فهرست مطالب لیلا جهانبان

Rapid technological advances in recent decades are despite the many benefits for human, exposed the natural resources and environmental components to various contaminants such as heavy and toxic metals.

In order to evaluate the potential of azolla, to absorb cadmium and micronutrient from solution contaning different concentrations of salinity, a factorial experiment with completely randomized design and three replications were conducted in the greenhouse. Cadmium was used from cadmium sulfate at the levels of 0, 5, 10, 20, 40, and 80 mg/liter using Epestin nutrient solution. The concentrations of NaCl in Epestin nutrient solutions were 0, 10, 20, 40 and 80 mM.

The azolla accumulated high concentration of cadmium solutions in their tissues. Assessing the effect of salinity on cadmium of the azolla indicated that increase in salinity levels of nutrient solution, increased cadmium concentration. Cadmium solutions increasing concentrations of cadmium (in plant), sodium, manganese, copper and decrease iron and zinc. Salinity treatments increased cadmium and sodium and decreasing concentrations of iron, zinc, manganese and copper. Mutual effects of cadmium and salinity treatments increased cadmium and sodium and decreasing concentrations of iron and zinc.

Aplications of cadmium and salinity decreased the growth rate of azolla and even caused death where their concentrations were high.

Salinity is an environmental problem in the world, especially in arid and semi-arid regions. High amounts of salts like sodium chloride (NaCl) in the soils and water have destructive effects on yield of plants. The harmful effects of salinity on plant growth are related to the low osmotic potential of the soil solution (water stress), the nutritional imbalance, the specific ion effect (salt stress), or the combination of these factors. The relationship between salinity and plant mineral nutrition is complicated. Under salinity stress, occurs the sodium and chlorine accumulation, resulting in ionic imbalance and the deficiency symptoms of nutrients in plants. The sodium (Na+) competes with the uptake of potassium (K+), calcium (Ca2+) and magnesium (Mg2+) by plant, and the chlorine (Cl-) with the uptake of nitrates (NO3-), phosphates (PO43-) and sulfates (SO42-).
In order to evaluate the tolerance of spinach cv. “virofly” to salinity levels in application with different nitrogen rates, a greenhouse experiment was conducted as completely randomized design based on factorial arrangement with three replications at Shiraz University Agricultural Faculty. Treatments include four levels of salinity (without salinity, 1, 2 and 3 gr of sodium chloride per kg of soil, equivalents to 0.7, 4.5, 8 and 11.5 dS/m in saturated solution extract of soil, respectively), and five levels of nitrogen (unfertilized, 75, 150, 225 and 300 mg N/kg of soil) as urea source. Nitrogen treatments were applied in two installments in water soluble (half before planting and another half, 20 days after planting). In order to prevent sudden stress, saline treatments were applied gradually after complete plant establishment with irrigation water. The irrigation of the pots was carried out with distilled water and at field capacity. After 56 days of sowing, in every pot the spinach shoots were discarded near the surface of the soil and the required parameters were measured.
The application of 4.5 and 8 dS/m salinity had no significant effect (≤0.05) on the relative yield and spinach leaf area, but 11.5 dS/m salinity significantly (≤0.05) decreased relative yield and spinach leaf area compared to without salinity level, 4.5 and 8 dS/m. Nitrogen application (75 and 150 mg/kg of soil) alleviated negative effect of salinity on yield and leaf area. Application of 225 and 300 mg N/kg of soil with 11.5 dS/m salinity significantly decreased the relative yield of spinach. The highest and lowest shoot water content changes in salinity conditions were observed in no-nitrogen application and 150 mg N/kg application, respectively, which shows that the application of nitrogen in the medium level controls the water changes in the spinach plants. In this study, increasing the amount of nitrogen at all levels of salinity, elevated the shoot water content. The tolerant plant species in the face of environmental stresses maintain the water content of their cells in the higher levels. Therefore, it can be said that the maintenance of high leaf water content is an important mechanism for tolerance to salinity, and the cultivars that can hold more water in their leaves under stress conditions, will have more tolerance to salinity stress. Linear regression (R2 = 0.8198) showed that in the salinity levels of 4.5 to 11.5 dS/m, there is a negative relationship between the yield and the chlorine to nitrogen ratio (Cl/N) of spinach shoots, so that with increasing Cl/N, the spinach shoot yield decreased by gradient of -3.077. Application of nitrogen up to 225 mg/kg of soil gradually reduced the ratio of K/Na, Ca/Na and Mg/Na, however, the application of 300 mg N/kg of soil had no significant effect on these ratios. The application of different levels of salinity gradually reduced the K/Na, Ca/Na and Mg/Na ratio.
The threshold of salinity of spinach cv. “virofly” was about 8 dS/m in our study, this was above the threshold mentioned (2 dS/m) for spinach in most sources. The application of nitrogen in medium level as urea can improve the negative effects of salinity in spinach but intensive nitrogen fertilization may increase the negative effects of salinity on plant yields.

A greenhouse experiment was conducted to study the effect of cadmium application on growth and nutrient concentrations in the duckweed under salinity conditions. The experiment was factorial arranged in a completely randomized design (CRD) with three replications. Factors were cadmium levels (0, 5, 10, 20,40, and 80 mg L-1 cd as cadmium sulfate) and salt concentration levels (0, 10, 20, 40, and 80 mM as sodium chloride) that added to Epstein nutrient solution. The results showed that cadmium and salinity, both alone and in combination, decreased relative growth rate of watercress. Cadmium concentration of duckweed increased by application of cadmium. Salinity increased cadmium concentration of duckweed. The application of cadmium and salinity, both alone and in combination, decreased nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, copper, sodium concentration. Manganese concentration increased by cadmium but decreased by salinity. In conclusion, duckweed accumulated the high concentration of cadmium, as is a cadmium accumulator plant, although high concentration of cadmium and salinity were causing plant death.

In order to study the effect of biological manure on efficiency of some manure mixtures and select the best manure combination to reach highest chickpea yield, an experiment arranged in randomized complete blocks design with three replications in Field Research of Payam Noor University of Arak. Treatments were different manure mixtures include: 1- No manure (Control), 2- Animal manure, 3- Vermi-compost, 4- Animal manure+ phosphorus and potassium powder, 5- Vermicompost+ phosphor and potassium powder,6- Animal manure+ phosphor and potassium powder+ biological manure include Iron and phosphate biological manure and rhizobium, 7- Vermicompost+ phosphor and potassium powder+ biological manure. Tested characters were plant height, number of primary and secondary branches, total biomass, 100 seed weight, seed yield, and content of N, K, Ca, Mn and Fe in plant. The results showed the effect of manure type was significant on all of the tested traits. The highest seed yield and growth criteria were obtained from two triple manure mixtures. In Animal manure+ phosphor and potassium powder+ biological manure and Vermicompost+ phosphor and potassium powder+ biological manure, use of biological manure by increasing plant necessary elements, respectively, caused to 6 and 7 percent increases in seed yield compare to without biological manure treats and 32 and 33 compare with control. On the basis of result, using biological manure caused to improve elements absorb, growth and seed yield of chickpea.

Organic matter is one of the most important factors in soil fertility. Different sources are involved in the supply of organic matter, including municipal solid waste compost, poultry and cow manure. These fertilizers often contain toxic substances and heavy metals which are extremely harmful for human and animal health. Toxicity and hazard of heavy metals in the soil is dependent on the form and amount of heavy metal. This research was conducted in a based on design completely randomized with three replications in Hamedan province. In this study, three types of soil texture (sandy loam, clay and loam) along with three types of organic fertilizers such as municipal solid waste compost, poultry and cow manure have been used in 5 levels (0, 20, 40, 80 and 120 Ton/ha). Availability and total concentrations of Zn, Cu, Ni, Pb and Mn were measured in each treatment. The results showed that soil cation exchange capacity (CEC) as well as availability and total amount of heavy metals were increased by enhancing the amount of organic fertilizers. The availability of heavy metals was much less than the total amount of elements. Overall, it was observed that increment of heavy metals caused by organic fertilizers was more in the clay soil compared to other soils because of the fact that clay texture showed high capacity for the uptake of heavy metals. Solid waste compost revealed the greatest effect on increasing the concentrations of heavy metals in the soil among other fertilizers while poultry manure was in the second place.

In recent decades, industrial, agricultural and urban activities have caused pollution and accumulation of heavy metals in soils and plants which directly or indirectly affects humans and animals lives. Nowadays, pollutant accumulation in most agricultural products is much higher than the permissible limit due to the excessive use of fertilizers.
In this study, the accumulation and distribution of heavy metals were investigated in different organs of rats under various nutritional conditions. The experiment was conducted in a completely randomized design with greenhouse strawberry treatments in three groups. Different groups of rats (27 rats) were fed strawberries infected with heavy metals by oral gavage within a three-month period.Regarding the average weight of rats, 0.5 gram of fresh strawberry was considered for each rat.
Results showed that the concentration of studied heavy metals in the strawberries were 7.7, 26 and 3.2 mg / kg for cadmium, lead and copper respectively, which were higher than Iranian standard level. The statistical results showed that there was a significant difference between the different organs in the intake of the heavy metals, so that in the infected treatment, the most and lowest amounts of cadmium were in the kidney (0.41 g / day) and the brain (0.24 g / day), respectively. Heavy metals caused reduction in the rate of weight gain of rats. The accumulation of these elements were higher in the kidney, liver and pancreas than other organs. The least accumulation of heavy metals was related to the rat’s brain, while highest amount of the heavy metals accumulation was in the kidney

In order to investigate the effect of intercropping corn and cucumber on weeds, a research project was carried out in a controlled field at Payame Noor University in Marivan (Kurdistan province) in 2013.The main plots consisted of two treatments (weeding and control) and sub-treatments including six treatments, i.e. 100% corn, 100% cucumber, 100% corn 100% cucumber, 50% cucumber 100% corn, 50% corn 100% cucumber and 50% corn 50% cucumber. After the preparation of the land in accordance with the patterns of different combinations of cultivation, was taken at the appropriate time.In weeding treatments, weeds were mechanically removed from the designated plots. In the time of harvesting of corn and cucumber, the land equity ratio (LER), photosynthetic active radiation (PAR) and dry biomass were measured. After corn harvesting, grain yield, biological yield and harvest index were calculated.The results showed that the effect of different planting treatments on grain yield was not significant. The effect of different weeding treatments and different planting combinations on corn and cucumber LER was not significant.On the other hand, the effect of weeding and different planting combinations on dry weight of weeds was significant.The highest dry weight of weeds was obtained in no weeding and 100% cucumber treatments, and the lowest dry weight of weeds was related to 100% cucumber, 100% corn and hand-weeding treatment.In general, PAR was the lowest for pure crop (corn), and the highest PAR was for mixed crops (corn and cucumber).

To study the efficiency of three priming methods to increase salt and drought stress resistant of safflower in germination and early growth, a laboratory experiment was conducted as factorial arranged in completely randomized design with four replications in seed laboratory of Iranian Plant Protection Research Institute. First factor was kind of stress include salt and drought stress, second factor was priming method include hydropriming (treated with water for 6 h), Halopriming (treated with NaCl 100 mM), KNO3 (0.5%) and no priming as control and third factor was water potential include 0.0, -0.3, -0.6, -0.9 and -1.2 MPa. Too, salt and drought conditions caused by NaCl and PEG respectively. Results showed that both stresses inhibited water uptake, germination percentage, radicle and Plumule length and seedling vigour index, but this criteria significantly were higher in NaCl than PEG at the same water potential. All of three used priming treatments increased germination and seedling growth under salt and drought stresses. By increase of stress intensity, efficiency of priming methods increased too. Hydropriming was more effective than other priming to decrease salt and drought damage in germination and early growth stages and it is suitable and low cost strategy.

This experiment was conducted to study the effect of effective organism (EM) application on efficacy of chemical and organic fertilizers in corn cultivation and their effects on yield as a factorial experiment on the base of complete randomized block design with four replications in research field of agricultural research center of Arak, Iran. Experimental factors were EM concentration included of three levels (0, 1:20 and 1:50) and type of fertilizer included of no application, fertilizer contain nitrogen, phosphorous and potassium (NPK: 300-135-100 kg/ha) and domestic manure (20 ton/ha). According to the results, the effect of type of fertilizer on all criteria and EM concentration on all of them except to length of maturity duration were significant. Interaction of fertilizer type and EM concentration was significant on plant height, leaf area index, nitrogen, phosphorous and potassium percentage of shoot, seed protein percentage and yield of dry and wet provender. On the base of results, simultaneous application of EM and domestic manure caused to increase necessary elements uptake of plant. So, yield of dry and wet provender was increased due to improvement of plant growth conditions. Difference between domestic manure and NPK on the point of nutrient uptake and yield of provender was high and significant in no EM application, low in 1:20 concentration of EM and non-significant in phosphor and potassium concentration and yield. According to the results, domestic manure efficacy was increased due to using effective microorganisms. So, in addition to yield increase, it caused to prevent chemical pollution due to using chemical fertilizer.