Abstract The soil samples have been taken from a profile at the Research Station of College Agriculture in University Tikrit longitude 43 0 38 - 23 = east and latitude 34 48 40 north. were surface horizon with gypsum content 62 g.kg -1 (G1) also subsurface 443g.kg (G7) content. Different prepared as G2, G3, G4, G5, G6 that Gypsum contents 106, 153, 202, 245, 337 respectively. These by mixing gy...

Net ecosystem productivity of carbon (NEP) in seasonally dry forests of the Amazon varies greatly between sites with similar precipitation patterns. Correctly modeling the NEP seasonality with terrestrial ecosystem models has proven difficult. Previous modelling studies have mostly advocated for incorporating processes that act to reduce water stress on gross primary productivity (GPP) during t...

In the content of this study, non-linear consolidation behavior of unsaturated soils was investigated. In this respect a non linear differential equation for consolidation has been proposed. This proposed differential equation and its solutions enlighten both the diffusive characteristics and the time rate of settlement of soils. Besides, this study also enables to perform the matric suction ca...

[1] Measurements have been made of the effect of compaction on water retention, saturated hydraulic conductivity, and porosity of two English soils: North Wyke (NW) grassland clay topsoil and Broadbalk silty topsoil, fertilized inorganically (PKMg) or with farmyard manure (FYM). As expected, the FYM topsoil had greater porosity and greater water retention than PKMg topsoil, and the NW clay tops...

Orobanche crenata is a holoparasitic plant that is potentially devastating to crop yield of legume species. Soil temperature and humidity are known to affect seed germination, however, the extent of their influence on germination and radicle growth of those of O. crenata is largely unknown. In this work, we studied the effects of temperature, water potential (Ψt) and the type of water stress (m...

Control of water and air in the root zone of plants remains a challenge in the microgravity environment of space. Due to limited flight opportunities, research aimed at resolving microgravity porous media fluid dynamics must often be conducted on Earth. The NASA KC-135 reduced gravity flight program offers an opportunity for Earth-based researchers to study physical processes in a variable grav...

those fields. Both of these techniques, however, require more observations than are practical for most field manEstimation of mean water status in a field is crucial to effective agers. Efforts have been made to characterize fields irrigation water management. Problems encountered with the estimation of mean field soil water status may be attributed to spatial variabilfrom fewer observations. T...

The majority of hydraulic processes under a natural condition in a field are carried out under unsaturated flow conditions. The soil moisture retention curve (SMRC) is the most important hydraulic characteristic of an unsaturated soil whose knowledge is of prime importance in soil-water studies such as soil conservation, soil erosion, land evaluation, soil reclamation, and water resources manag...