1) The study assessed the relationship between soil moisture held at different water potentials (matric potentials) and greenhouse gas fluxes in a corn-soybean field.
2) Soil samples were collected and analyzed at various matric potentials (0, -0.05, -0.1, -0.33, and -15 bars) to determine soil moisture levels. Higher moisture levels were found at 0 and -0.05 bars.
3) When soil moisture was near saturated conditions (0 bar matric potential), CO2 and N2O fluxes were positively correlated with soil moisture levels, while CH4 fluxes were negatively correlated.
Objectives:
- Determine how soil moisture and nutrients regulate microbial C-use efficiency (CUE)
- Develop mathematical functions that can be incorporated into earth system models
- Improve our ability to predict the impact of climate change on soil C-sequestration in agricultural systems
Objectives:
- Determine how soil moisture and nutrients regulate microbial C-use efficiency (CUE)
- Develop mathematical functions that can be incorporated into earth system models
- Improve our ability to predict the impact of climate change on soil C-sequestration in agricultural systems
Effect of Air Relative Humidity Harvest on Soil Moisture Content under Morocc...IJERA Editor
In this work, we aim to analyse the effect of the harvest of air relative humidity on soil water content. Some experiments were conducted on hilly areas with various hypsographic and microclimatic conditions greatly affecting daily fluctuations of air relative humidity. The metrological data’s were obtained by using a Campbell Scientific equipments station recorder on data loggers every half hour. Time Domain Reflectometers (TDR) is used for calculating water content at different soil layers. The effect of many parameters such as: minimal and maximal air atmospheric humidity, potential of soil water and minimal temperature of air on harvesting air relative humidity is also discussed. The experimental results indicate that soil moisture content in the upper soil layer fluctuates with the same manner to diurnal fluctuation of relative air humidity. These fluctuations due to the harvest of relative air humidity decreased with increasing soil depth and daily amplitude of relative air humidity. The water adsorbed according to this phenomenon increased with increasing maximal relative and decreasing minimal temperature. The contribution of this soil water collected is about 40% of losses due to evaporation process. The correlation between principal climatic data and soil water adsorption by harvest relative air humidity is presented in this paper in order to incorporate it in the total water balance during water infiltration.
Effects of a raised water table on greenhouse gas emissions and celery yield ...ExternalEvents
This presentation was presented during the 2 Parallel session on Theme 3.1, Managing SOC in: Soils with high SOC – peatlands, permafrost, and black soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Ms. Magdalena J. Matysek, from University of Sheffield - UK, in FAO Hq, Rome
River ice jams : risk evaluation, driving conditions and geomorphological imp...etbou24
This ppt describes my scientific activities over the last few years. It is of interest for scientists and engineers how want to know more about long-term ice jams dynamics and physical impacts. Please contact me for more info:
boucher@cerege.fr
07 lutes slides for epa 2018 workshop moisturev5Chris Lutes
Lutes, C. “Indicators, Tracers, and Surrogates of Chlorinated Vapor Intrusion – Potential for
Rain, Soil Moisture, Water Table, Snow and Ice” oral presentation at EPA Workshop at 28th Annual AEHS International West Coast Conference on Soils, Water, Energy and Air, March 20, 2018.
Trace gas batch inverse problems are often formulated in a Bayesian framework that require minimization of an objective function that takes as an input atmospheric measurements of trace gas concentrations, prior estimates of fluxes, and a transport operator that describes the influence of the sources of fluxes on measurements. As part of minimization, batch inverse problems require computation of covariance matrices that describes the error in measurements and prior fluxes. Most of the computational/data bottlenecks in these inverse problems occur in estimating the transport operator that require processing of terabytes of output generated from a Weather model. Typically, this output is stored on tape storage system that needs to copied or moved into an intermediary storage system for computing the transport operator and finally the covariance matrices that are used in inverse problems. This operation of bringing data to the algorithm is an inefficient and time-delaying way to solve these problems and therefore necessitates development of methods that can work on partitioned observations and transport operator and compute covariance matrices and inverse estimates of fluxes at locations of data storage.
Peatland hydrological drought and fire risk assessment in changing climateCIFOR-ICRAF
Presented by Muh. Taufik, lecturer of Department of Geophysics and Meteorology, IPB University, Bogor, Indonesia, at "Online Webinar 2: Biophysical Attributes and Peatland Fires", on 14 October 2020
This speaker shared information about research on the assessment of the hydrological condition and fire risk in degraded peatland and restored peatland. This presentation also showed the importance of peatland rewetting and elevating groundwater table in reducing fire hazards in tropical peatlands.
Monitoring tropical peatlands GHG emissions: Is current scientific knowledge ...CIFOR-ICRAF
Presented by Kristell Hergoualc’h, Senior Scientist, CIFOR, at "Online Webinar 2: Biophysical Attributes and Peatland Fires", on 14 October 2020
This presentation underlined existing gaps in data and knowledge on GHG emissions accounting for tropical peatland after restoration efforts. She also shared insights about how GHG emissions can arise from a range of human activities and microbial activities.
This presentation by Mason Johnson, a master's student at the University of Nebraska-Lincoln, was presented at the Daugherty Water for Food Global Institute’s Research Forum on Thursday, May 11, 2017. Mason is a 2016-2017 student support grantee of the Institute.
Effect of Air Relative Humidity Harvest on Soil Moisture Content under Morocc...IJERA Editor
In this work, we aim to analyse the effect of the harvest of air relative humidity on soil water content. Some experiments were conducted on hilly areas with various hypsographic and microclimatic conditions greatly affecting daily fluctuations of air relative humidity. The metrological data’s were obtained by using a Campbell Scientific equipments station recorder on data loggers every half hour. Time Domain Reflectometers (TDR) is used for calculating water content at different soil layers. The effect of many parameters such as: minimal and maximal air atmospheric humidity, potential of soil water and minimal temperature of air on harvesting air relative humidity is also discussed. The experimental results indicate that soil moisture content in the upper soil layer fluctuates with the same manner to diurnal fluctuation of relative air humidity. These fluctuations due to the harvest of relative air humidity decreased with increasing soil depth and daily amplitude of relative air humidity. The water adsorbed according to this phenomenon increased with increasing maximal relative and decreasing minimal temperature. The contribution of this soil water collected is about 40% of losses due to evaporation process. The correlation between principal climatic data and soil water adsorption by harvest relative air humidity is presented in this paper in order to incorporate it in the total water balance during water infiltration.
Effects of a raised water table on greenhouse gas emissions and celery yield ...ExternalEvents
This presentation was presented during the 2 Parallel session on Theme 3.1, Managing SOC in: Soils with high SOC – peatlands, permafrost, and black soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Ms. Magdalena J. Matysek, from University of Sheffield - UK, in FAO Hq, Rome
River ice jams : risk evaluation, driving conditions and geomorphological imp...etbou24
This ppt describes my scientific activities over the last few years. It is of interest for scientists and engineers how want to know more about long-term ice jams dynamics and physical impacts. Please contact me for more info:
boucher@cerege.fr
07 lutes slides for epa 2018 workshop moisturev5Chris Lutes
Lutes, C. “Indicators, Tracers, and Surrogates of Chlorinated Vapor Intrusion – Potential for
Rain, Soil Moisture, Water Table, Snow and Ice” oral presentation at EPA Workshop at 28th Annual AEHS International West Coast Conference on Soils, Water, Energy and Air, March 20, 2018.
Trace gas batch inverse problems are often formulated in a Bayesian framework that require minimization of an objective function that takes as an input atmospheric measurements of trace gas concentrations, prior estimates of fluxes, and a transport operator that describes the influence of the sources of fluxes on measurements. As part of minimization, batch inverse problems require computation of covariance matrices that describes the error in measurements and prior fluxes. Most of the computational/data bottlenecks in these inverse problems occur in estimating the transport operator that require processing of terabytes of output generated from a Weather model. Typically, this output is stored on tape storage system that needs to copied or moved into an intermediary storage system for computing the transport operator and finally the covariance matrices that are used in inverse problems. This operation of bringing data to the algorithm is an inefficient and time-delaying way to solve these problems and therefore necessitates development of methods that can work on partitioned observations and transport operator and compute covariance matrices and inverse estimates of fluxes at locations of data storage.
Peatland hydrological drought and fire risk assessment in changing climateCIFOR-ICRAF
Presented by Muh. Taufik, lecturer of Department of Geophysics and Meteorology, IPB University, Bogor, Indonesia, at "Online Webinar 2: Biophysical Attributes and Peatland Fires", on 14 October 2020
This speaker shared information about research on the assessment of the hydrological condition and fire risk in degraded peatland and restored peatland. This presentation also showed the importance of peatland rewetting and elevating groundwater table in reducing fire hazards in tropical peatlands.
Monitoring tropical peatlands GHG emissions: Is current scientific knowledge ...CIFOR-ICRAF
Presented by Kristell Hergoualc’h, Senior Scientist, CIFOR, at "Online Webinar 2: Biophysical Attributes and Peatland Fires", on 14 October 2020
This presentation underlined existing gaps in data and knowledge on GHG emissions accounting for tropical peatland after restoration efforts. She also shared insights about how GHG emissions can arise from a range of human activities and microbial activities.
This presentation by Mason Johnson, a master's student at the University of Nebraska-Lincoln, was presented at the Daugherty Water for Food Global Institute’s Research Forum on Thursday, May 11, 2017. Mason is a 2016-2017 student support grantee of the Institute.
Measurement of soil carbon is the focus of attention of present and future international conventions and agreements, related to global climate change. Past inventories and current carbon stock inventories involve different analytical methods, and methodological biases and uncertainties should be reduced to develop reliable estimates of the effects of land uses changes on total organic carbon. Furthermore, the carbon-equivalent is highly variable, and there is the need of using a specific correction factor for each location, resulting from the combination of land use, textural gradients, and sampling depth. In this context, the aims of this study were creating correction equations for the determinations through wet combustion (Walkley-Black- WB) for a Rhodic Hapludox based on the determinations made through dry combustion (CS) at different depths and management systems. The experimental design was 4 x 5 factorial with 3 replications. Treatments were: Conventional Tillage (CT); Minimum Tillage (MT); No-till with chisel plowing (NTC) and No-Till (NT). The collection depths were: 0-2.5; 2.5-5; 5-10; 10-20 and 20-40 cm. The measured carbon equivalent values ranged from 1.06 to 1.18 and were dependent on land use and soil depth. Rhodic Hapludox under different management presented the following order of carbon equivalent values: NTC < CT < NT < MT. The carbon equivalent values increased with depth. The high ratio between C-WB and C-CS (R2= 0.75, p= 0.0001) justifies the use of correction factors.
Distribution and mobility of lead and zinc atmospheric depositions in industr...INFOGAIN PUBLICATION
Heavy metal contamination is a severe environmental problem. Knowledge of the total heavy metals contents of soils is a necessary step for making an accurate appraisal and quantitative evaluation of the extent of contamination, indeed, wet and dry atmospheric deposits, plays an important role in the cycle of semi-volatile contaminants [1]. Metallurgical industries release heavy metals into the atmosphere, these last, clump together to form fines particles suspended in the air, these metals can be transported by wind via aerosol or aqueous pathway and deposited in the soil. The main aim of this work was to study the mobility and fate of lead and zinc from atmospheric deposits in contaminated soil from the foundry (ALFET) in industrial zone of Tiaret (Western Algeria) and to determine the effect of physicochemical parameters of the soil on their mobility in the topsoil. Physicochemical analysis of 35 soil samples have shown that zinc and lead levels contents in the surface layer soil (0-30 cm) vary depending on the pH, total limestone (CaCO3) and the soil water content. Results clearly show that soil texture and fine fraction (clay and sand) significantly influence mobility of Pb and Zn in soil.
The Climate Food and Farming (CLIFF) Research Network is an international research network that helps to expand young researchers' knowledge and experience working on climate change mitigation in smallholder farming. CLIFF provides grants for selected doctoral students to work with CGIAR researchers affiliated with the Standard Assessment of Mitigation Potential and Livelihoods in Smallholder Systems (SAMPLES) project.
This presentation is Drainage of Flooded Rice Soil Influence the Residue Carbon Contribution in Methane Emissions by Phan Hữu Thành, at the Institute for Agricultural Environment, Vietnamese Academy of Agriculture Sciences, in Hanoi, Vietnam.
Drought Vulnerability Modeling for Georgia - Rebecca PeoplesRebecca Evans
For my final presentation in my Hydrology class, I created a Drought Vulnerability Model for the state of Georgia. In measuring the potential for drought, we can have actionable prevention and responsible water usage changes. Taking into factor, precipitation, temperature, crop water consumption, ground water wells, land use, slope, soil type and geology of Georgia, we can effectively model potential areas in Georgia that would be vulnerable for drought.
Re-wetting drained peatlands can reduce large greenhouse gas emissionsExternalEvents
This presentation was presented during the 2 Parallel session on Theme 3.1, Managing SOC in: Soils with high SOC – peatlands, permafrost, and black soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. He Hongxing, from University of Gothenburg - Sweden, in FAO Hq, Rome
Re-wetting drained peatlands can reduce large greenhouse gas emissionsStankovic G
This presentation was presented during the 2 Parallel session on Theme 3.1, Managing SOC in: Soils with high SOC – peatlands, permafrost, and black soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. He Hongxing, from University of Gothenburg - Sweden, in FAO Hq, Rome
1. This research is part of a regional collaborative project supported by the USDA-NIFA, Award No. 2011-68002-30190:
Cropping Systems Coordinated Agricultural Project: Climate Change, Mitigation, and Adaptation in Corn-based Cropping Systems
Project Web site: sustainablecorn.org
Soil Water Potential Control of the Relationship
between Moisture and Greenhouse Gases Fluxes in
Corn-Soybean Field
Dinesh Panday* and Nsalambi V. Nkongolo
Department of Agriculture and Environmental Sciences, Lincoln University, MO
2. Introduction
• Agriculture is a significant source of three main biogenic GHGs
(CO2, N2O and CH4) fluxes and the ways of management of soils,
it can constitute as either a net source or sink of these GHGs.
• Greenhouse gases produced in soils move through the exchange
of gas between the soil surface and the adjacent atmosphere.
This exchange can occur by means of two mechanisms:
diffusion and advection and it is done through the pore space.
• Both temperature and moisture are important controls on
decomposition processes for GHGs but is more strongly related
to soil water content (Conrad, 1989).
3. • The water status in soils is characterized by the amount of
water present, called as soil water content (SWC, θ) and its
energy state, called as soil water potential (SWP, Ψ).
• SWC is expressed on a gravimetric or volumetric basis and
represented by percent whereas SWP measurement is pressure
(Pa or bar) usually the expressed as a negative number.
• The term “suction” and “tension” are definitions developed to
avoid using the negative sign and to represent the SWP as
positive numbers.
4. • Several authors have studied the relationship between SWC and
GHGs fluxes and most of them have quantified SWC but the
energy state of that water or the potential at which this soil
water was held was not measured.
• Tremendous efforts are devoted to understanding the
relationship between GHGs and soil controlling factors such as
soil moisture on daily, weekly, bi-weekly and monthly basic.
• However, to save energy, time and financial resources it would
have been better if such measurements could have been done
only when soil moisture was held at certain water potentials.
5. Objectives
To assess the relationship between soil moisture (θ) held at
different water potentials () and GHGs fluxes in corn-soybean
rotational field.
6. Methodology
• The experiment was conducted on silt loam soil at the Freeman
farm of the Lincoln University of Missouri in 2011.
• Total of 48 plots with 12.19 m width by 21.34 m length for each,
3 factorial experiment in a RCBD with 16 treatment
combinations and 3 replications.
• The 3 factors were (i) Tillage at 2 levels (No-Tillage vs
Conventional Tillage), (ii) Cover crop at 2 levels (Rye vs No-Rye)
and (iii) Cropping sequence or rotation at four levels
(Continuous Corn, Continuous Soybean, Corn-Soybean and
Soybean-Corn rotations).
7. Soil and Soil Air Sampling
• Soil samples were collected at four depths: 0-10, 10-20, 20-40
and 40-60 cm, then air-filled porosity (AFP) and other soil
properties were calculated.
• Soil air samples for gas analysis were collected using 48
individual PVC static and vented chambers (30 cm Ht * 20 cm
Dia) in each plot. Concentrations of CO2, N2O and CH4 from soil
air samples were measured with a Shimadzu GC-2014 gas
chromatograph.
8. Soil Moisture Measurement
• Soil samples were placed onto a ceramic porous plate and
wetted for overnight, the pressure chambers were closed and a
specified pressure was applied by an air compressor.
• The sample started losing water that moved through the porous
plate. After the water ceased to drain, the samples were
collected at the specified pressure (SWP, = 0, -0.05, -0.1, -0.33
and -15 bar).
• The soil sample was then removed from the plate, weighted and
placed into an oven, for gravimetric determination of soil water
content.
9. Result and Discussions
Summary statistics for soil moisture at different matric potentials
Statistics m =0 m =-0.05 m =-0.1 m =-0.33 m =-15
Mean 0.33 0.21 0.13 0.12 0.09
SD 0.07 0.04 0.01 0.01 0.02
C.V. 21.86 21.61 9.25 8.61 18.47
Minimum 0.18 0.11 0.10 0.09 0.06
Median 0.34 0.21 0.13 0.12 0.09
Maximum 0.45 0.31 0.16 0.14 0.12
Skew -0.33 -0.12 -0.09 0.39 0.07
Kurtosis -1.09 0.71 -0.39 0.30 -1.40
Considerable differences were found in the mean soil moisture contents across the potential at
0 and -0.05 bar where moisture level was 33 and 21 percent respectively.
10. Statistics CO2 (mg m−2 h−1 ) N2O (μg m−2 h−1 ) CH4 (μg m−2 h−1 )
Mean 477.83 21.02 16.82
SD
125.67 100.87 292.21
C.V. 26.30 479.85 1737.10
Minimum 318.05 -108.49 -315.27
Median 462.37 -15.65 -110.04
Maximum 764.78 285.82 751.47
Skew 0.94 1.04 1.07
Kurtosis 0.03 0.45 0.20
Summary statistics for soil moisture at different matric potentials
11. y = 1535.4x - 277.91
R² = 0.4096
-50
0
50
100
150
200
250
300
350
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Nitrousoxide(μgm−2h−1)
Soil moisture at 0 matric potential
Fig.3. Relationship between m = 0 and N2O emissions
Relation between soil moisture (at m =0) and GHGs fluxes
12. Summary
When soil matric potential (m) was close to 0 bar i.e., saturated
conditions at 0-10 cm depth, soil moisture was positively
correlated with CO2 and N2O fluxes with correlation coefficients
ranging from 0.49 to 0.64, but negatively correlation with CH4 (-
0.43) fluxes at p<0.05.
13. Conclusions
We conclude that when soil water was held at matric potentials
close to zero, there were higher CO2 and N2O emissions and higher
CH4 uptake in 0–10 cm soil depth.
Since soil moisture availability is controlled by the matric potential
at which this water is held, this study stresses the need to monitor
soil water potential when monitoring greenhouse gases fluxes.