Hamid Reza Rahmani; Zahra Khanmohammadi
Abstract
Introduction: Vegetables are the main food of the world's population, especially in developing countries. Currently, many vegetables, especially leafy vegetables, have a high percentage of nitrate due to the overuse of nitrogen fertilizers to accelerate vegetative growth. Many researches have been done ...
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Introduction: Vegetables are the main food of the world's population, especially in developing countries. Currently, many vegetables, especially leafy vegetables, have a high percentage of nitrate due to the overuse of nitrogen fertilizers to accelerate vegetative growth. Many researches have been done on nitrate accumulation in crops worldwide, because of the harmful effects of excess nitrate in edible plants for humans and live stocks. Due to the necessity of such studies in country as well as the control of nitrate concentration in leafy vegetable and cucurbits, this study was done to investigate and monitor the nitrate concentration in some leafy vegetables and cucurbits (cucumber, tomato, potato, eggplant, pepper, onion, scallion and leafy vegetables) produced in some greenhouse and farms of Isfahan province. Materials and Methods: In this study 142 different leafy vegetables (coriander, basil, chives, parsley, garden cress, dill, tarragon, mint, fenugreek) and cucurbits (fruit vegetables) including (cucumber, tomato, eggplant, pepper, onion, scallion and potato in coarse and fine sizes) collected from greenhouses and agricultural fields of Isfahan, Dorcheh, Falavarjan, Tiran, Dastgerd, Dehaghan and their surroundings. Nitrate content of plant samples was measured by spectrophotometer based on colorimetric method after reduction and production of aminoazo color complex. Then the nitrate concentration in the samples was compared with the maximum allowable nitrate concentration in agricultural products provided by the National Standard Organization of Iran.Results and discussion: The results showed that the mean concentration of nitrate in cucumber samples was 1.48 times more than the Iranian National Standardization Organization (90 mg kg-1 of fresh weight); whereas the mean concentration of nitrate in potato, tomato and pepper samples was lower than the standard limits provided by National Iranian Standards Organization (170., 150 and 200 mg kg-1 of fresh weight respectively). The mean concentration of nitrate in fine sizes of potato, tomato and pepper was more than nitrate concentration in coarse sizes. Between the studied cucurbits, the highest and lowest average nitrate concentration were observed in cucumber and tomato respectively. Also the average nitrate concentration in cucumber skin was 16.7 times more than the mean nitrate concentration of its fruit. In general, the mean concentration of nitrate in leafy vegetables was more than the Iranian National Standardization Organization (1000 mg kg-1 of fresh weight). Between the studied leafy vegetables, the average concentration of nitrate in mint (457 mg kg-1 of fresh weight), fenugreek (262 mg kg-1 of fresh weight) and tarragon (695 mg kg-1 of fresh weight) was just lower than the Iranian National Standardization Organization. The others leafy vegetables probably have nitrate limitation for consumption. Conclusion: According to the results, it seems that fruit size is not a suitable criterion for plant nitrate content and the management aspects of farms play a major role in plant nitrate content. On the other hand, the changes of nitrate content in the farms are very high, so it cannot be clearly stated that the consumption of vegetables is restricted in terms of nitrate content. However, it seems that the consumption of vegetables produced in the studied areas may be restricted for consumers’ health in some cases.
Mehrcedeh Tafazoli; Hamid Jalilvand; Seyyed Mohammad Hojjati; Norbert Lamersdorf
Volume 15, Issue 2 , July 2017, , Pages 39-54
Abstract
Introduction: The amount of nitrogen compounds released into the atmosphere has increased, and is higher in industrial areas due to the increasing usage of fossil fuels and chemical fertilizers (Gruber and Galloway, 2008). Nitrogen deposition is one the consequences of increasing atmospheric nitrogen ...
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Introduction: The amount of nitrogen compounds released into the atmosphere has increased, and is higher in industrial areas due to the increasing usage of fossil fuels and chemical fertilizers (Gruber and Galloway, 2008). Nitrogen deposition is one the consequences of increasing atmospheric nitrogen compounds. Nitrogen deposition refers to a process that nitrogen compounds in the atmosphere deposit on a solid surface (Cornell et al., 2003). Due to the lack of information about the effects of nitrogen deposition on forest soil properties, the aim of this study was to investigate the effects of simulated nitrogen deposition on soil chemical properties in a maple plantation located at the educational and research forest of Faculty of Natural Resources (Sari). Material and methods: Twelve plots of 20 m × 10 m were established in the study plantation stand. Four nitrogen treatments were considered including zero (control), 50 (low), 100 (medium) and 150 (high) kg N ha−1 year−1. Nitrogen in the form of NH4NO3 solution was manually sprayed onto the plots monthly during one year. Three soil samples were taken seasonally at a depth of 0-10 cm in each plot using a coring method and were transported to the laboratory (Xingren et al., 2017). In the laboratory, the physical properties including water content and soil texture were measured by a weighing and hydrometer method, respectively. Chemical properties of soil including pH and EC were measured by potentiometric and electrical conductivity methods, respectively (Soil to water ratio 1:2.5). Soil organic carbon, total nitrogen, phosphorus and potassium were measured using the Walkley and Black method, Kjeltec System Instrument, Olsen P extracting solution and extracted using ammonium acetate, respectively. Results and discussion: The results showed that the nitrogen deposition had significantly decreased the pH and EC. At the end of the study period, the amount of nitrogen in medium (0.47%± 0.010) and high (0.59%± 0.013) treatments was significantly higher than the control (0.36%± 0.006). The amount of phosphorus in medium (15.95± 0.39 mg kg-1) and high (14.95± 0.43 mgkg-1) treatments was significantly lower than the control (24.97± 1.05 mgkg-1). In addition, nitrogen deposition had caused a significant reduction in soil potassium. The amounts of ammonium (low: 6.04, medium: 7.23 and high: 8.53) and nitrate (low: 7.21, medium: 9.95 and high: 20.51) were significantly higher than in the control treatment (ammonium: 4.93 nitrate: 5.06). The reason for reduced soil pH and EC can be the leaching of base cations followed by leaching of nitrate and an increased ammonium concentration in the soil. The reason for increased nitrate can be its addition as well as the production of nitrate in the presence of ammonium. In general, results showed that the nitrogen deposition treatments had destructive effects on soil chemical properties that decreased pH and EC, potassium and phosphorus and increased the total nitrogen, organic Carbon, ammonium and nitrate in the soil. Conclusion: Increased nitrogen at the early stages may be partly responsible for tree growth but, with the passage of time and the saturation of nitrogen in the soil and the occurrence of nitrate leaching as well as loss of soil fertility, conditions for the growth of plants would become unsuitable. Due to a lack of data on the effects of nitrogen deposition on soil properties, extensive studies about its effects on the soil chemical and biological properties, such as soil microbial and enzyme activities as well as soil respiration, is suggested.
Mohammad Nasri
Volume 12, Issue 4 , January 2015
Abstract
In order to optimize use of fertilizer on nitrate content and Quality characteristics in green beans (Phaseolous Vulgaris) genotype Sunray, experimental form of split plot design based on randomized complete block in the 2010 Crop Agricultural Research Station Varamin three was carried out. In this experiment, ...
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In order to optimize use of fertilizer on nitrate content and Quality characteristics in green beans (Phaseolous Vulgaris) genotype Sunray, experimental form of split plot design based on randomized complete block in the 2010 Crop Agricultural Research Station Varamin three was carried out. In this experiment, main plots, including urea nitrogen level 1-250 Kg ha-1. 2-300 Kg ha-13-350 Kg ha-1. Three fertilizer treatments include potassium and zinc: 1-120 Kg ha-1potassium. 2 -Foliar of 6 per thousand Zn. 3-120 Kg ha-1potassium and foliar of 6 per thousand Zn (based on soil test) has sub plot. Results of interactions showed that the highest levels of nitrate in pods consumed 350 Kg ha-1of nitrogen (sulfur-coated urea) application of 120 kg (K) was185.4 mg kg-1, The least amount of nitrate in the pod was 250 Kg ha-1(N) combined potassium and foliar Zn with 76.4 mg/kg. Highest level of fresh pod yield was achieved treatment used 250 Kg ha-1N and combined K and foliar Zn on 4306.2 Kg ha-1. The lowest this characteristic was achieved the treatments used 350 Kg ha-1of nitrogen (sulfur coated urea) and potassium applications with 2298.6 Kg ha-1. The highest Number of cutting in pod, Number of pod in plant, Number of pod in m2were achieved treatment used 250 Kg ha-1and combined K and foliar Zn 17.1number, 210.6 number and 1680 number, respectively. The most of Pod length, Number of seed in pod that were achieved application used 250 (N) Kg ha-1and K 18 Cm and 5.6 number respectively. The highest levels of 100 seed weight was achieved treatment used 300 Kg ha-1and combined K and foliar Zn. The lowest characteristic was achieved the treatments used 3250 Kg ha-1of nitrogen and Zn foliar with 36.1 gr. The highest pod yield (4306.2 Kg ha-1) was provided by application of 250 kg Urea.ha-1 with K and Zn fertilizers, however the lowest pod yields (2298 Kg ha-1) was observed at 350 Kg ha-1Urea with K.
Omid Bahmani; Saeed Broomand Nasab; Majid Behzad; Abd Ali Naseri
Volume 7, Issue 2 , January 2010
Abstract
Nitrate (NO3-N) and ammonium (NH4-N) leaching from agricultural soils can represent substantial losses of nitrogen (N) fertilizer, but a large variation in N losses has been reported. The objectives of this study were to assess the accumulation and movement of nitrate and ammonium in the soil profile ...
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Nitrate (NO3-N) and ammonium (NH4-N) leaching from agricultural soils can represent substantial losses of nitrogen (N) fertilizer, but a large variation in N losses has been reported. The objectives of this study were to assess the accumulation and movement of nitrate and ammonium in the soil profile over the study period under different irrigation and fertilizer conditions. So, N concentration and its leaching were studied under three N fertilizer and three irrigation treatments during 2007 Khuzestan Province, Iran. The irrigation treatments consisted of full irrigation (I1) and 85 (I2) and 70 (I3) percent of I1. Also, the N treatments were 150 (N1), 250 (N2) and 350 (N3) kg/ha. Soil sampling was conducted in June, July, August and September from the soil surface to 1.2 m depth at intervals of 0.3 m depth. We used the LEACHM model for nitrate (NO3-N) and ammonium (NH4-N) simulation, and their comparison with measured data. The amount of application of nitrogen and irrigation treatments indicated their important role in the accumulation of nitrate and ammonium in the soil profile. In this study, a high concentration of NO3-N was observed in I3N3 and also a high concentration of NH4-N accrued in the I3N3 and I3N2 treatment. After some time, Nitrate leached to subsurface depths and by the end of sampling (September) the concentration at the 0-30 cm depth was zero. The model was calibrated with a change in nitrification, denitrification and N volatilization for the three N treatments and model accuracy was increased after calibration so that Willmott's index for NO3-N and NH4-N after calibration was 0.56 to 0.98 and 0.76 to 0.96, respectively.
Leyli Gholamhosseini; Arash Javanshir; Amirhesam Hassani
Volume 5, Issue 1 , October 2007
Abstract
Dreissenapolymorpha (Zebra mussel) is a fresh water mollusk and native species of Caspian Sea area. These shells belong to filter feeder class and are able to filter a great volume of water. In this research, due to a wide range of materials available in urban wastewater efficiency of Dreissena polymorpha ...
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Dreissenapolymorpha (Zebra mussel) is a fresh water mollusk and native species of Caspian Sea area. These shells belong to filter feeder class and are able to filter a great volume of water. In this research, due to a wide range of materials available in urban wastewater efficiency of Dreissena polymorpha is studied to reduce concentration of Nitrate and Phosphate. The shell masses in 20, 40 and 60 g were put test for filtration tests and indirect absorption of nitrate and phosphate from artificial wastewater. These tests were performed in open system and were repeated 3-10 times depending on variance range.The results showed that there is a positive correlation between the weight of shell masses and the filtration rate of Nitrate and Phosphate in open system (R2 =0.99) and there is a negative correlation between concentration of Nitrate and Phosphate at the wastewater entry on one side and the filtration rate of nitrate and phosphate on the other side (R2=0.97) (t=2.132, P<0.023). It was found that when the weight of shell masses increase (from 20 to 40 to 60 g), the amount of Nitrate absorption is 0.08-0.2 mg.l-1 while Phosphate is absorbed 0.02-0.04 mg.l-1 in the open system. In this research it was found that Chlorella and Scenedesmus algae are able to reduce concentration of Nitrate (of at least 0.03 to 1.73 mg.l-1) and the Phosphate solved in waste water (of at least 0.42 to 4.48 mg.l-1).
Hamid Reza Nassery; Farshad Alijani
Volume 4, Issue 4 , July 2007
Abstract
The background hydrochemical system, the pollution sources, and the different pollutants of ground water in the Izeh plain, north east of Khuzestan, were determined and spatial and temporal variations of pollutants were studied. Groundwater samples from thirty four wells, one piezometer, and one Qanat ...
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The background hydrochemical system, the pollution sources, and the different pollutants of ground water in the Izeh plain, north east of Khuzestan, were determined and spatial and temporal variations of pollutants were studied. Groundwater samples from thirty four wells, one piezometer, and one Qanat have been collected in three periods of 2001. The nitrate concentrations of ground water in the Izeh plain increase, continuously, as a result of agricultural activities. The major process that cause increasing of nitrate concentrations in ground water is leaching of application of inorganic manure on cultivated areas. The maximum concentrations of nitrate in ground water of Izeh plain occur in May then the concentrations decrease during dry season. Although bacteria's adsorb on sandy silt layer overlying Izeh alluvial aquifer but shallow ground water are polluted bacterially
