جستجوی مقالات مرتبط با کلیدواژه "ammonium nitrate" در نشریات گروه "کشاورزی"

This study was conducted to investigate the effect of Potassium Thiosulfate and Nitrate fertilizers on yield, water use efficiency and control of tuber cracking of potato cultivars. This research was conducted Factorial based on randomized complete block design with three replications at the National Potato Research Station located in Ardabil during 2021. The first factor includes Potassium Thiosulfate at three levels (zero, 10 and 20 liters per hectare with irrigation water), the second factor contains Ammonium Nitrate at three levels (based on soil test, 30% and 60% more than soil test) and third factor included four potato cultivars (Agria, Savalan, Anusha and Takta). The results showed that there was a significant difference between the levels of Potassium Thiosulfate fertilizer, cultivars, interaction effect of Potassium Thiosulfate fertilizer and Nitrogen fertilizer and tripartite interaction of Potassium Thiosulfate fertilizer, Nitrogen fertilizer and cultivars in terms of tuber yield, tuber number and weight per plant, plant height, main stem number per plant, water use efficiency, mean of number, length, width, depth and surface of tuber cracking. The highest tuber yield, tuber weight per plant and water use efficiency in the treatment of Potassium Thiosulfate fertilizer 10 liters per hectare and Nitrogen 250 and 328 kg.ha-1 in Takta cultivar, Potassium Thiosulfate fertilizer 10 liters per hectare and Nitrogen fertilizer 400 kg.ha-1 in Savalan cultivar and 20 liters per hectare of Potassium Thiosulfate fertilizer and 328 kg.ha-1 of nitrogen were observed in Savalan cultivar. Based on the results of factor analysis, in the treatment of zero liters per hectare of Potassium Thiosulfate fertilizer and 328 kg.ha-1 of Nitrogen fertilizer of Takta and Savalan cultivars; in the treatment of 10 liters per hectare of Potassium Thiosulfate fertilizer and 250 kg.ha-1of Nitrogen fertilizer in Takta and Agria cultivars, 328 kg.ha-1of Nitrogen fertilizer in Takta cultivar and 400 kg.ha-1 Nitrogen fertilizer in Anusha, Takta and Savalan cultivars and 20 Potassium Thiosulfate fertilizer per hectare and 250 kg.ha-1 Nitrogen fertilizer in Takta cultivar and 328 kg.ha-1 Nitrogen fertilizer in Savalan cultivar had the highest values in terms of tuber yield, tuber number and weight per plant, plant height and water use efficiency. Based on the results of cluster analysis, the fourth group includes treatments of 10 liters per hectare of Potassium Thiosulfate fertilizer and 250 and 328 kg.ha-1 of Nitrogen fertilizer in Takta cultivar and 400 kg.ha-1 of Nitrogen fertilizer in Savalan cultivar and 20 liters per hectare of Potassium Thiosulfate fertilizer in 328 kg.ha-1 of Nitrogen fertilizer in cultivar was in Savalan cultivar and in terms of tuber yield, tuber number and weight per plant, plant height, water use efficiency had the highest amount and without the number of tubers with crack in the plant.

Due to the increase in the consumption of fossil fuels and chemical fertilizers, especially nitrogen-containing fertilizers, the entry of nitrogen into the cycle of ecosystems has been more than normal.Nitrogen deposition as a consequence of increasing nitrogen input to the atmosphere, can be a threat to ecosystems. It can affect soil properties, soil microorganisms and their activities, vegetation and animals. The aim of the present study is to investigate the effects of deposition of different rates of atmospheric nitrogen on the biochemical properties of a summer rangeland's soil.

For this purpose, the seeds of Medicago sativa were planted in 36 pots containing rangeland soil in a completely randomized block design.  Two months after seed germination in pots, six Nitrogen treatments included control,30, 60,90,120 and 150 kg ammonium nitrate/ha which dissolved in water were applied in 6 replications during a period of 75 days. At the end of experiment, some soil biochemical properties (acidity, electrical conductivity, absorbable phosphorus, total nitrogen, organic carbon and exchangeable potassium along with biomass and microbial respiration) and Root weight and depth factors were measured.  Data analysis was done using analysis of variance method and mean comparison was done using Duncan's test.

The results demonstrated that increasing the level of ammonium nitrate deposition to 60 and 90 kg per hectare per year, despite the significant increase (p < 0.05) of organic carbon and total soil nitrogen, causes a significant decrease in other measured biochemical properties of the soil (p < 0.05). An increase in nitrogen deposition in the early stages may be partially responsible for root growth, but with nitrogen saturation in the soil and the occurrence of nitrate leaching, as well as the loss of soil fertility, unfavorable conditions for root growth are provided. With the increase of nitrogen deposition in the soil, up to the level of 60 kg /ha, the average respiration and microbial biomass increased, But at higher levels of  nitrogen deposition, respiration and microbial biomass decreased.

In case of an increase in mineral nitrogen deposition in the studied area, it is recommended to use the Medicago sativa in the improvement of vegetation restoration projects of summer rangelands to absorb the deposed mineral nitrogen in excess of the soil holding capacity, its alleviate negative consequences and creating a suitable root zone for the the  activity of soil microbial.

Nitrogen is the most important nutritional element required by the rice plant, and a large part of it is lost in paddy fields through leaching, which can lead to environmental problems and reduce the efficiency of urea fertilizer use in rice cultivation. Therefore, the present experiment was conducted with the aim of investigating the effect of using different organic and chemical nitrogen fertilizers in order to reduce or solve this problem in 2021, in a split plot experiment based on a randomized complete blocks design with three replications was implemented.The main factor including humic acid, fulvic acid and application of nitrogen fertilizer (granular urea, sulfur coated urea, ammonium sulfate, urea and ammonium nitrate, combination of sulfur coated urea and granular urea, and control) were considered as secondary factors. Comparison of the average of simple effects showed that the highest yield of paddy was obtained with the application of humic acid, which increased by 19% compared to the control. The highest plant height and biological yield were obtained by applying sulfur coated urea or sulfur coated urea with granulated urea. The highest dry weight of the cluster per plant, a single plant dry weight and the number of fertile tillers in plant belonged to the application of sulfur coated urea or the co-application of sulfur coated urea with granular urea with humic acid application. Therefore the fertigation of humic acid can be useful in improving the growth of rice in rice-cultivated soils in Khuzestan.

In order to investigate the effect of different sources of organic fertilizers and nitrogen on some of the physiological, quantitive and qualitive characteristics under direct cultivation, a field experiment in the crop season 2020-2021, in a split plot experiment based on a randomized complete block design with three replications were implemented in Ahvaz. the main factor at three levels (humic acid, fulvic acid and control) and the use of nitrogen fertilizer at 6 levels (granulated urea fertilizer, sulfur coated urea, ammonium sulfate fertilizer, urea and ammonium nitrate, sulfur coated urea and granulated urea fertilizer and no application of nitrogen fertilizer as a control) were a secondary factor. Mean comparison of simple effects showed that the highest percentage of total protein of leaf, rice yield, hectoliter weight, rice grain length, white grain width after cooking and the lowest percentage of grain crushing after bleaching were observed by humic acid application. The increase in rice yield, rice grain length and white grain width after cooking in humic acid application treatment compared to the control was 19.4, 5.4 and 5.6 percentage respectively. The highest percentage of total protein of leaf, rice grain length, white grain width after cooking and the lowest percentage of grain crushing after bleaching were obtained by applying sulfur coated urea or sulfur coated urea with granular urea. The mean comparison of interaction effect of the factors on other studied traits showed that the highest leaf area index was observed with the application of sulfur coated urea or the application of sulfur coated urea with granular urea × application of fulvic acid and the highest amount of chlorophyll a, b, carotenoids and white grain length after cooking belonged to the treatment of application of sulfur coated urea along with granular urea × application of humic acid. It seems that the supply and availability of nitrogen in the soil at different growth stages of rice under the application of nitrogen fertilizer treatments and the improvement of soil characteristics due to the use of organic fertilizers and as a result of sufficient access to nutrients at different stages of plant growth and development, improvement of physiological characteristics, has affected the quantity and quality of rice. Based on the results of this experiment, it seems that the combined application of humic acid or fulvic acid with sulfur coated urea fertilizer or sulfur coated urea with granulated urea is recommended in similar conditions.

To investigate the effects of different nitrogen sources including ammonium nitrate, asparagine, and glutamine in five concentrations of 0, 50, 100,150, and 200 mg l-1 on some physiological and biochemical characteristics of rosemary (Rosmarinus officinalis L.), an experiment was conducted in a completely randomized design with five repliacations. The indices including plant height, shooting rate, number of leaves, necrotic leaf size, chlorophylls a, b, and total chlorophyll content, and the content of carotenoids, phenols, and flavonoids were measured. The results showed that the nitrogen sources significantly (P≤0.01) affected the all measured indices except the necrotic leaf size. The results of means comparison showed that the highest shooting rate and number of leaves were obtained at 100 mg l-1 of glutamine and asparagine and the highest plant height was obtained at 200 mg l-1 of ammonium nitrate. Also, the highest amount of photosynthetic pigments was obtained at 50 mg l-1 of asparagine and the highest amount of phenols and flavonoids was related to 200 mg l-1 of glutamine. In general, the results showed that the various nitrogen sources studied could positively and significantly improve the morphological and physiological characteristics of rosemary under in vitro conditions.

Human demand for food and energy has led to major changes in the level of active nitrogen (N) released to the atmosphere. N addition experiments are a reliable way for investigating the effect of extra N deposition on target ecosystems. The present study was carried out to investigate in the effects of an artificial N deposition on the soil biochemical properties of a 20-year-old oak (Pinus radiata) plantation in Hyrcanian forests in the north of Iran. Twelve plots of (20 m × 10 m) were established in the study area. Four N treatments were considered: zero (control), 50 (low), 100 (medium) and 150 (high) kg N ha−1 year−1. N in the form of NH4NO3 solution was manually sprayed onto the plots monthly for one year. Analysis of variance showed that soil characteristics at nitrogen treatment and different seasons and interaction of season and treatment had significant differences (P value <0.01). In this regard and at the end of the simulation period, the lowest soil pH was observed in high treatment (6±0.3) and highest in control treatment (6.8±0.3). The highest amount of total nitrogen was observed at high N treatment (0.55±0.02). But in relation to K and P concentrations, the control treatment (368±2.7) (12±1.6) had highest and high N treatment (266±3) (6.6±0.7) had lowest concentration of P and K, respectively. In this study, due to the increase in nitrate content obtained by adding ammonium nitrate in the nitrogen simulation process, nitrate becomes saturated in the soil and mobile in the soil, and then leaching with base cations and decreasing soil pH.

To evaluate the effect of different levels of nitrogen and iron on some quality indices and yield parameters of "Granny Smith" apple a factorial experiment, in a completely randomized block design with three levels of nitrogen (0, 144 and 288 g ammonium nitrate per tree( and three levels of iron (0, 1500 and 3000 mg Fe-EDDHA per tree) as soil application, was conducted during 2015. Nitrogen application increased chlorophyll index and yield efficiency. The highest chlorophyll index (58.77) and yield efficiency (0.889 Kg.m-2) were observed in 288 g/tree ammonium nitrate. Iron application increased pH of fruit juice and fruit iron concentration, and decreased leaf K concentration. Positive correlation between total antioxidants and leaf Fe concentration (r = 0.84), a* parameter and leaf Fe concentration (r = 0.68), leaf K content and leaf N content (r = 0.69), fruit K content and fruit N content (r = 0.74), leaf N and fruit N content (r = 0.66) was observed. In conclusion, nitrogen application at 288 g/tree was more effective in improving the mentioned characteristics. Iron nutrition had no much impact and seems that more concentrations of iron are required to a greater effect.

Aquifers are vulnerable to pollution from industrial and agricultural activities, the share of the agricultural sector is higher than the rest. Nitrogen fertilizers have the highest consumption in agriculture. Nitrate ion with negative charge is not absorbed by soil particles; therefore, it is subjected to surface and ground water leaching which is more intensive in sandy loam. Analytical and numerical models are used to investigate nitrate transport between soil and groundwater and its effect on groundwater contamination. The application of these models depends on the determination of dispersion and retardation factors. Therefore, quantitative estimation of these factors is necessary to solve the problems related to solute and metal transport in the soil. The parameters were estimated by comparing laboratory and field data versus theoretical ones. The objective of this study is to determine dispersion and retardation factors of nitrate and ammonium ions with three different methods including breakthrough curve (BTC), least square and HYDRUS models in a saturated sandy loam soil. The study was conducted in the soil columns of 50 centimeter and 10.5 diameter with three replications. Before leaching, ammonium nitrate fertilizer was added to soil columns with concentration of 10 g per liter. Concentration of nitrate and ammonium in leached water at the end of soil column with time, commonly known as the breakthrough curve (BTC), is determined. BTC as the first method, resulting from a step input of solute is often of sigmoidal shape and the dispersion and retardation factors are determined with this curve. The second method was least square one. In this method an error function model that fits to a breakthrough curve is presented with two unknown parameters. The parameters can be estimated by using laboratory data and a least square method. The last method is HYDRUS model. In HYDRUS model, the convection-dispersion and mobile-immobile models through inverse modeling were used to estimate the parameters. Dispersion and retardation factors for nitrate ion were in the range of 0.09-0.15 and 0.44-0.48 and for ammonium ion were in the range of 0.042-0.053 and 0.24-0.37, respectively. For quick and accurate estimation of dispersion and retardation factors from a soil column data, three methods were used in this study. The models applied in this study have almost identical results in estimating dispersion and retardation factors. The nitrate ion has been absorbed into the soil particles more than ammonium ion and consequently has a lower dispersion and retardation factors and less leaching than ammonium ion.

In this research, effects of iron and nitrogen nutrition in three concentration (Iron chelate 0, 5 and 10 ppm and Ammonium nitrate, 0, 40 and 60 ppm) were evaluated on nitrogen, potassium and phosphorous contents in fruits and leaves of apple (cv. Fuji) in harvesting time and on fruit quality during storage. The experiment was carried out using a factorial completely randomized block design (CRBD) with three replications in 2013. Results showed that nitrogen treatment had no significant effect on fruit quality, except Vitamin C content that significantly increased. Iron nutrition mainly decreased the fruit weight loss during the storage. Storage time affected fruit quality and decreased that, which after 95 days, fruit were more injured. During the storage, Vitamin C, fruit firmness, dry weight and total acid were decreased. Nitrogen nutrition increased the nitrogen content in fruits and leaves but decreased potassium level in these organs. Iron treatment had no significant effects on nitrogen and phosphorous contents but significantly decreased potassium content in fruits. These results indicated that, storage of Fuji cultivar for three month had no reducing effects on quality.

Nitrate (NO3-) and ammonium ion (NH4) in the soil differ for their effects on yield quantity and quality of tobacco. Climatic and edaphic factors and agronomic management can undermine their differences. With the increase in leaf yield, chlorine and nicotine content of the leaves and on the contrary, by reducing potassium content, nitrogen, has the opposite effect on the quantity and quality of tobacco leaves. Tobacco farms do not consume urea fertilizer in the country and farmers believe that the use of urea result to the late tobacco and tobacco leaf color is inappropriate technology.
Material and Two field experiments were conducted in Oromieh and Titrtash in 2014 to study the interactive effects of nitrogen resources) urea (ammonium) and nitrate ammonium fertilizers (and application pattern on yield quantity and quality of tobacco. The treatments were factorial arrangement of nitrogen resources and application patterns of basal, 2/3 basal and 1/3 after initiation of rapid growth (AIRG, about three days after transplanting), 1/2 basal and 1/2 AIRG, 1/3 basal and 2/3 AIRG) with 3 replications based on randomized complete block design. Dry leaf yield, gross revenue, average price of tobacco, chlorophyll, nicotine, sugar, ash, chlorine, potassium, plant height and leaf area index were measured. Analysis of variance was performed using SPSS software.
Finding: The results indicated that the leaf yield was higher in Tirtash than Oromieh. In terms of leaf yield, the best application pattern for urea and nitrate ammonium was 2/3 basal and 1/3 AIRG, and 1/3 basal and 2/3 AIRG, respectively. Regarding potassium content of cured leaf, urea was better than nitrate ammonium for Tirtash. But for Oromieh, it was vice versa. Nicotine content was only affected by application pattern; the 1/2 basal and 1/2 AIRG was the best for nicotine content. Ammonium nitrate caused lower accumulation of chloride in leaf than urea. Generally, although urea and nitrate ammonium did not differ for leaf yield, but they can enhance leaf quality (potassium content) in Tirtash and Oromieh, respectively.
As a conclusion it can be said that the effect of nitrogen source on leaf yield was not significant. In other words, no difference between urea and ammonium nitrate in terms of leaf yield.The results dispel the ambiguities use of urea fertilizer in the tobacco field and given the relative abundance of urea relative to ammonium nitrate fertilizer domestic production of these fertilizers, the problems facing tobacco farmers in different regions in the preparation of ammonium nitrate fertilizer eliminated.

Production of medicinal crops in soilless culture systems and controlled environments provides an opportunity for increasing the quantity and quality of primary materials of medicinal plants. A factorial experiment based on completely randomized design was carried out with four culture systems (aeroponics, nutrient film technique, classic hydroponics and soil) and three different nitrogen sources (nitrate, ammonium nitrate and ammonium) and three replications. Results indicated that vegetative traits such as plant height, stem and root diameter, number of lateral branches and leaf area were affected by culture system and source of nitrogen. Plants grown in aeroponics fed by ammonium nitrate had the highest plant height and root and stem diameter. The results also showed that nitrogen source and culture system had significant effect on root dry and fresh weight, shoot dry and fresh weight and root yield per hectare. Maximum and minimum of these parameters were observed in plants fed with ammonium nitrate in aeroponics and ammonium in aeroponics system, respectively. According to the results, ammonium nitrate is recommended as the most proper nitrogen source for production of licorice in aeroponics system.

In order to evaluate the effect of different levels of benzyladenine, nitrogen and salinity on growth characteristics of pistachio seedlings, cv. Badami Zarand, a factorial experiment with three factors: benzyladenine (0, 250 and 500 mg/L), nitrogen (0 and 100 mg N/kg soil as NH4NO3) and salinity (0 and 2000 mg NaCl/kg soil) was carried out as completely randomized design with three replications for 24 weeks under greenhouse conditions. Results showed that although salinity significantly decreased dry weight of shoots and roots of the seedlings, but application of 500 mg/L benzyladenine increased dry weight of shoots and roots by 125 and 86 percent, respectively. However, simultaneous application of nitrogen and benzyladenine increased dry weight of shoots and roots more than 3 and 2 folds, respectively. Results also showed that salt stress significantly decreased leaf area and length of root system. But simultaneous application of nitrogen and the highest concentration of benzyladenine increased leaf area and length of root system more than 3 and 2.5 folds, respectively. The results of triple effects also showed that although height, leaf number and stem diameter significantly decreased under saline conditions, but simultaneous application of nitrogen and benzyladenine resulted in more prominent increase of these growth characteristics than individual application of these treatments. Finally, it is concluded that simultaneous application of nitrogen and benzyladenine resulted in more effective reduction of harmful effects of salinity on growth characteristics of pistachio seedlings than application of these treatments alone.

Regular watering and application of nitrogenous fertilizers in turf-grasses is a conventional operation, especially in warm and dry or semi-dry climates, which arecommon in many parts of Iran. Nitrogen is a mobile nutrient in soil or substrates, especially in the form of nitrate. Nitrate leaching due to the regular watering has been reported in many sources. The managing nitrogen application can help to minimize the loss of this element regarding the ability of soil-plant system. Attempts have been made to control the growth of turf-grass using various types of chemicals, but similar to the concerns associated with the consumption of nitrogenous fertilizers, this is also concerned with environmental pollutions. Therefore, the growth of turf grasses can be controlled without using chemicals and by limiting the use of nitrogen and managing the irrigation.The purposes of this study were to limit the application of nitrogen in order to control vegetative growth of the turf grass and maintain its visual quality, and to manage irrigation in order to preserve this mobile element (nitrogen) near the root system and prevent its leaching.
The effects of reduced water and nitrogen supply on the control of vegetative growth of turf grasses, commonly named as sport turf,were evaluated.Therefore, an experiment was designed in a factorial based on randomized complete block design with three replications. Mixed seeds of sport turf grass were planted with the density of 40 g m-2in boxes, which placed atthe depth of30 cm and leveled with sandy loam soil in mid-spring. Nitrogen was applied as ammonium nitrate via fertigation in five levels of 0, 0.5, 1, 1.5 and 2 mg m-2 month-1, andirrigation treatments performed at four levels of 100%, 80%, 60 % and 40% of field capacity. Watering was done every two days for 5 months during the warm season of the year after the first mowing on June 2013. Some traits such as plant height, fresh and dry weight, density, color and quality, and chlorophyll and proline contents were evaluated during growth period or at the end of the experiment.The data were subjected toananalysis of variance (SAS, 1996),and differences among the treatments were compared using Duncan’s multiple range test at 95% probability level.
The results showed that decreasein nitrogen level up to 0.5 gdid not significantly change density index,,whilethe index showed a significant reduction in treatment containing zero nitrogen application and the lowest irrigation regime (40% of the field capacity).Quality and color of the turf grass had no significant correlation with nitrogen treatment, while the factor was significantly decreased when irrigation regime of 40% of the field capacity was applied. It was determined that although color of the turf grass was greener with lower levels of water,a good color was found with high level of non-organic fertilizer at the time that the amount of nitrogen leaching was also limited. Therefore, regardless of the different nitrogen levels applied, quality and color indiceswerethe lowest when irrigation at 40% of field capacity was applied. Limiting the level of nitrogen up to 0.5 gramand irrigation up to 60% of field capacity was desirable to control and reduce the height of turf grass. Reduction in water level up to 80% of field capacity caused no significant changes in fresh weight, but a significant decreasewas resulted with the reduction of water consumption up to 60% of field capacity. The maximum fresh weight was found with 1.5 grams nitrogen. However, reducing nitrogen level upto 0.5 gramdid not bring about significant changes in this trait. Dry weight also followed the same pattern as fresh weight. Although reduction in the level of applied nitrogen did not reduce the height, it caused a significant reduction in fresh and dry weight of the turf grass. The highest chlorophyll content was found when 2 grams of nitrogen and irrigation regime of 40% of field capacity were used. Regardless of the nitrogen level, the highest chlorophyll content was found in irrigation of 40% of field capacity,while the lowest amount was observed in the treatment containing irrigation at100 and 80% of field capacity. Plants were dark green in 40% of field capacity. Proline content showedincreasealong with the decrease inirrigation as well as nitrogen levels.
Plant height, fresh and dry weight, chlorophyll and proline contents were significantly affected by limiting the use of nitrogen and water, but density and quality indices were not significantly influenced. Regardless of the nitrogen levels applied, quality and color traits were the lowest only in irrigation regime of 40% of field capacity. Therefore, it was concluded that reduction of nitrogen supply to 1 mg m-2 month-1and irrigation regime up to 60% of field capacity could result in thereduction ofvegetative growth of turf grass, while quality traits were not affected negatively.

In order to study the changes in chemical forms of zinc in the rhizosphere of two tuber plants and their relationship to plant uptake in a polluted soil, sequential (Tessier et al., 1979) and single step extraction methods were used. In this research, three radish cultivars (Raphanus sativus) and two turnip (Brassica rapa) cultivars were planted in a complete randomized design pot experiment with four replications (20 pots) and 4 pots with no cultivation as blank. Results indicated that the largest forms of zinc include Fe and Al oxide bounded carbonates, and the residual forms respectively. The exchangeable and soluble forms comprise only less than one percent of total zinc in the rhizospheric soils of all plants. The zinc concentration of shoots for different cultivars of each plant did not show significant difference and in all plants the zinc accumulation factor and the translocation factor were less than unit. Sequential and single step extractions showed significant increase of Zn in the rhizosphere of both plants compared to bulk soil. Different cultivars of both plants could significantly increase the rhizosphere DOC up to 9 mg.L-, which consequently increased soluble and exchangeable Zn in this zone for both plants compared to bulk soil.

In order to investigate the effects of nitrogen fertilizer type and split application of fertilizers، an experiment was conducted in experimental field of Lorestan University as split plot experiment based on complete randomized block design with four replications. In this experiment seven nitrogen treatments were in the main plots and two corn hybrids (short season and full season) were in the subplots. The Results showed that by increasing the amount of both nitrogen fertilizers grain yield and biological yield of corn hybrids increased. Using urea in comparison with ammonium nitrate has higher effects on grain yield of corn hybrids. For both of corn hybrids and especially for full season hybrid split application of nitrogen fertilizers have positive effects on grain yield. Based on results split application of urea has higher positive effects on grain yields of corn hybrids.

To study the effect of type and different nitrogen fertilizers on controlling Egyptian Broomrape، field and greenhouse studies based on randomized complete block with three replications، were conducted at Ferdowsi university of Mashhad. Greenhouse study treatments were consisted of ammonium nitrate، ammonium sulfate and urea each of which applied at four rates (75، 150، 300 and 350 kg/ha). Field experiment treatments were included of ammonium nitrate، ammonium sulfate and urea، applied at three rates (150، 300 and 350 kg/ha). The result of greenhouse studies indicated ammonium nitrate and urea (at all of rates) reduces Orobanch infestation about 80 percent. Ammonium nitrate and urea at (300 kg/ha) were increase tomato dry weight compare to the control. The field study findings too indicated that ammonium nitrate (300 kg/ha) was the most effective treatments in increasing tomato yield and produced highest yield (53 t/ha). Ammonium sulfate strongly decreased tomato biomass plants in greenhouse study but in field conditions produced yield same control. In conclusion we may suggest that applying ammonium nitrate fertilizer could effectively control broomrape in tomato and improve tomato growth and biomass.

To evaluate the effects of nitrogen sources and rates on yield and yield components of cucumber a factorial pot experiment with completely randomized design and twenty treatments and three replications were conducted at the green house of agricultural education center in Tabriz, Iran, in 2009. Treatments of the study consisted of factorial combinations of four nitrogen sources (urea, sulfur coated urea, ammonium nitrate and ammonium sulfate) and five rates of nitrogen (0, 150, 300, 450 and 600 kg nitrogen per hectare). Traits measured in the study were fruit yield, number of fruit per plant, fruit length and diameter. Results of the variance analysis of data showed that the main and interactive effects of nitrogen source and rate were significant on fruit yield and length at 1% probability. The highest fruit yield (640.2 g/plant) was obtained from the application of 600 kg nitrogen per hectare as sulfur coated urea. The highest fruit length and number of fruit per plant were also obtained from this treatment. Comparison of the means values showed that the lowest fruit yield was in the treatment with ammonium nitrate.