Novel Chamber to Measure Equilibrium Soil–Air Partitioning Coefficients of Low-Volatility Organic Chemicals under Conditions of Varying Temperature and Soil Moisture

2008 ◽  
Vol 42 (13) ◽  
pp. 4870-4876 ◽  
Author(s):  
André Wolters ◽  
Volker Linnemann ◽  
Kilian E. C. Smith ◽  
Eva Klingelmann ◽  
Byung-Jun Park ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Organic Chemicals ◽  
Soil Air ◽  
Partitioning Coefficients

Transport and transformations of organic chemicals in the soil-air-water ecosystem

1987 ◽  
pp. 119-164 ◽  
Author(s):  
William A. Jury ◽  
Arthur M. Winer ◽  
William F. Spencer ◽  
Dennis D. Focht
Keyword(s):  
Organic Chemicals ◽  
Soil Air ◽  
Water Ecosystem

scholarly journals Soil methane oxidation in both dry and wet temperate eucalypt forests shows a near-identical relationship with soil air-filled porosity

2017 ◽  
Vol 14 (2) ◽  
pp. 467-479 ◽  
Author(s):  
Benedikt J. Fest ◽  
Nina Hinko-Najera ◽  
Tim Wardlaw ◽  
David W. T. Griffith ◽  
Stephen J. Livesley ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Climate Change Scenarios ◽  
Soil Air ◽  
Eucalypt Forest ◽  
Soil Atmosphere ◽  
Forest Sites ◽  
Ch4 Uptake ◽  
Eucalypt Forests ◽  
The Impact

Abstract. Well-drained, aerated soils are important sinks for atmospheric methane (CH4) via the process of CH4 oxidation by methane-oxidising bacteria (MOB). This terrestrial CH4 sink may contribute towards climate change mitigation, but the impact of changing soil moisture and temperature regimes on CH4 uptake is not well understood in all ecosystems. Soils in temperate forest ecosystems are the greatest terrestrial CH4 sink globally. Under predicted climate change scenarios, temperate eucalypt forests in south-eastern Australia are predicted to experience rapid and extreme changes in rainfall patterns, temperatures and wild fires. To investigate the influence of environmental drivers on seasonal and inter-annual variation of soil–atmosphere CH4 exchange, we measured soil–atmosphere CH4 exchange at high-temporal resolution (<  2 h) in a dry temperate eucalypt forest in Victoria (Wombat State Forest, precipitation 870 mm yr−1) and in a wet temperature eucalypt forest in Tasmania (Warra Long-Term Ecological Research site, 1700 mm yr−1). Both forest soil systems were continuous CH4 sinks of −1.79 kg CH4 ha−1 yr−1 in Victoria and −3.83 kg CH4 ha−1 yr−1 in Tasmania. Soil CH4 uptake showed substantial temporal variation and was strongly controlled by soil moisture at both forest sites. Soil CH4 uptake increased when soil moisture decreased and this relationship explained up to 90 % of the temporal variability. Furthermore, the relationship between soil moisture and soil CH4 flux was near-identical at both forest sites when soil moisture was expressed as soil air-filled porosity (AFP). Soil temperature only had a minor influence on soil CH4 uptake. Soil nitrogen concentrations were generally low and fluctuations in nitrogen availability did not influence soil CH4 uptake at either forest site. Our data suggest that soil MOB activity in the two forests was similar and that differences in soil CH4 exchange between the two forests were related to differences in soil moisture and thereby soil gas diffusivity. The differences between forest sites and the variation in soil CH4 exchange over time could be explained by soil AFP as an indicator of soil moisture status.

Nitrogenous gas production in the soil air as affected by different N fertiliser forms and water supplies in model experiments

2002 ◽  
Vol 50 (4) ◽  
pp. 433-440 ◽  
Author(s):  
K. Debreczeni ◽  
K. Berecz ◽  
K. Fischl ◽  
Z. Wittmann
Keyword(s):  
Soil Moisture ◽  
Crop Residues ◽  
Soil Depth ◽  
Gas Production ◽  
Water Supplies ◽  
Maize Crop ◽  
Soil Air ◽  
Model Experiments ◽  
Rooting Zone ◽  
Test Plants

large-pot model experiments were conducted with maize under greenhouse conditions with the aim of studying the effect of different N fertiliser forms, water supplies and crop residues on the nitrogenous gas production in the rooting zone. Nitrogen fertiliser was applied in the form of KNO3 or NH4Cl. The experiment was done at two soil moisture levels, with or without the incorporation of maize crop residues into the soil, and with or without test plants. Gas traps were placed in the pots at a soil depth of 20 cm. During the growing season, the trapped soil air was analysed for NOx, N2O and N2. Practically the same N amounts evolved in the soil air with both chemical forms of N fertiliser at both soil moisture levels. expressed as a percentage of fertiliser N, the total amount of gaseous N evolved averaged 12.8% and 12.9% in the planted, and 23.8% and 24.3% in the unplanted pots with KNO3 and NH4Cl fertiliser, respectively. Higher soil moisture and the incorporation of crop residues resulted in higher NOx-N and N2O-N ratios within the total gaseous N evolved in the rooting zone.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

PROTOTIPE APLIKASI PENYIRAMAN TANAMAN MENGGUNAKAN SENSOR KELEMBABAN TANAH BERBASIS MICRO CONTOLLER ATMEGA 328

2019 ◽  
Vol 5 (1) ◽  
pp. 97-106
Author(s):  
Rudi Budi Agung ◽  
Muhammad Nur ◽  
Didi Sukayadi
Keyword(s):  
Soil Moisture ◽  
Growth And Development ◽  
Large Scale ◽  
Simple Method ◽  
Moisture Sensor ◽  
Sensor Development ◽  
Soil Moisture Sensor ◽  
Application Systems ◽  
Harvesting Systems ◽  
Working Principle

The Indonesian country which is famous for its tropical climate has now experienced a shift in two seasons (dry season and rainy season). This has an impact on cropping and harvesting systems among farmers. In large scale this is very influential considering that farmers in Indonesia are stilldependent on rainfall which results in soil moisture. Some types of plants that are very dependent on soil moisture will greatly require rainfall or water for growth and development. Through this research, researchers tried to make a prototype application for watering plants using ATMEGA328 microcontroller based soil moisture sensor. Development of application systems using the prototype method as a simple method which is the first step and can be developed again for large scale. The working principle of this prototype is simply that when soil moisture reaches a certainthreshold (above 56%) then the system will work by activating the watering system, if it is below 56% the system does not work or in other words soil moisture is considered sufficient for certain plant needs.

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