scholarly journals Global rates of soil production independent of soil depth

2021 ◽  
Author(s):  
Emma Harrison ◽  
Jane Willenbring ◽  
Gilles Brocard
Keyword(s):  
Complexity ◽  
2015 ◽  
Vol 21 (6) ◽  
pp. 42-49 ◽  
Author(s):  
Allen G. Hunt
Keyword(s):  

2015 ◽  
Vol 23 (2) ◽  
pp. 47-55 ◽  
Author(s):  
Martina Slámová ◽  
Bruno Jakubec ◽  
Juraj Hreško ◽  
Boris Beláček ◽  
Igor Gallay

Abstract The soil production attributes of historical agrarian terraced fields were examined in the Budina cadastral area of the Ostrozky Mountains. This landscape represents a unique sub-mountainous Carpathian landscape with farms that use a historically preserved triple-field agricultural system. We determined the geo-spatial parameters of different types of land cover and terraces using geographic information systems. The soil depth was measured in the field, and the skeleton content was determined in the laboratory. We compared data regarding the potential production capabilities of the soil with data from the national classification of agricultural soils. Our results indicated that the soil productivity attributes improved because the naturally less fertile cambisols were positively affected by terracing and long-term cultivation. We recommend the preservation of traditional agricultural activities in historical terraced fields because these terraces represent valuable features that improve the quality of the landscape.


Soil Research ◽  
2005 ◽  
Vol 43 (6) ◽  
pp. 767 ◽  
Author(s):  
Marshall T. Wilkinson ◽  
Geoff S. Humphreys

New dating techniques are available for soil scientists to test fundamental pedogenic ideas. Recent developments in applications of terrestrial in situ cosmogenic nuclides (TCN) from bedrock and saprolite allow the derivation of soil production rates, at scales ranging from local (sub-hillslope) to catchment wide, generally averaged over timescales of 104–105 years. Where soil depths are relatively constant over time, soil production rates equal transport rates and are thus essential to establishing sustainable erosion rates. TCN also allow the form of the soil production function to be compared to theoretical models—a difficult task previously. Furthermore, parameterised soil production functions can now be incorporated into numerical surface process models to test landscape evolution ideas. Bedrock and saprolite conversion to soil is demonstrably dependent on the overlying soil depth, and there is general agreement that weathering declines exponentially beyond maximum soil production, consistent with theory. Whether maximum soil production occurs under a finite or non-existent soil cover at particular sites remains unresolved. We suggest that, in general, soil production from saprolite declines exponentially with increasing depth, while production from bedrock follows a humped function. Estimates of the role of flora, fauna and processes such as freeze–thaw that mix soil mantles to depth, have been limited prior to optically stimulated luminescence (OSL) dating techniques. Recently derived OSL mixing rates extend the magnitude of previous partial, short-term bioturbation rates. In fact, bioturbation appears to be the most active pedogenic process operating in many soils, with freeze–thaw environments a noted exception. Although bioturbation far outweighs soil production, it does not always lead to homogenisation as is often reported. We maintain that the above-ground component of bioturbation, i.e. mounding, may alone, or particularly when combined with particle sorting via rainwash processes, lead to horizonisation and texture contrast soils in those materials that can be sorted such as mixtures of sand and clay. Together, TCN- and OSL-based estimates of hillslope soil transport and bioturbation, suggest significant rates of downslope soil mantle movement coupled with rapid mixing, contrary to in situ soil development models.


Author(s):  
J.N. Abedalrahman ◽  
R.J. Mansor ◽  
D.R. Abass

A field experiment was carried out in the field of the College of Agriculture / University of Wasit, located on longitude  45o   50o   33.5o   East and latitude 32o 29o 49.8o North, in Spring season of the agricultural season 2019, in order to estimate the water consumption of potato crop using SWRT technology and under the drip irrigation system. The experiment was designed according to Randomized Complete Block Design (RCBD) with three replications and four treatments that include of the SWRT treatment (the use of plastic films under the plant root area in an engineering style), and the treatment of vegetal fertilizer (using Petmos), organic fertilizer (sheep manure), and the control treatment . Potato tubers (Solanum tuberosum L.)  var. Burin was planted for spring season on 10/2/2019 at the soil depth of 5-10 cm. The highest reference water consumption for the potato crop during the season was calculated by Najeeb Kharufa, which was 663.03 mm. The highest actual water consumption for the potato crop during the season for the control treatment was 410.1 mm. The results showed increase in the values of the crop coefficient (Kc) in the stages of tubers formation and tubers filling stage as compared to the vegetative and ripening stages, ranged from 1.37-1.92 for the two stages of tubers formation and tubers filling. The SWRT treatment gave the highest water use efficiency during the season, was 3.46 kg m-3 .


Author(s):  
Matt Bristow

A new analytical method is presented to determine the effects of cyclic loading on laterally loaded piles. The method uses a new numerical procedure to quantify the effects of the cyclic loading at each soil depth and convert that to a set of cyclic p-y modifiers. The reduced foundation stiffness associated with the cyclic loading can be determined, including the residual static capacity and an estimate of the accumulated displacement. The new method introduces the concept of cyclic degradation damage, which is defined as sum of the cyclic degradation that is occurring at each soil depth. Cyclic degradation calculations are based on the shear stresses in the soil. Consequently, anything that causes the shear stresses to change (e.g. pile length, pile diameter, applied loading, etc.) will automatically be included in the calculation of cyclic p-y modifiers. The method has been validated by comparing the cyclic p-y curves produced using the new method with established cyclic p-y curves derived from fielding testing. The new method has also been used to investigate what happens to the cyclic p-y modifiers as one moves away from the reference conditions used to determine the established cyclic p-y curves in API RP2A (2000). The new method shows that every application (e.g. combination of cyclic loading, pile properties, and soil characteristics) has its own unique set of cyclic p-y curves, though most p-y curves fit within an upper and lower bound range. Examples are provided for large diameter monopiles.


2020 ◽  
Vol 3 (2) ◽  
pp. 49-59 ◽  
Author(s):  
Yogesh Badhe ◽  
Ravindra Medhe ◽  
Tushar Shelar

The site suitability for construction of water conservation structures is an important step towards groundwater conservation in arid and semi-arid regions. Water is the most crucial for maintaining an environment and ecosystem which is helpful to sustaining all forms of the life. The increasing water scarcity day to day has been one of the common problems over a period of time. On top of it, when the area is a part of rain shadow zone like Ahmednagar district, water conservation activities are become more important. The present study aims to identify the suitable zones for water conservation activity. Multi- criteria evaluation is carried out using Geographic Information System (GIS) techniques to help the choice makers in defining suitable site for construction of water conservation structures. Different layers which were considered for multi-criteria evaluation: slope, land use land cover, soil texture, lithology, soil depth, soil erosion, wells, lineaments and drainage network. Analytical Hierarchy Processes (AHP) is used for weighted sum to find suitable sites for implementation of water conservation activity using selected criterions. The site suitability map was classified into four classes: highly suitable, moderately suitable, less suitable and not suitable with area of 19.19%, 26%, 49.03% and 5.78, respectively. This map will help for selection of suitable sites for construction of Mati Nala Bund (MNB), Check Dam, Cement Nala Bund (CNB) and Continuous Contour Trenches (CCT) for conservation of groundwater resource in the region.


1971 ◽  
Vol 2 (2) ◽  
pp. 79-92 ◽  
Author(s):  
K. J. KRISTENSEN ◽  
H. C. ASLYNG

The lysimeter installation described comprises 36 concrete tanks each with a soil surface of 4 m2. The installation is useful for plant growth experiments under natural conditions involving different treatment combined with various controlled water supplies. The ground installation is at least 20 cm below the soil surface and tillage can be done with field implements. The lysimeter tanks are provided with a drainage system which can drain the soil at the bottom (100 cm depth) to a tension of up to 100 cm. A constant ground-water table at less than 100 cm soil depth can also be maintained. The soil moisture content at different depths is determined from an underground tunnel by use of gamma radiation equipment in metal tubes horizontally installed in the soil. Rainfall is prevented by a movable glass roof automatically operated and controlled by a special rain sensor. Water is applied to the soil surface with a special trickle irrigation system consisting of a set of plastic tubes for each lysimeter tank and controlled from the tunnel. Fertilizers in controlled amount can be applied with the irrigation water.


2001 ◽  
Vol 66 ◽  
Author(s):  
M. Aslanidou ◽  
P. Smiris

This  study deals with the soil moisture distribution and its effect on the  potential growth and    adaptation of the over-story species in north-east Chalkidiki. These  species are: Quercus    dalechampii Ten, Quercus  conferta Kit, Quercus  pubescens Willd, Castanea  sativa Mill, Fagus    moesiaca Maly-Domin and also Taxus baccata L. in mixed stands  with Fagus moesiaca.    Samples of soil, 1-2 kg per 20cm depth, were taken and the moisture content  of each sample    was measured in order to determine soil moisture distribution and its  contribution to the growth    of the forest species. The most important results are: i) available water  is influenced by the soil    depth. During the summer, at a soil depth of 10 cm a significant  restriction was observed. ii) the    large duration of the dry period in the deep soil layers has less adverse  effect on stands growth than in the case of the soil surface layers, due to the fact that the root system mainly spreads out    at a soil depth of 40 cm iii) in the beginning of the growing season, the  soil moisture content is    greater than 30 % at a soil depth of 60 cm, in beech and mixed beech-yew  stands, is 10-15 % in    the Q. pubescens  stands and it's more than 30 % at a soil depth of 60 cm in Q. dalechampii    stands.


Geology ◽  
2000 ◽  
Vol 28 (9) ◽  
pp. 787-790 ◽  
Author(s):  
Arjun M. Heimsath ◽  
John Chappell ◽  
William E. Dietrich ◽  
Kunihiko Nishiizumi ◽  
Robert C. Finkel

2016 ◽  
Author(s):  
Arjun M. Heimsath ◽  
◽  
Oliver A. Chadwick ◽  
Joshua J. Roering ◽  
Shaun Levick

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