Geoderma
Infiltration is the key process in the rainfall-runoff relationship. Little is known, however, about the seasonal and spatial variability, which is important for the behaviour of the slope surface geomorphological processes.The infiltration rates for contrasting slopes in southeast Spain have been measured by means of simulated rainfall and ponding. A north- and a south-facing slope were selected...
The carbon isotopic composition of soil CO 2 was measured during the winter of 1990/91 at two sites in the Lublin Upland (Poland). In that season a period with very low air temperature occurred, during which snow covered soils were frozen. We observed variations of δ 1 3 C up to 3 permil. During freezing periods the variations depended on soil physical properties. In sandy soil...
To predict the contamination risk of drinking water in a water catchment, regionalization methods, in which regional transferability is presupposed by assigning areas of same qualities, are used. Those methods use soil information at the field scale to build up soil profiles, which serve as input for one-dimensional simulation models of water and solute transport together with management data. These...
Weathering rates for soil profiles and catchments developed on greywacke and shale parent materials have been calculated using four common methods cited in the literature (conservative element depletion, the PROFILE model, catchment input-output mass balance (budgets) and the MAGIC model). A comparison of the results suggests that for any single method the results are consistent. However, comparison...
The independent comparison of a three-dimensional data set from a large soil block (5 m 3 m 1 m) with output from a one-dimensional model of soil water and solute transport (LEACHC) is considered. The lack of work comparing site-specific solute breakthrough with model predictions is outlined. A statistical method of limiting the number of runs required to provide a good representation of model...
This paper aims to determine the quantitative impact of land qualities on rubber production, using the theory of fuzzy logic. This theory is applied in a land suitability assessment for rubber production in the northern part of the rubber growing area of peninsular Thailand. The proposed method differs from the usual technical land evaluation procedures by (1) the use of an explicit weight for the...
Soil and soil solutions from the Martinelli Slope Experiment on Niwot Ridge, Front Range, Colorado (40°3′N, 105°36′W) were studied to evaluate the influence of pocket gophers (Thomomys talpoides) on nutrient cycling in the alpine soil environment. Concentrations of total C, N, exchangeable Ca and K were significantly lower in gopher mound soils (P < 0.05), whereas available NO3− and nitrogen fluxes...
We examined the consequences of deforestation and pasture establishment for soil chemical and physical properties and for soil organic matter content, in Rondônia, in the southwestern part of the Brazilian Amazon basin. Two chronosequences were selected. One chronosequence consisted of a forest and pasture established in 1989, 1987, 1983, 1979 and 1972. The main soil type in this area is the red yellow...
Episodic desert loess and paleosol sequences in South Yemen provide a late Pleistocene to Holocene record of climatic change and soil development. At Sana, one paleosol based on its thickness and development formed during mid or early Holocene time in approximately four thousand years. The 2Akb horizon sample of this paleosol has a 14C age of 7750 ± 300 years. At Ibb the 2ABtb horizon of another paleosol...
The large, unconfined lysimeters at the San Dimas Experimental Forest, in southern California, provide a unique setting in which to study decade-scale vegetation effects on mineral weathering. We investigated the 2:1 phyllosilicate mineralogy of lysimeter soils under 41-year-old monocultures of scrub oak (Quercus dumosa Nutt.) and Coulter pine (Pinus coulteri B. Don), and compared the results to archived...
Soil and soil solutions from the Martinelli Slope Experiment on Niwot Ridge, Front Range, Colorado (40°3′N, 105°36′W) were studied to evaluate the influence of pocket gophers (Thomomys talpoides) on nutrient cycling in the alpine soil environment. Concentrations of total C, N, exchangeable Ca and K were significantly lower in gopher mound soils (P < 0.05), whereas available NO3− and nitrogen fluxes...
Episodic desert loess and paleosol sequences in South Yemen provide a late Pleistocene to Holocene record of climatic change and soil development. At Sana, one paleosol based on its thickness and development formed during mid or early Holocene time in approximately four thousand years. The 2Akb horizon sample of this paleosol has a 14C age of 7750 ± 300 years. At Ibb the 2ABtb horizon of another paleosol...
This paper aims to determine the quantitative impact of land qualities on rubber production, using the theory of fuzzy logic. This theory is applied in a land suitability assessment for rubber production in the northern part of the rubber growing area of peninsular Thailand. The proposed method differs from the usual technical land evaluation procedures by (1) the use of an explicit weight for the...
We examined the consequences of deforestation and pasture establishment for soil chemical and physical properties and for soil organic matter content, in Rondônia, in the southwestern part of the Brazilian Amazon basin. Two chronosequences were selected. One chronosequence consisted of a forest and pasture established in 1989, 1987, 1983, 1979 and 1972. The main soil type in this area is the red yellow...
The large, unconfined lysimeters at the San Dimas Experimental Forest, in southern California, provide a unique setting in which to study decade-scale vegetation effects on mineral weathering. We investigated the 2:1 phyllosilicate mineralogy of lysimeter soils under 41-year-old monocultures of scrub oak (Quercus dumosa Nutt.) and Coulter pine (Pinus coulteri B. Don), and compared the results to archived...
Pollutant transport in sandy soils can be very complex due to the presence of coarse sand lenses. Water flows laterally over the coarse material and, subsequently, breakthrough occurs in concentrated pathways, called fingers. This (funneled) flow process is a form of preferential flow reducing solute travel time and degradation of organic chemicals.In this paper, we test ground-penetrating radar (GPR)...
A need exists for information regarding the stability of wetting fronts in field soils because they increase the vulnerability for groundwater contamination. In this study, we develop a simple approach for the evaluation of wetting front stability in dry soils. We show that the stability of wetting fronts in the top layer of a soil depends both on the type of soil and the intensity of the precipitation...
Results of many independent experimental findings related to fingered preferential flow are combined into a concise, conservative engineering methodology for predicting pollutant transport through fingered flow paths. Preferential flow can occur in all textures of soil, with fingering occurring in less structured coarse soils, giving over to macropore flow in finer-textured soil regimes. A simple...
Wetting front instability resulting in fingered flow has been found in both wettable and nonwettable soils. Understanding how and when this phenomenon occurs under field conditions is greatly limited. Laboratory research has resulted in a number of expressions for finger diameter. In this paper we test the applicability of one of these equations for three different soils in the Netherlands where detailed...