B et te r C ro ps /V ol . 9 7 (2 01 3, N o. 4 ) Silicon is a major component of sand, silt and clay minerals. Because of this abundance, it typically has not been considered as a limiting factor in soil fertility. However numerous fi eld studies have shown that supplying crops with adequate plant-available Si can suppress plant disease, reduce insect attack, improve environmental stress toleran...

The models that were analyzed using FLAC version 4.0 (FLAC, 2000) are shown on Figure 5.1. The models have different soil types: loose silty sand with 20% fines content (Figures 5.1a and 5.1b), soft clay (Figure 5.1c), and silt (Figure 5.1d). Hence, the determination of the parameters is different for each model. The following sections discuss the determination of the parameters used in the ana...

with Kd values. 0.29. Not very detailed.Dickens and Wehtje1986 Kd values: 0.04-0.6 kg/L at 0-20 cmKd values: 0.019-0.036 kg/L at 65-95 cmOnce herb leaches past the top 10 cm of soil, retardation of herbicides would be slight.Contamination of ground water would depend on rate of decomposition. Composition of soils determined, but soil types not classifiedKoskinen et al.<l...

Hydraulic erosion associated with seasonal freeze-thaw cycles is one of the most predominant factors, which drives soil stripping and transportation. In this study, indoor simulated meltwater experiments were used to investigate sorting characteristics transport mechanism sediment particles under different conditions (unfrozen, shallow-thawed, frozen slopes) runoff rates (1, 2, 4 L/min). Result...

accurate knowledge of spatial distribution of soil physical and chemical properties is needed for suitable management and proper use of rangelands in masileh plain, qom, iran. in present study, for the spatial modeling of chemical and physical parameters such as sodium (na), calcium (ca), soluble potassium (k), magnesium (mg), electrical conductivity (ec), saturation percentage (sp%), silt, cla...