جستجوی مقالات مرتبط با کلیدواژه « Salinity Management » در نشریات گروه « آب و خاک »

This study conducted in order to assess accurate of Aquacrop Model in yield grain and Biomass simulation under rice(Hasham cultivar) deficit and saline irrigation management conditions in Rasht Rice Research Institute of Iran, during two year from 2009-2011. This experiment was conducted in form of factorial randomized complete block design with 3 replications. Treatments consisted of 4 levels of salinity as follows: S1, tap water with salinity less than 1 dS m, S2, S3, S4, respectively salinity of 2, 4, 6 dS m and five irrigation methods include I0: Irrigation continuous, I1, I2, I3, I4, respectively, in water saturation (AWD), irrigation at field capacity (FC), irrigation water content of 100, 90 and 80% of field capacity. AquaCrop model was evaluated for rice under deficit and salinity stress. Measured data of first and second year were used to calibrate and validate respectively. the root mean square error (RMSE), normalized root mean square error (RMSEn), the percentage relative error and test (T-test) was used in order to comparing simulation results with measured data. Grain yield was simulated with lower the threshold 0.85 and 9% to 0.43 and 33% in the model simulation results show that Model has acceptable performance in salinities less than the threshold salinity.

Rivers in addition to their environmental importance play a critical role in their neighboring people's lives. Karun River recognized as the most watery and longest river of Iran, in recent years, to declining flows and increasing the loading pollution sources to the river, its salinity has been increased. In this study, temporal and spatial changes in water salinity in the range of 105 km of Karun River from Mollasani to Farsiat were simulated using MIKE11 models. After calibration and validation of hydrodynamic and advection-dispersion model, numerical simulation results showed that in the effect of the loading of pollutants sources, salinity longitudinal profileespecially at the reaches of 60 and 90 km respectively positioned Ahvaz city and farmlands has increased as stepped. Maximum and minimum salinity changes take respectively place at the months of Aug. and Mar. To describe the rate of salinity variation in wetting and drying seasons, a fourth-order equation respectively with coefficient of determination of 0.99 and 0.98 was proposed. Results revealed that increasing flood discharge would lead to a significant decrease in the salinity of the river. In the month of Aug., removal of agricultural sources and in Mar., the removal of industrial and urban sources, have greatly influenced river salinity reduction at the upstream and downstream of Ahvaz, respectively. Results of this study can be used to study the effect of flow variation and pollution sources loading on the Karun River salinity and appropriate management solution provision.

Design and implementation correct drip irrigation plays an important role in increasing the productivity of agricultural land and help to using water low-quality. Attention to the problem of soil salinity¡ is determine the distribution pattern of soil salt is an effective tool for the proper management of soil. This study was done with goal to assess the two surfaces and subsurface drip irrigation system in olive trees in Tarom. In this regard¡ was discussed the pattern of distribution of mineral in soil¡ especially soil salinity and sodium adsorption ratio at various depths. Also distribution of soil salts were compared at in levels 50¡ 75 and 100% irrigation treatments. However¡ generally were obtained the concentrations of salt and sodium in different depths in this study in subsurface drip irrigation less than surface drip irrigation. Accumulation of Salinity and sodium in surface of soil in the top emitter in subsurface irrigation was greater than subsurface drip irrigation. Investigation different irrigation levels showed that in Spite of minerals reduction and leaching in irrigation level 100 percent¡ there isn’t significant difference in distribution of salinity and sodium between irrigation level 100 percent and 50 and 75.