduction methodologies for improved manure management at the farm level.


2018 ◽  
Vol 55 (3) ◽  
pp. 395-411 ◽  
Author(s):  
WEIQI WANG ◽  
JORDI SARDANS ◽  
CHUN WANG ◽  
CHUAN TONG ◽  
QINYANG JI ◽  
...  

SUMMARYSuitable fertilization is crucial for the sustainability of rice production and for the potential mitigation of global warming. The effects of fertilization on porewater nutrients and greenhouse-gas fluxes in cropland, however, remain poorly known. We studied the effects of no fertilization (control), standard fertilization and double fertilization on the concentrations of porewater nutrients, greenhouse-gas fluxes and emissions, and rice yield in a subtropical paddy in southeastern China. Double fertilization increased dissolved NH4+ in porewater. Mean CO2 and CH4 emissions were 13.5% and 7.4%, and 20.4% and 39.5% higher for the standard and double fertilizations, respectively, than the control. N2O depositions in soils were 61% and 101% higher for the standard and double fertilizations, respectively, than the control. The total global warming potentials (GWPs) for all emissions were 14.1% and 10.8% higher for the standard and double fertilizations, respectively than the control, with increasing contribution of CH4 with fertilization and a CO2 contribution > 85%. The total GWPs per unit yield were significantly higher for the standard and double fertilizations than the control by 7.3% and 10.9%, respectively. The two levels of fertilization did not significantly increase rice yield. Prior long-term fertilization in the paddy (about 20 years with annual doses of 95 kg N ha−1, 70 kg P2O5 ha−1 and 70 kg K2O ha−1) might have prevented these fertilizations from increasing the yield. However, fertilizations increased greenhouse-gas emissions. This situation is common in paddy fields in subtropical China, suggesting a saturation of soil nutrients and the necessity to review current fertilization management. These areas likely suffer from unnecessary nutrient leaching and excessive greenhouse-gas emissions. These results provide a scientific basis for continued research to identify an easy and optimal fertilization management solution.


2016 ◽  
Vol 18 (7) ◽  
pp. 844-853 ◽  
Author(s):  
Philippe Vidon ◽  
Satish Serchan

In forest streams, riparian zone gas emissions exceed those of in-stream locations, with most CO2eq driven by CH4 production.


2021 ◽  
Author(s):  
James F. Spray ◽  
Thomas Wagner ◽  
Juliane Bischoff ◽  
Sara Trojahn ◽  
Sevda Norouzi ◽  
...  

Abstract. Connecting tropical rainforests to larger rivers, tropical headwaters export large quantities of carbon and nutrients as dissolved organic matter (DOM), and are thus a key component of the global carbon cycle. This DOM transport is not passive, however; sunlight and microbial activity alter DOM concentrations and compositions, affecting riverine greenhouse gas emissions and downstream ecosystems. The effects of sunlight and microbial turnover/activity on DOM concentrations and compositions in tropical headwaters are currently poorly understood, but novel Size Exclusion Chromatography (SEC) techniques coupled to suitable detectors can for the first time quantify their influences. Here, we present in-situ incubation experiments from from headwaters of the Essequibo River, in the Iwokrama Rainforest, Guyana, where sunlight oxidised up to 9% of dissolved organic carbon (DOC) over 12 hours, at higher rates than in larger tropical rivers. DOM transformations occurred in both photo-sensitive and supposedly photo-resistant pools. Microbial activity had varying, less clear influences on DOC concentrations over the same time span; compositionally, this appeared to extend beyond known bio-labile components. Biopolymers were particularly reactive to both processes. We show sunlight has the greater potential to mineralise headwater DOM and thus potentially influence degassing. Our approach provides a future template to constrain DOM transformations along river networks, identify biogeochemical activity hotspots, and improve greenhouse gas emissions estimations under changing environmental conditions.


Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1397
Author(s):  
Jennifer Bussell ◽  
Felicity Crotty ◽  
Chris Stoate

Soil compaction can occur due to trafficking by heavy equipment and be exacerbated by unfavourable conditions such as wet weather. Compaction can restrict crop growth and increase waterlogging, which can increase the production of the greenhouse gas nitrous oxide. Cultivation can be used to alleviate compaction, but this can have negative impacts on earthworm abundance and increase the production of the greenhouse gas carbon dioxide. In this study, a field was purposefully compacted using trafficking, then in a replicated plot experiment, ploughing, low disturbance subsoiling and the application of a mycorrhizal inoculant were compared as methods of compaction alleviation, over two years of cropping. These methods were compared in terms of bulk density, penetration resistance, crop yield, greenhouse gas emissions and earthworm abundance. Ploughing alleviated topsoil compaction, as measured by bulk density and penetrometer resistance, and increased the crop biomass in one year of the study, although no yield differences were seen. Earthworm abundance was reduced in both years in the cultivated plots, and carbon dioxide flux increased significantly, although this was not significant in summer months. Outside of the summer months, nitrous oxide production increased in the non-cultivated treatments, which was attributed to increased denitrifying activity under compacted conditions.


2013 ◽  
Vol 10 (5) ◽  
pp. 3185-3203 ◽  
Author(s):  
L. Merbold ◽  
C. Steinlin ◽  
F. Hagedorn

Abstract. Although greenhouse gas emissions during winter contribute significantly to annual balances, their quantification is still highly uncertain in snow-covered ecosystems. Here, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes were measured at a subalpine managed grassland in Switzerland using concentration gradients within the snowpack (CO2, CH4, N2O) and the eddy covariance method (CO2) during the winter 2010/2011. Our objectives were (1) to identify the temporal and spatial variation of greenhouse gases (GHGs) and their drivers, and (2) to estimate the GHG budget of the site during this specific season (1 December–31 March, 121 days). Mean winter fluxes (December–March) based on the gradient method were 0.77 ± 0.54 μmol m−2 s−1 for CO2 (1.19 ± 1.05 μmol m−2 s−1 measured by eddy covariance), −0.14 ± 0.09 nmol m−2 s−1 for CH4 and 0.23 ± 0.23 nmol m−2 s−1 for N2O, respectively. In comparison with the CO2 fluxes measured by eddy covariance, the gradient technique underestimated the effluxes by 50%. While CO2 and CH4 fluxes decreased with the progressing winter season, N2O fluxes did not follow a seasonal pattern. The major variables correlating with the fluxes of CO2 and CH4 were soil temperature and snow water equivalent, which is based on snow height and snow density. N2O fluxes were only explained poorly by any of the measured environmental variables. Spatial variability across the valley floor was smallest for CO2 and largest for N2O. During the winter season 2010/2011, greenhouse gas fluxes ranged between 550 ± 540 g CO2 m−2 estimated by the eddy covariance approach and 543 ± 247 g CO2 m−2, −0.4 ± 0.01 g CH4 m−2 and 0.11 ± 0.1 g N2O m−2 derived by the gradient technique. Total seasonal greenhouse gas emissions from the grassland were between 574 ± 276 and 581 ± 569 g CO2 eq. m−2, with N2O contributing 5% to the overall budget and CH4 reducing the budget by 0.1%. Cumulative budgets of CO2 were smaller than emissions reported for other subalpine meadows in the Swiss Alps and the Rocky Mountains. Further investigations on the GHG exchange of grasslands in winter are needed in order to (1) deepen our currently limited knowledge on the environmental drivers of each GHG, (2) to thoroughly constrain annual balances, and (3) to project possible changes in GHG flux magnitude with expected shorter and warmer winter periods.


2021 ◽  
Author(s):  
Peter Levy ◽  
Robert Jon Clement ◽  
Nicholas Jon Cowan ◽  
Ben Keane ◽  
Vasileios Myrgiotis ◽  
...  

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