Soil Profile

This report presents alternative emission limit values for inorganic components to be used in the revision of the Building Materials Decree (1999) in the Netherlands. Three key factors determine the emission limit value: (1) the environmental compartment under consideration, with its dimensions and the accounted for, (2) the desired level of environmental protection and (3) the scenario applying to the intended use of the construction material. Emission limit values have been derived here from modelled concentrations in soil, groundwater and surface water. The desired level of protection has been elaborated as a stand-still approach (based on quality target values and a risk-based approach (based on PNECs). Two exposure models were used for taking the effects of a time-dependent exposure of the soil to leached components into account, for vertical transport through the soil profile and for retardation of components in the soil profile. The PEARL model was used for binding described by equilibrium adsorption. The ORCHESTRA model was used for binding that also takes speciation into account. For surface water, a dilution factor was computed assuming a certain mixing zone, dependent on the size of the surface water. The consequences of the proposed alternative emission limit values have been estimated on the basis of information in a database containing results of leaching tests for construction materials. The alternatives proposed form the basis for a political decision-making process, where environmental protection will be balanced with other socio-economic concerns.

The LEACHM model developed by Wagenet and Hutson [1989] was used to predict the mineral nitrogen and water content in the soil under a winter wheat crop from February to April in two years and three locations. The model grossly overestimated soil water content, probably due to the bad fitting of the assumed water retentivity function to the experimental data at high water contents, and to the presence of a relatively shallow water table (1.0–1.5m). Measured soil hydraulic conductivity varied with water content in a different manner than predicted by the model. By assuming a sandy or gravelly soil layer between the bottom of the measured soil profile and the water table, prediction of soil water content improved considerably. Simulation showed that, under the experimental conditions studied, soil mineral nitrogen varied mainly due to the fertilizer additions, mineralization and denitrification. Nitrogen uptake by plants and leaching were small. Low values of nitrate leaching were pre...

Earthworm casts, formed when organic substrates and soil minerals pass through the digestive tract, may protect soil organic matter from biological degradation if they persist in the soil. Yet, the stability of casts is affected by their location in the soil profile because surface casts are exposed to more disruptive forces (wetting-drying, freezing-thawing) than subsurface casts. It is not known

Effects of lime and gypsum applications on the quality of soybeans grown under no-till (NT) are not well defined yet. A field trial established in 1998 on a dystrophic clayey Rhodic Hapludox, at Ponta Grossa, State of Paraná, Brazil, evaluated grain yield and soybean quality based on oil, protein and nutrient content, after lime and gypsum applications under NT, in a randomized complete block design (n = 3), split-plot experiment. In the main plots, the treatments with dolomitic lime were: control (no lime), split application of lime on the surface (three yearly applications of 1.5 Mg ha¹), surface lime (4.5 Mg ha¹), and incorporated lime (4.5 Mg ha¹). Subplots received four different rates of gypsum: 0, 3, 6, and 9 Mg ha-1. The soybean crop was evaluated in the agricultural years of 20022003 and 20032004. After 58 months, the correction of acidity through surface liming, with full or split rates, was more pronounced in the top layer (00.05 m) and there was greater reaction at the d...

An operational model for estimation of frost heave in field where stratified soil profile appears is presented. The model is developed from the research model described in part B. Soil layers are first classified into frost-susceptible layers (FSL) or non-frost-susceptible layers (NFSL). In an FSL, both heat flow and water flow are considered and ice lensing can occur. In a

Many agronomic and hydrological investigations depend on accurate measurement of soil water content (SWC). Accuracy, precision, facility and speed, including the capability to carry out measurements at different depths, are essential characteristics for monitoring SWC in the agronomical experiments. At the present, common systems use sensors based on capacitance (FDR) or time domain reflectometry (TDR) principles. Both the methods introduce advantages and disadvantages. In the framework of AQUATER Project (Decision support systems to manage water resources at irrigation district level in Southern Italy using remote sensing information), the main objective of this study has been to monitor the SWC dynamics in a tomato (Foggia) and watermelon (Castellaneta - TA) field cultivations, both located in Southern Italy, by using: (1) the Diviner 2000 (Sentek Pty. Ltd., South Australia), (2) the TDR-100 (Campbell Sci. Shepshed, UK), (3) ThetaProbe Soil Moisture Sensor-ML2x (Delta-T Devices Lt...

Many agronomic and hydrological investigations depend on accurate measurement of soil water content (SWC). Accuracy, precision, facility and speed, including the capability to carry out measurements at different depths, are essential characteristics for monitoring SWC in the agronomical experiments. At the present, common systems use sensors based on capacitance (FDR) or time domain reflectometry (TDR) principles. Both the methods introduce advantages and disadvantages. In the framework of AQUATER Project (Decision support systems to manage water resources at irrigation district level in Southern Italy using remote sensing information), the main objective of this study has been to monitor the SWC dynamics in a tomato (Foggia) and watermelon (Castellaneta - TA) field cultivations, both located in Southern Italy, by using: (1) the Diviner 2000 (Sentek Pty. Ltd., South Australia), (2) the TDR-100 (Campbell Sci. Shepshed, UK), (3) ThetaProbe Soil Moisture Sensor-ML2x (Delta-T Devices Lt...