Systematic exploration of near‐surface soil dynamics: Determining resonant or preferred frequencies in three soil types by isolating and changing mechanical wave properties associated with frequency, amplitude, and load time

2007 ◽  
Author(s):  
Laura E. Gilcrist ◽  
Gregory S. Baker ◽  
Surajit Sen
Keyword(s):  
Surface Soil ◽  
Soil Dynamics ◽  
Soil Types ◽  
Mechanical Wave ◽  
Near Surface ◽  
Systematic Exploration ◽  
Wave Properties

scholarly journals Influence of cracking clays on satellite estimated and model simulated soil moisture

2010 ◽  
Vol 14 (6) ◽  
pp. 979-990 ◽  
Author(s):  
Y. Y. Liu ◽  
J. P. Evans ◽  
M. F. McCabe ◽  
R. A. M. de Jeu ◽  
A. I. J. M. van Dijk ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Surface Temperature ◽  
Soil Properties ◽  
Surface Soil ◽  
Clay Soils ◽  
Soil Types ◽  
Soil Porosity ◽  
Surface Soil Moisture ◽  
Near Surface ◽  
Community Land Model

Abstract. Vertisols are clay soils that are common in the monsoonal and dry warm regions of the world. One of the characteristics of these soil types is to form deep cracks during periods of extended dry, resulting in significant variation of the soil and hydrologic properties. Understanding the influence of these varying soil properties on the hydrological behavior of the system is of considerable interest, particularly in the retrieval or simulation of soil moisture. In this study we compare surface soil moisture (θ in m3 m−3) retrievals from AMSR-E using the VUA-NASA (Vrije Universiteit Amsterdam in collaboration with NASA) algorithm with simulations from the Community Land Model (CLM) over vertisol regions of mainland Australia. For the three-year period examined here (2003–2005), both products display reasonable agreement during wet periods. During dry periods however, AMSR-E retrieved near surface soil moisture falls below values for surrounding non-clay soils, while CLM simulations are higher. CLM θ are also higher than AMSR-E and their difference keeps increasing throughout these dry periods. To identify the possible causes for these discrepancies, the impacts of land use, topography, soil properties and surface temperature used in the AMSR-E algorithm, together with vegetation density and rainfall patterns, were investigated. However these do not explain the observed θ responses. Qualitative analysis of the retrieval model suggests that the most likely reason for the low AMSR-E θ is the increase in soil porosity and surface roughness resulting from cracking of the soil. To quantitatively identify the role of each factor, more in situ measurements of soil properties that can represent different stages of cracking need to be collected. CLM does not simulate the behavior of cracking soils, including the additional loss of moisture from the soil continuum during drying and the infiltration into cracks during rainfall events, which results in overestimated θ when cracks are present. The hydrological influence of soil physical changes are expected to propagate through the modeled system, such that modeled infiltration, evaporation, surface temperature, surface runoff and groundwater recharge should be interpreted with caution over these soil types when cracks might be present. Introducing temporally dynamic roughness and soil porosity into retrieval algorithms and adding a "cracking clay" module into models are expected to improve the representation of vertisol hydrology.

Influence of Acacia Trees on Near‐Surface Soil Hydraulic Properties in Arid Tunisia

2014 ◽  
Vol 27 (8) ◽  
pp. 1805-1812 ◽  
Author(s):  
Maarten De Boever ◽  
Donald Gabriels ◽  
Mohamed Ouessar ◽  
Wim Cornelis
Keyword(s):  
Hydraulic Properties ◽  
Surface Soil ◽  
Soil Hydraulic Properties ◽  
Near Surface ◽  
Soil Hydraulic

Cover crop effects on soil temperature in a clay loam soil in southwestern Ontario

2021 ◽  
pp. 1-10
Author(s):  
X.M. Yang ◽  
W.D. Reynolds ◽  
C.F. Drury ◽  
M.D. Reeb
Keyword(s):  
Soil Temperature ◽  
Cover Crops ◽  
Environmental Performance ◽  
Cover Crop ◽  
Crop Production ◽  
Surface Soil ◽  
Clay Loam ◽  
Near Surface ◽  
Soil Temperatures ◽  
Surface Soil Temperature

Although it is well established that soil temperature has substantial effects on the agri-environmental performance of crop production, little is known of soil temperatures under living cover crops. Consequently, soil temperatures under a crimson clover and white clover mix, hairy vetch, and red clover were measured for a cool, humid Brookston clay loam under a corn–soybean–winter wheat/cover crop rotation. Measurements were collected from August (after cover crop seeding) to the following May (before cover crop termination) at 15, 30, 45, and 60 cm depths during 2018–2019 and 2019–2020. Average soil temperatures (August–May) were not affected by cover crop species at any depth, or by air temperature at 60 cm depth. During winter, soil temperatures at 15, 30, and 45 cm depths were greater under cover crops than under a no cover crop control (CK), with maximum increase occurring at 15 cm on 31 January 2019 (2.5–5.7 °C) and on 23 January 2020 (0.8–1.9 °C). In spring, soil temperatures under standing cover crops were cooler than the CK by 0.1–3.0 °C at 15 cm depth, by 0–2.4 °C at the 30 and 45 cm depths, and by 0–1.8 °C at 60 cm depth. In addition, springtime soil temperature at 15 cm depth decreased by about 0.24 °C for every 1 Mg·ha−1 increase in live cover crop biomass. Relative to bare soil, cover crops increased near-surface soil temperature during winter but decreased near-surface soil temperature during spring. These temperature changes may have both positive and negative effects on the agri-environmental performance of crop production.

scholarly journals Signature of fault zone deformation in near-surface soil visible in shear wave seismic reflections

2013 ◽  
Vol 40 (6) ◽  
pp. 1074-1078 ◽  
Author(s):  
Ranajit Ghose ◽  
Joao Carvalho ◽  
Afonso Loureiro
Keyword(s):  
Shear Wave ◽  
Fault Zone ◽  
Surface Soil ◽  
Near Surface ◽  
Seismic Reflections ◽  
Zone Deformation

scholarly journals Crop, Tillage, and Landscape Effects on Near-Surface Soil Quality Indices in Indiana

2016 ◽  
Vol 80 (6) ◽  
pp. 1638-1652 ◽  
Author(s):  
W. Ashley Hammac ◽  
Diane E. Stott ◽  
Douglas L. Karlen ◽  
Cynthia A. Cambardella
Keyword(s):  
Soil Quality ◽  
Surface Soil ◽  
Quality Indices ◽  
Near Surface ◽  
Landscape Effects

Assessment of Near-Surface Soil Carbon Content Across Several U.S. Cropland Watersheds

Soil Carbon ◽  
2014 ◽  
pp. 249-257
Author(s):  
Diane E. Stott ◽  
Cynthia A. Cambardella ◽  
Douglas L. Karlen
Keyword(s):  
Carbon Content ◽  
Soil Carbon ◽  
Surface Soil ◽  
Near Surface ◽  
Soil Carbon Content
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