Showing 2 results for Water Potential.
A. Enferad, K. Poustini, N. Majnoon Hosseini, A. A. Khajeh-Ahmad-Attari,
Volume 7, Issue 4 (1-2004)
Abstract
In a pot experiment, the growth (Dry matter) responses of 18 rapeseed varieties to three levels of NaCl salinity induced by 1.2, 6, and 12 dS.m-1 were investigated using a factorial experiment with a randomized complete block design in 3 replications. The results indicated that salinity reduced total dry matter, Na concentration, K/Na ratio, ion selectivity of K versus Na, and leaf water potential while it increased K concentration. However, the leaf water potential of the plants had the highest and a significantly negative correlation with total dry matter accumulation. Therefore, it seemed that leaf water content of the plants could explain the tolerance or sensitivity responses to salinity. The rapeseed varieties were accordingly ranked into different groups. The varieties viz, Alice, Fonax, DP.94.8 and Licord were classified as saline tolerant group, and varieties such as Okapi, Akamar and Eurol as saline sensitive group. The remaining eight rapeseed varieties were moderately tolerant. Moreover, the response of rapeseed varieties viz. Consul, VDH8003-98 and Orient were different such that the above explanation could not be applied to them. Therefore, halophytic strategies for these three varieties might be worth further investigation.
Mustafa Goodarzi, Sayed-Farhad Mousavi, Majid Behzad, Hadi Moazed,
Volume 17, Issue 64 (9-2013)
Abstract
The transport process of chemical-fertilizers, radioactive materials and other solutes in soils and porous media is important to understand the environmental and economic effects of industrial, agricultural and urban waste disposal methods. In unsaturated porous media, large gradient in aqueous osmotic potential derives significant water vapor fluxes towards regions of high solute concentrations. In this research, the effects of osmotic potential (resulting from salinities of 0.5, 1 and 1.5%) on water vapor transport in three soil textures (silty clay loam, loam and sandy loam) were examined by using a physical laboratory model. Then, the experimental results were compared with Kelly and Selker (2001) model for validation of the predicted water vapor transport. The results showed that the rate of water vapor transport reduces significantly as soil texture gets heavier. For example, in salinity of 0.5% and 5th day of experiment, the amount of transported vapor in sandy loam, loam and silty clay loam soils was 0.362, 0.196 and 0.12 kg/m2, respectively. Large osmotic potential near the high solute concentration in soils caused significant vapor movement toward dense solutions. In salinity of 1.5%, transported vapor in these soils was 1.47, 0.723 and 0.38 kg/m2, respectively. Total water vapor movement until the 15th day was more than the 5th day. Comparison of experimental results with Kelly and Selker model results, using Mathcad PLUS 6.0 software, showed a good agreement between the observed and predicted data. Since water vapor delivered from uncontaminated soils to the contaminated soils can result in increased contaminant plume volume, these physical and chemical processes must be included in the predictive models of contaminant transport in the vicinity of concentrated sources
