scholarly journals Relationship of Soil Respiration to Crop and Landscape in the Walnut Creek Watershed

2005 ◽  
Vol 6 (6) ◽  
pp. 812-824 ◽  
Author(s):  
T. B. Parkin ◽  
T. C. Kaspar ◽  
Z. Senwo ◽  
J. H. Prueger ◽  
J. L. Hatfield
Keyword(s):  
Microbial Biomass ◽  
Soil Respiration ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Net Primary Production ◽  
Plant Root ◽  
System Effect ◽  
Organic C ◽  
Creek Watershed

Abstract Soil respiration is an important component of the carbon dynamics of terrestrial ecosystems. Many factors exert controls on soil respiration, including temperature, soil water content, organic matter, soil texture, and plant root activity. This study was conducted to quantify soil respiration in the Walnut Creek watershed in central Iowa, and to investigate the factors controlling this process. Six agricultural fields were identified for this investigation: three of the fields were cropped with soybean [Glycine max (L.) Merr.] and three were cropped with corn (Zea mays L.). Within each field, soil respiration was measured at nine locations, with each location corresponding to one of three general landscape positions (summit, side slope, and depression). Soil respiration was measured using a portable vented chamber connected to an infrared gas analyzer. Soil samples were collected at each location for the measurement of soil water content, pH, texture, microbial biomass, and respiration potential. Field respiration rates did not show a significant landscape effect. However, there was a significant crop effect, with respiration from cornfields averaging 37.5 g CO2 m−2 day−1 versus an average respiration of 13.1 g CO2 m−2 day−1 in soybean fields. In contrast, laboratory measurements of soil respiration potential, which did not include plant roots, showed a significant landscape effect and an insignificant cropping system effect. Similar relationships were observed for soil organic C and microbial biomass. Additional analyses indicate that corn roots may be more important than soybean roots in their contribution to surface CO2 flux, and that root respiration masked landscape effects on total soil respiration. Also, the failure to account for soil respiration may lead to biased estimates of net primary production measured by eddy covariance.

scholarly journals Landscape structure, groundwater dynamics, and soil water content influence soil respiration across riparian-hillslope transitions in the Tenderfoot Creek Experimental Forest, Montana

2010 ◽  
Vol 25 (5) ◽  
pp. 811-827 ◽  
Author(s):  
Vincent J. Pacific ◽  
Brian L. McGlynn ◽  
Diego A. Riveros-Iregui ◽  
Daniel L. Welsch ◽  
Howard E. Epstein
Keyword(s):  
Soil Respiration ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Landscape Structure ◽  
Groundwater Dynamics

Modelling oxygen transport in soil with plant root and microbial oxygen consumption: depth of oxygen penetration

Soil Research ◽  
2013 ◽  
Vol 51 (6) ◽  
pp. 539 ◽  
Author(s):  
F. J. Cook ◽  
J. H. Knight ◽  
F. M. Kelliher
Keyword(s):  
Diffusion Coefficient ◽  
Redox Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Oxygen Concentration ◽  
Oxygen Diffusion ◽  
Plant Root ◽  
Critical Value ◽  
Critical Values

A set of equations governing oxygen diffusion and consumption in soils has been developed to include microbial and plant-root sinks. The dependent variable is the transformed oxygen concentration, which is the difference between the gaseous concentration and a scaled value of the aqueous oxygen concentration at the root–soil interface. The results show how, as the air-filled porosity decreases, the reduced oxygen flux causes the depth of extinction to decrease. The results also show how the depth of extinction at a particular value of soil water content decreases with increasing temperature, due to increased microbial respiration. The critical value of water content at which the oxygen concentration goes to extinction at a finite depth was compared with alternative calculations with only a microbial sink. By ignoring the feedback of oxygen concentration on root uptake, the alternative calculations yielded substantially higher critical values of water content at all temperatures. Two soil oxygen diffusion coefficient functions from the literature were compared and shown to give significantly different critical values of water content for fine-textured soils, one more realistic than the other. A single relationship between the extinction depth and the ratio of the water content to the critical value was shown to apply for all temperatures and soil textures. The oxygen profiles were used along with a function relating redox potential to oxygen concentration to generate redox potential profiles. This application of the model could be useful in explaining soil biochemical processes in soils. For one such process, denitrification, the depth at which a critical oxygen concentration is reached was calculated as a function of the air-filled porosity and temperature of the soil. The implications of the critical value of soil water content in terms of water-filled pore space and matric potential are discussed in relation to the diffusion coefficient functions and recent literature.

scholarly journals PERANAN EKOLOGI DUSUNG DAN NON DUSUNG DAN KONTRIBUSINYA PADA KONSERVASI LINGKUNGAN DI DESA URENG KECAMATAN LEIHITU KABUPATEN MALUKU TENGAH

2018 ◽  
Vol 2 (1) ◽  
pp. 28-48
Author(s):  
Napsiah Heluth ◽  
J. Matinahoru ◽  
Fransina Latumahina
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Air Temperature ◽  
Organic Content ◽  
Environmental Conservation ◽  
Soil Macrofauna ◽  
Organic C

The research study aims to determine the ecological conditions of dusung and non dusung, and the role of the contribution to environmental conservation in Ureng Village. The research method used was purposive sampling with observation parameters were microclimate (CO2 content, air temperature, humidity), vegetation conditions and soil conditions (soil temperature, soil moisture, soil pH, soil moisture content, soil macrofauna and organic C) . The results of  Paired of each parameter measured mostly show a smaller calculated t value compared to the t0.05 table value (1.8595) which means that the parameter is not a real difference, ie for the air humidity, t count = 0.27,; soil pH, t count = 0.6; soil macrofauna, t count = -0.66 and vegetation, t count = 1.01. As for the parameters of CO2; air temperature, soil temperature, , soil water content and organic C, t value of CO2 gives the value t count = - 16.06; air temperature = -5.11; soil temperature = -3.62; soil moisture, t count = 2,16; soil water content = 8.47, and C-Organic = 8.53; t count value which is greater than t table value which shows that there is a significant difference between CO2, air temperature, soil temperature, soil moisture, soil water content and C-Organic content in the dusung area which is greater than in the non-dusung area. From the results of the analysis it is known that dusung has a better role in environmental conservation when compared to non dusung which is indicated by the value of CO2 air temperature, soil temperature, soil moisture, soil water content and C-organic content.

scholarly journals Nitrous oxide emissions from soil of an African rain forest in Ghana

2012 ◽  
Vol 9 (11) ◽  
pp. 16565-16588 ◽  
Author(s):  
S. Castaldi ◽  
T. Bertolini ◽  
A. Valente ◽  
T. Chiti ◽  
R. Valentini
Keyword(s):  
Soil Respiration ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Rain Forest ◽  
Nitrous Oxide Emissions ◽  
Clear Correlation ◽  
N2o Emissions ◽  
African Continent ◽  
N2o Fluxes

Abstract. Most recently atmospheric studies have evidenced the imprint of large N2O sources in tropical/subtropical lands. This source might be attributed to agricultural areas as well as to natural humid ecosystems. The uncertainty related to both sources is very high, due to the paucity of data and small frequency of sampling in tropical studies. This is particularly relevant for the African continent. The principal objective of this work was to quantify the annual budget of N2O emissions in an African tropical rain forest. Soil N2O emissions were measured over 19 months in Ghana, National Park of Ankasa, in upland and lowland areas, for a total of 119 days of observation. The calculated annual average emission was 2.33 ± 0.20 kg N-N2O ha−1yr−1, taking into account the proportion of upland vs. lowland, as the two areas showed significantly different fluxes, the lowland being characterized by lower N2O emissions. N2O fluxes peaked between June and August and were significantly correlated with soil respiration on a daily and monthly basis. No clear correlation was found in the upland areas between N2O fluxes and soil water content or rain whereas in the lowland soil water content concurred with soil respiration in determining N2O flux variability. The N2O source strength calculated in this study, very close to those reported for the other two available studies in African rain forests and to the estimated mean derived from worldwide studies in humid tropical forests (2.96 ± 2.0 kg N-N2O ha−1 yr−1), supports the concept that tropical humid forests represent the strongest natural source of N2O emissions, most probably the strongest source of N2O in the African continent.

Soil Water Content and Soil Respiration Rates Are Reduced for Years Following Wildfire in a Hot and Dry Climate

2020 ◽  
Vol 34 (12) ◽  
Author(s):  
Sol C. Cooperdock ◽  
Christine V. Hawkes ◽  
Derry R. Xu ◽  
Daniel O. Breecker
Keyword(s):  
Soil Respiration ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Respiration Rates
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