Though it is vital to estimate infiltration as one of the key factors in effective management of water resources, only few studies have been carried out either to determine the infiltration or to compare the performance of infiltration models for coarse textured soils. Thus, the present study was conducted to accomplish two objectives. First to estimate the Horton’s infiltration model parameter...

Leakage rates are evaluated for a landfill barrier system having a compacted clay liner (CCL) underlain by a vadose zone of variable thickness. A numerical unsaturated flow model SEEP/W is used to simulate the moisture flow regime and steady-state leakage rates for the cases of unsaturated zones with different soil types and thicknesses. The results of the simulations demonstrate that harmonic ...

A 7-ha alfalfa field (Medicago saliva L. cv Mesa Sirsa) was sampled systematically on a 6 x 6-m grid by removing individual cores (2.54 cm diam) to a depth of 45 cm from each of the 1,936 grid intersections. The soil was mainly coarse-textured with a fine-textured streak running centrally, north to south. Nematodes were extracted by a semiautomatic elutriator and sugar flotation-sieving techniq...

Global models projected that, precipitation in Great Plains of the United States will decrease in summer and increase in spring and winter. However, few studies had carefully examined ecosystem responses to this intra-annual redistribution of precipitation. Here we used a process-based model, Terrestrial ECOsystem (TECO) Model, to evaluate responses of ecosystem carbon processes (including net ...

As soils store more carbon (C) than the Earth's atmosphere and terrestrial biomass together, balance between soil C uptake in form of organic matter (SOC) release as CO2 upon its decomposition is a critical determinant global cycle regulating our planet's climate. Although plant litter predominant source fuelling both build-up losses, issue how chemistry influences this remains unresolved. cont...

Aims Variation in precipitation strongly influences plant growth, species distributions and genetic diversity. Intraspecific variation in phenotypic plasticity, the ability of a genotype to alter its growth, morphology or physiology in response to the environment, could influence species responses to changing precipitation and climate change. Despite this, the patterns and mechanisms of intrasp...

Brassica cover crops are new to the mid-Atlantic region, and limited information is available on their N uptake capabilities for effective N conservation. Forage radish (Raphanus sativus L. cv. Daikon), oilseed radish (Raphanus sativus L. cv. Adagio), and rape (Brassica napus L. cv. Dwarf Essex) were compared with rye (Secale cereale L. cv. Wheeler), a popular cover crop in the region, with reg...