scholarly journals Application of the Denitrification-Decomposition Model to Predict Carbon Dioxide Emissions under Alternative Straw Retention Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Can Chen ◽  
Deli Chen ◽  
Jianjun Pan ◽  
Shu Kee Lam
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Agricultural Soils ◽  
Pore Space ◽  
Correlation Coefficients ◽  
Growth Period ◽  
Dndc Model ◽  
Mean Temperature ◽  
Straw Retention ◽  
Straw Incorporation

Straw retention has been shown to reduce carbon dioxide (CO2) emission from agricultural soils. But it remains a big challenge for models to effectively predict CO2emission fluxes under different straw retention methods. We used maize season data in the Griffith region, Australia, to test whether the denitrification-decomposition (DNDC) model could simulate annual CO2emission. We also identified driving factors of CO2emission by correlation analysis and path analysis. We show that the DNDC model was able to simulate CO2emission under alternative straw retention scenarios. The correlation coefficients between simulated and observed daily values for treatments of straw burn and straw incorporation were 0.74 and 0.82, respectively, in the straw retention period and 0.72 and 0.83, respectively, in the crop growth period. The results also show that simulated values of annual CO2emission for straw burn and straw incorporation were 3.45 t C ha−1 y−1and 2.13 t C ha−1 y−1, respectively. In addition the DNDC model was found to be more suitable in simulating CO2mission fluxes under straw incorporation. Finally the standard multiple regression describing the relationship between CO2emissions and factors found that soil mean temperature (SMT), daily mean temperature (Tmean), and water-filled pore space (WFPS) were significant.

scholarly journals Biological activity in the forest floor of artificial forests in the steppe zone

2015 ◽  
Vol 16 (3-4) ◽  
pp. 31-38
Author(s):  
Ye. I. Maltsev
Keyword(s):  
Carbon Dioxide ◽  
Enzyme Activity ◽  
Biological Activity ◽  
Catalase Activity ◽  
Carbon Dioxide Emissions ◽  
Forest Floor ◽  
Correlation Coefficients ◽  
Steppe Zone ◽  
Forest Plantations ◽  
Special Role

A special role in the biological cycle in forest biogeocoenoses plays forest floor, which connects the abiotic and biotic components in an integral system, affects the genesis of forest soils and productivity of forest plantations. The most informative indicators of biological activity of the soil and the forest floor are the activity of enzymes, the intensity of carbon dioxide emissions, the number and qualitative composition of the main groups of microorganisms. Particular specificity of these indicators acquire in artificial forest plantations in the steppe zone, due to the geographical, ecological and often a mismatch in habitat conditions for forest. The aim of this work was to study the biological activity of the forest floor in artificial forest plantations in the steppe zone of Ukraine (on the example of Staro-Berdyansk forest). Staro-Berdyansk forest (Zaporizhia region, Ukraine), founded in 1846 on the left bank of the Molochnaya river. Studies of the biological activity the forest floor carried out on stationary plots in stands of Quercus robur L., Robinia pseudoacacia L. and Pinus pallasiana D. Don during 2013 year seasonally. Analysis of the data series using correlation method showed that the increase in the forest floor the magnitude of algae, micromycete and oligotrophic microorganisms is accompanied by an increase in catalase activity (correlation coefficients: 0,80; 0,91; 0,95), at the same time micromycete and oligotrophs positively associated with thermolabile component of catalase activity (correlation coefficients: 0,75; 0,95). In periods of reduction of catalase activity increases the number of actinomycetes (r = -0,67). Polyphenol oxidase activity is positively correlated with the magnitude of micromycete in the forest floor (r = +0,68) and negatively with the population of actinomycetes (r = -0,86) and bacteria, that use mineral nitrogen compounds (r = -0,69). In periods of activation of phosphatase the magnitude of algae and micromycete decreases (r = -0,92 and r = -0,80; respectively) and cellulolytic microorganisms increases (r = +0,75). Integral indicator of biological activity of the forest floor is the amount of carbon dioxide emitted, indicating the intensity of the processes of transformation of organic matter. The greatest intensity of carbon dioxide emissions recorded in autumn samples of locust bean and pine plantations. The oak stands a high level of carbon dioxide emissions occur in summer and autumn. The magnitude of microorganisms and algae, enzyme activity and the intensity of carbon dioxide emissions in the forest floor changed by seasonal, which corresponds to the dynamics of the overall progress of biological processes occurring in the forest floor. On the biological activity of the forest floor is significantly affected by the composition of plant residues, which generally corresponds to the views of various researchers who have noted a correlation of enzyme activity in the soil with the magnitude of microorganisms, as well as biochemical and chemical composition of forest floor and the stages of its destruction.

Field-scale verification of nitrous oxide emission reduction with DCD in dairy-grazed pasture using measurements and modelling

Soil Research ◽  
2011 ◽  
Vol 49 (8) ◽  
pp. 696 ◽  
Author(s):  
Donna L. Giltrap ◽  
Surinder Saggar ◽  
Jagrati Singh ◽  
Mike Harvey ◽  
Andrew McMillan ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Agricultural Soils ◽  
Sampling Error ◽  
Pore Space ◽  
Clay Content ◽  
Field Capacity ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
Dndc Model ◽  
Input Parameters

Nitrous oxide (N2O) from agricultural soils is a major source of greenhouse gas emissions in New Zealand. Nitrification inhibitors are seen as a potential technology to reduce these N2O emissions from agricultural soils. In previous studies on the effect of dicyandiamide (DCD) on N2O emissions from animal excreta, DCD was directly applied to urine. However, farmers apply DCD to grazed pastures shortly before or after grazing rather than applying it specifically to the urine patches. Accordingly, the objectives of this study were: (1) to test, using chamber measurements, whether the same level of N2O reduction is achieved under grazed conditions where excretal N is non-uniformly deposited, (2) to apply the process-based NZ-DNDC model to simulate the effect of DCD on emission reductions, and (3) to perform a sensitivity analysis on the NZ-DNDC model to investigate how uncertainties in the input parameters affect the modelled N2O emissions. Two circular 1260-m2 treatment plots were grazed simultaneously for 5 h, by 20 cattle on each plot. The following day, DCD was applied in 800 L of water to one of the plots at 10 kg/ha and N2O emissions were measured periodically for 20 days. The cumulative N2O emissions were 220 ± 90 and 110 ± 20 g N2O-N/ha for the untreated and DCD-treated plots, respectively (based on the arithmetic mean and standard error of the chambers). This suggests a reduction in N2O emission from DCD application of ~50 ± 40% from a single grazing event. However, this result should be treated with caution because the possibility of sampling error due to the chamber distribution cannot be excluded. NZ-DNDC simulated N2O emissions of 169 and 68 g N2O-N/ha for the untreated and DCD-treated areas, respectively, corresponding to a reduction of 60% in N2O emissions from DCD application. This level of reduction is consistent with that found in experiments with individual urine patches. N2O emissions found through use of NZ-DNDC were sensitive to uncertainties in the input parameters. The combined effect of varying the initial soil NO3– and NH4+, soil moisture, soil organic carbon, bulk density, clay content, pH, and water-filled pore-space at field capacity inputs within plausible ranges was to change the simulated N2O emissions by –87% to +150%.

scholarly journals Emission of Carbon Dioxide from the Dark Chestnut Soil in West Kazakhstan

2019 ◽  
Vol 9 (1) ◽  
pp. 6676-6680
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Agricultural Soils ◽  
Humus Content ◽  
Chestnut Soil ◽  
Anthropogenic Factors ◽  
Dark Chestnut Soil ◽  
Negative Effect ◽  
West Kazakhstan ◽  
Active Release

The necessity of studying and assessing emissions of carbon dioxide from the agricultural soils is related to the important role played by the soil in their formation. Active release of carbon dioxide shows changes in the content of the organic matter in the soil and its biological activity. Carbon dioxide emissions can be influenced both by biotic and anthropogenic factors. Due to the negative effect of grazing and arable plots on the soil respiration, unequal emission of carbon dioxide is noted. The research was aimed at assessing the dynamics of carbon dioxide emissions from the dark-chestnut soil, depending on the nature of the soil use in agriculture. The studies for determining the carbon dioxide flow rate were performed according to the standard variant of the closed dynamic chamber method. The results of studying the content and emission of carbon dioxide from the dark-chestnut soil of the agricultural lands in Western Kazakhstan are shown. The content and reserves of humus in the 100 cm layer of the studied soils are low, and the soil is characterized by low humus content. The total annual flow of carbon dioxide from the virgin lands is higher than that from the arable lands but is less than that from the pastures

Energy Use and Carbon Dioxide Emissions from Cropland Production in the United States, 1990-2004

2008 ◽  
Author(s):  
R.G. Nelson, ◽  
C.H. Hellwinckel, ◽  
C.C. Brandt, ◽  
T.O. West, ◽  
D.G. De La Torre Ugarte, ◽  
...  
Keyword(s):  
United States ◽  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Energy Use ◽  
The United States
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