Search results for "Leaching model"
showing 9 items of 9 documents
Assessing Hydrus-2D to Simulate Soil Water Content (SWC) and Salt Accumulation Under an SDI System: Application to a Potato Crop in a Semi-Arid Area …
2015
In this paper the suitability of the HYDRUS-2D model to simulate volumetric soil water content in the root zone of a potato crop under subsurface drip irrigation (SDI) is initially assessed on the basis of a field study. Then, considering that the crop is moderately sensitive to soil salinity, the model is tested to predict the salt distribution around a buried emitter, when two different water qualities (i.e. electrical conductivity of 1.0 and 4.0 dS m-1) are used during the growing season (treatments T1 and T2). Finally, the soil volume in which salt accumulates is distinguished by the model for the two treatments, for which the respective yields are not significantly different. The resul…
Alfalfa crops amended with MSW compost can compensate the effect of salty water irrigation depending on the soil texture
2018
The availability of water resources of marginal quality such as drainage water or high-saltcontaining groundwater is turning into an important issue in Tunisia and other countrieswith scarce water resources. A pot experiment was carried out to evaluate plant produc-tion, nutrient content and heavy metal bioaccumulation in agricultural soils amended withMSW compost and irrigated with salty water, by using two different soil textures (clay andsandy). Salt water supply decreased plant dry yield in both soils. Salt stress had signifi-cantly reduction in plant biomass in sandy soil compared to those in clay soil (biomass ofdry weight is significantly higher in clay soil than those in sandy soil …
Application and evaluation of the SWAP model for simulating water and solute transport in a cracking clay soil
2005
In Sicily, the increasing scarcity of quality water is leading to irriga- from salinization (Crescimanno et al., 2004). tion with saline water in soils having a considerable susceptibility to In Sicily, the increasing scarcity of good quality water cracking. Irrigation systems involving high application rates are used coupled with intensive use of soil under semiarid to arid in these irrigated areas, and bypass flow during irrigation is thus climatic conditions, is leading to irrigation with saline prevalent. Adoption of management practices accounting for cracking water on soils having a high shrink-swell potential and is therefore necessary to prevent salinization and land degradation. su…
Assessing soil moisture regimes with traditional and new methods
2002
Soil moisture regime classes are required by U.S. soil taxonomy and other classification systems. Soil moisture regimes are based on long-term daily data of soil water content, which are as a rule estimated by means of models. International Commitee on Soil Moisture and Temperature Regimes (ICOMMOTR) has proposed classifying pedoclimate on the basis of biweekly water potential. This study was conducted to validate the use of the Erosion-Productivity Impact Calculator (EPIC) model in assessing soil water content of experimental fields placed in different European pedoclimatic conditions, to compare the pedoclimatic classification obtained with EPIC with those produced by the traditional Bill…
Long-term land-based and internal forcing of the nutrient state of the Gulf of Riga (Baltic Sea)
2004
Abstract The long-term nutrient trends (N, P, Si) in the Gulf of Riga and their driving factors were studied based on monitoring data from 1974 to 2000. Each nutrient showed individual temporal behaviour. The nitrate-N pool peaked in 1989–1990, but after that, the increasing trend switched to a decrease. The P pool, in turn, constantly increased till the mid-1990s; afterwards, a tendency was unclear. The obvious depletion of the silicate-Si pool reversed after 1995. Algal growth limitation responded to the changes in the nutrient pool. P deficiency during the vernal phytoplankton bloom in 1979–1990 switched to further alternate P or N limitation or co-limitation. Since 1991, Si shortage set…
Field and laboratory approaches for determining sodicity effects on saturated soil hydraulic conductivity
2006
Abstract Dilution of high-sodicity soil water by low-sodicity rainfall or irrigation water can cause declining soil hydraulic conductivity (K) by inducing swelling, aggregate slaking and clay particle dispersion. Investigations of sodicity-induced reduction in K are generally restricted to repacked laboratory cores of air-dried and sieved soil that are saturated and equilibrated with sodic solution before tests are conducted. This approach may not yield a complete picture of sodicity effects in the field, however, because of loss of antecedent soil structure, small sample size, detachment of the sample from the soil profile, reliance on chemical equilibrium, and differing time scales betwee…
Effects of agricultural management on surface soil properties and soil–water losses in eastern Spain
2009
Abstract In Spain, agriculture triggers soil degradation and erosion processes. New strategies have to be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. An experiment was designed to evaluate the effect of different agricultural management on soil properties and soil erosion. Five different treatments (ploughing, herbicide, control, straw mulch and chipped pruned branches) were established in “El Teularet experimental station” located in the Sierra de Enguera (Valencia, Spain). Soil sampling was conducted prior to treatment establishment, and again after 16 months, to determine soil organic matter content (OM), aggre…
The effect of alternating different water qualities on accumulation and leaching of solutes in a Mediterranean cracking soil
2002
The relevance of bypass flow on water flow, solute or pesticide transport is becoming increasingly recognized. Recent investigations proved that soil salinization may be influenced by bypass flow, i.e. the rapid transport of water and solutes via macropores and/or shrinkage cracks to subsoil and groundwater. This paper explores the role of bypass flow in the process of accumulation and leaching of solutes, as well as of sodium, in a Mediterranean cracking soil irrigated with saline/sodic waters. The results of bypass flow experiments performed on undisturbed soil cores showed that leaching of solutes occurred in concomitance with bypass fluxes when a low salinity solution was alternated wit…
Changes in soil redox potential in response to flood irrigation with waste water in central Mexico
2017
Irrigation with untreated sewage water adds fresh organic matter to the soil. When it is applied by flooding, as in the Mezquital Valley of Mexico, many of the pores in the soil become temporarily waterlogged and depleted of oxygen, and reduction generates nitrous oxide (N2O) and methane (CH4). We monitored the redox potential, Eh, in the soil at two sites in the Mezquital Valley to discover whether the short-term gaseous emissions matched the changes in Eh. One site is irrigated periodically by flooding with waste water and has alfalfa, rye grass and maize grown in succession; the other site grows maize with water from summer rain only. Each electrode buried in the soil for the purpose pro…