A successful water management scheme for irrigated crops requires an integrated approach that accounts for water, crop, soil and field management. Most existing models are designed for a specific irrigation system, specific process such as water and solute movement, infiltration, leaching or water uptake by plant roots or a combination of them. There is a shortage in models of a generic nature,...

Coupled heat and water transport in soils has enjoyed extensive focus in soil physics and hydrology and yet, until recently, there has never been a satisfactory comparison of water vapor ̄uxes measured in the ®eld with theory. At least two factors have led to this, ®rst, most of the experimental work has been laboratory oriented with steady state boundary conditions imposed and second, there ha...

F Pesticide Contamination Prevention Act authorrzed the California Department of Food and Agrculture to modify w.es of pesticides in areas where they have leached through soil to groundwater (Connelly, 1985). Leaching of agriculhuaI chemicals has been shown to occur during recharge of groundwater whereby water moves from the surface through the soil profile to a groundwater aquifer (Wehtje et a...

long-term application of fertilizers containing p, especially organic fertilizers, usually increases the water soluble and available p of soil and at the same time may result in p accumulation in soil. organic fertilizers may also increase movement of p in the soil profile that could result in surface and ground water pollution. an experiment was conducted on field plots that received three app...

for a determination of optimum levels of water and nitrogen fertilizer, as regards corn yield and nitrate movement in soil, a split-plot experiment, using a randomized complete block design of three replications was conducted in safiabad agricultural research center, on a silty clay loam soil. three irrigation levels (50, 75, and 100% of water requirement) and three nitrogen fertilizer levels (...

Nitrogen management continues to be diffi cult due to transformations of nitrogen fertilizers that are possible when applied to soil and the uncertainties of weather (Cabrera et al., 2008). Nitrogen (N) fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to l...

In this work a dynamic model of water uptake from plants growing in naturally vegetated areas subjected to a rainfall and evaporation time series is described. The model results are compared and contrasted with popular pre-existing models. Also, the effects of the uptake pattern on the movement of water across multiple soil layers are also analyzed. The results showed that contrary to common mo...

Physical protection of soil carbon (C) is one of the important components of C storage. However, its exact mechanisms are still not sufficiently lucid. The goal of this study was to explore the influence of soil structure, that is, soil pore spatial arrangements, with and without presence of plant residue on (i) decomposition of added plant residue, (ii) CO2 emission from soil, and (iii) struct...