abstract soil quality is an essential concept for maximum agriculture production without environmental destruction. studying soil physical quality indicators, that express soil structural stability and soil air-water balance in root zone, is one of the most important aspects of soil quality. so determination of optimal range for pore volume distribution is important and this research carried ou...

cadmium is one of the most toxic pollutants in the surface soil layer the accumulation of which in soils as well as in crops is of increasing concern. in addition, zinc is a micronutrient in rice nutrition which is in interaction with cd. a pot experiment was carried out to study the effects of zinc and cadmium on rice growth and as well on concentrations of zn, cd, fe and mn in soil. a factori...

this paper develops positive mathematical programming (pmp) model to determine the optimum cropping pattern and water demand function in six regions of lower part lands of shirindarre dam in north khorasan province of iran and then estimates the expected pay for water in each region. the quantity of water supplied from such different water resources as dams, wells, and rivers in different scena...

abstract in order to analyse of soil volume humidity and water potential of turf using of different amounts of water absorbent polymer in sort of acryl amid potassium, an experiment conducted at research farm of meybod azad university in 2005. the experiment was conducted in randomized completed block design in four levels of polymers of 3, 6, 12 and 24 gr/m2 and 0 gr/m2 of polymers was conside...

BACKGROUND: One of limitation factor in agricultural plants production in dry areas, supply requires water. Also nutrition crop management is a necessary strategy for achieve sustainable agriculture. OBJECTIVES: Current study was conducted to assessment the effects of different irrigation regimes and several amount of nitrogen fertilizer on seed nutrition...

the planning of water resources is based on the volume of water extracted from the aquifer and accurate estimate of this volume considerably helps to development. in this study, the bayesian networks model using continues and clustering structures was used to simulate the groundwater level of birjand aquifer. bayesian networks was calibrated with five input variables of aquifer recharge, water ...

In this paper, the problem of turbulent forced convection flow of water- alumina nanofluid in a uniformly heated pipe has been thoroughly investigated. In numerical study, single and two-phase models have been used. In single-phase modeling of nanofluid, thermal and flow properties of nanofluid have been considered to be dependent on temperature and volume fraction. Effects of volume fraction a...