فهرست مطالب معصومه شادان

Zeolites have been developed to utilize in agricultural sector due to their high water holding capacity and cation exchange. In this research, the effect of zeolite on evaporation from the soil surface and volume of drainage water in sandy loam soil was investigated. For this purpose, the HYDRUS-2D model was used to simulate evaporation and drainage and the required data was collected by conducting pot experiments. The studied treatments included four levels including zero, 5, 10, and 15 grams of zeolite gr kg-1 of soil. Four irrigation frequency were done on bases of readily soil moisture and the soil moisture values before and after irrigation events were measured using the Wet sensor in the depth and radial directions and recorded for 45 days. The initial amounts of evaporation and the volume of drainage water were determined by using the water balance equation and measuring the drainage water output, respectably from the pot at each stage. The results showed that increasing in the amount of zeolite cause to decries the amount of evaporation from the soil surface and the volume of drainage water in the treatment of 15 grams of zeolite by 17.11% and 20.6%, respectively. The coefficient of determination (R2) for HYDRUS-2D model simulation varied between 0.90 and 0.93. The value of the efficiency factor (EF) of the model, which shows the quality and the fitting of the observed and estimated data, is between 0.59 and 0.98 for evaporation and between 0.86 and 0.92 for the drainage water volume. These results show the high efficiency of the model in simulating the mentioned parameters.

Nitrogen is one the most important nutrients in achieving optimal yield of crops. The objective of this study was to investigate the effect of clinoptilolite zeolite on nitrate ion adsorbstion and growth indices and cucumber parameters including, number, weight, length and diameter of the cucumber. This research was conducted at greenhouse of the Faculty of Agriculture of Urmia University and in completely randomized design experiment with four levels including 0, 5, 10 and 15 gr zeolite per kg of sandy loam soil in three replications with drip irrigation system.The results show that zeolite has positive effect of on reducing nitrate leaching at p < 0.01 level.Comparing the averages, it showed that there was a statistically significant difference between the control treatment and 15 g zeolite per kg of soil. Also, results showed that the application of zeolite on crop yield (Multiplied by fruit number in fruit weight), number of fruits, leaf area and plant diameter was significant at p < 0.01 level and also on fruit weight, fruit diameter, fruit length and plant height at p < 0.05 probability but had significant effect on leaf number. Increasing amount of zeolite cause to increase yield by 2.6 time greater than control treatment.