Journal of Agricultural Sciences and Natural Resources
Year:2008 | Volume:15 | Issue:2|Papers Count:33

This research has been done in order to recognize vegetative characteristics of seedlings from Avicenna marinas seeds to rehabilitate suitable sites of this species. The seeds were collected from mother trees in August. Propagates were classified by diameter in three classes (1, 2 and 3). In the nursery, 900 seeds were grown in two sections: 1.450 seeds with bark 2.450 seeds without bark in the effect of two factors: seed class in three levels (1, 2 and 3) and pot volume in two levels (1.7 and 5.2 lit). The pots were contained by sand and irrigation system was dropping. After 4 months, the seedling height, collar diameter and number of leaves in every seedling were measured. The results showed that desirable growth of seedling was earned in below condition respectively: 1. seed class no.1 with bark in small pot. 2. Seed class no.1 without bark in big pot. 3. Seed class no.2 without bark in big pot. 4. Seed class no.2 with bark in small pot. 5. Seed class no.3 without bark in big pot. 6. Seed class no.3 with bark in small pot and also it is better that using of seed class 1 for production of one year old seedlings in reforestation and the other seeds give more time for growing.

In order to investigate on the potential of the Landsat7 ETM+ and IRS-1C imagery for forest extent mapping and determining forest extent changes in the Zagros forests from 1955 to 2002, a case study was accomplished at the Armerdeh forests, Baneh, west of Iran. The forest extent map in 1955 was produced using a digital aerial photo mosaic. The ETM+ and IRS-1C images were used to generate the forest extent map in 2002. The images were geo referenced using GCPs and digital elevation model. Radiometric and geometric quality of images was investigated. Results of quality investigation showed that band1 and band 4 of LISSIII sensor have considerable radiometric errors so that they cannot use for this study. The Rationing transformations, vegetation indices, tasseled cap transformation, and principal components analyses were applied to the ETM+ imagery to generate arithmetic bands for classification. In addition, the panchromatic images of ETM+ and IRS-1C with multi spectral bands were merged using IHS and automatic statistical PANSHARP techniques. After selecting some pixels as training area for forest and non-forest classes, the best set of bands for classification were chosen using seperability indices. The images were classified with supervised classification to forest and non-forest classes by maximum likelihood, parallel piped and minimum distance classification algorithms. In addition, the best sets of bands were classified to six classes i.e. forest, agriculture, garden, rock and urban area. The results of classifications were assessed using a ground truth map of points gathered using GPS from a systematic sampling network. The results showed that using the best selected ETM+ bands could better classify forest and non forest areas than other images by the maximum likelihood algorithm with 81.3% overall accuracy and 0.64 Kappa coefficient. The result of forest extent change detection using forest map of 1955 and 2002 showed that 4853 ha of the forest area have been reduced and 953 ha increased in this period.

The kenaf samples at the present research were prepared from a digitated leaf variety 7635 (Hibiscus cannabinus), in Varamin Cotton Investigations Center. Kenaf bast fibers have been separated from woody cores of whole kenaf plants and were cut to 4-5 centimeter pieces after washing with tap water, air dried and consequently used for making kraft pulp. Under different cooking conditions (Sulfidity 25%, Cooking temperature 170oC, Liquor to chips ratio 7:1, active alkali of 14, 16 and 18% and cooking times of 30, 50 and 75 min), several pulps in the pulp yield ranges of 50 to 60 % and kappa number of 17 to 30, were obtained. The results of kenaf pulp evaluations have shown that, the independent effects of active alkali and cooking times on kappa number and pulp yield were significant at 99% confidence, but their corresponding effects were significant for kappa number and insignificant for pulp yield at both 95 and 99% confidence levels. Based on the relations between pulp yield and kappa number, three different treatments in the kappa number ranges of 20, 25 and 30 were selected. In order to determine the appropriate kappa number and refined pulp freeness in terms of optimum paper properties, hand sheets of kenaf bast fiber kraft pulps at different levels of kappa number and pulp freeness of 400, 450 and 500 ml, CSF, have been evaluated. The results have shown that, kenaf bast fiber kraft pulp at kappa number of 25 and pulp freeness of 400 had better quality in case of overall paper properties.

In this study a mathematic model was developed for predicting wood temperature at different depth of wood and time during heating. Fractional differential equations were applied for developing such model. For evaluating accuracy of the model beech wood with density of 0.68gr/cm3 and moisture content of 12 percent was used. Good agreement was found between model predictions and experimental data. Effect of distance from heat resource in wood was explained however with increasing wood thickness or distance from heat resource accuracy of the model reduced. Effect of duration of heating on heat transfer was also described well. Heat loss from edges of wood block under effect of environmental conditions was identified by model. However model has to be modified for increasing its accuracy, it had high ability for predicting temperature at different thickness of wood during heating. When accuracy of the model is increased it can be used for wood drying and heat treatment applications.

Pulp producing in vast scale using mechanical and semichemical methods such as: thermomechanical (TMP), chemei-thermomechanical (CTMP) and chemei-mechanical (CMP), because of saving raw material and producing high yield pulp are the main important issue, which is being developed and implemented recently, and is considered more than the past. Finland, Sweden and Canada involved in the above mentioned issue more than other countries. Although chemeimechanical pulp production does not pass on more than two decades in Iran, but there has been a lot of research progress in the field of pulp and papermaking processes. Pulp preparing, using above mentioned methods needs wood with low density, therefore, fast growing trees such as paulownia and poplar are being pay attention. Paulownia grows faster than poplar, and hence produces shorter fibers. Comparison between paper strength made out of pure poplar and paulownia pulp showed significantly difference, because of different fiber reaction during refining. On the other hand, from paper strength tests were found, that poplar pulp longer fibers are refined easily and better than paulownia, then gives the paper better strength as well. During refining, poplar longer pulp fiber is broken to shorter fiber and caused less difference between the two pulp fibers. Therefore, tearing, burst, tensile, stiffness and breaking length of paper made up from poplar pure pulp and poplar pulp with 10% added paulownia were found significant difference between them in 1% level. Opacity of paper made out of from poplar pulp with 10% added paulownia, is increased, meanwhile folding strength is decreased. Optimum cooking time for paulownia and poplar wood, in order to reach the pulp yield about 85%, while the cooking temperature is 160 Cº and wood to liquor ratio 1:7, are 100 and 90 minutes respectively. Regarding to the results of this study, producing chemei-mechanical pulp from paulownia and the possibility of adding to poplar chemei-mechanical pulp, is drawn promising horizon to meet wood demand in pulp and paper industries.

The aim was to investigate the use of reed, as a substitute for wood, in laboratory made 3-layer particleboard in order to supplement the supply of raw material for the Iranian particleboard industries. The ratio of the mixture of reed and wood particles, in the surface and middle layers were 20:80, 30:70, 40:60, respectively. Press temperatures were chosen at two levels of 165 and 185oC. Three levels of urea formaldehyde resin were selected for the surface layers, namely: 8, 10 and 12 percent. Control samples were also made from wood particles only, under industrial production conditions. Then, the MOE, MOR of the boards were measured. Failure modes were investigated based on the topography and the “clearness level” of the fracture zone. In general, the results show that reed has a positive effect on the mechanical properties of boards because of the higher slenderness ratio of reed particles which promote better adhesion and densification. In this research, the treatment with 40% reed, 12% resin in the surface layers and a 185°C press temperature has resulted in an optimum reed board product.

Micromorphological properties of a loess-paleosol sequence in Naharkhoran area, south of Gorgan were studied in order to assess the paleoenvironmental conditions of the area. Seventeen soil successions were observed across Naharkhoran loess sequence and their morphological properties were described. The undisturbed samples for the preparation of thin sections were collected. The micromorphological observations revealed many evidences on the occurrence of pedogenic processes. The existence of hypocoatings and nodules of Fe and Mn oxides indicates that the studied sequence had periodic fluctuations of redox conditions. Other characteristics of this succession are evidences of biological activity such as faunal excrements, root residues in channels and bioturbation evidences as granular microstructure. The presence of gastropoda shells, possibly points to the dominance of drycool climatic conditions during loess accumulation. Biogenic calcite of cytomorphic and needleshaped types in paleosols is other indicators for favorable climatic conditions and the consequent decay of organic matter. Clay coating and hypocoating are present only in paleosols, which is the evidence for adequate rainfall and moist climatic conditions, enough for leaching and translocation of clay. The presence of compound pedofeaturs such as clay and carbonate and Fe and Mn oxides as juxtaposed and superimposed coatings or hypocoatings in paleosols, probably show that these soils are polygenetic. As a conclusion, Naharkhoran loess-paleosol sequence is an indicator for periodic drycool and moist-warm conditions. The loess layers are representative of dry-cool climate, whereas the paleosols are indicators of the moist-warm conditions. Formation of the studied loess and paleosols, have probably taken place in glacial and interglacial cycles with different climatic conditions, respectively.

Nowadays, with regard to economical and environmental aspects of municipal and industrial uses of sewage sludge in agricultural soils has considerable importance in many countries. For purpose of biological sludge effects study on the biochemical properties of Ahar region Haplocambid soil, the experiments accomplished on pots containing 5 kg soil, 7 levels of biological sludge and four replications. The results indicated that with increase of sludge application, number of microorganisms, respiration rate, electrical conductivity, organic matter percent and the percentage of total nitrogen have increased significantly. The application of sludge on amount of soil carbonates and C/N ratio doesn't have significant effects; on the other hand the effect of sludge application on soil pH alterations has shown the decrease of pH in high levels applications in comparison to 20 ton/ha is been significant at 0.05 probability level.

Geostatistical techniques were used to describe and create the map of spatial distribution of saffron weed populations. In 2004-5 growing season, in a saffron (Crocus sativus) field located in Boshrooyeh, Southern Khorasan, Iran, weeds were identified and counted at 144 points of field based on a 4× 4 m grid in 0.3×0.5m fixed micro plots, three interval including prior to post-emergence control, after post-emergence control and at the end of growing season. In the field, 17 weed species were identified. The semi-variogram analysis indicated that 50% to 80.27 % of the variation of sample density was due to spatial dependence, which suggested that most of the species were patchy. Semivariogram parameters did not change significantly over time for Cardaria draba which indicated the relative stability of patches of this weed. Range of influence differed from 1.7 to 45.20 m which depends on weed species and sampling time. Hordeum spontaneum population was affected by postemergence weed control and its spatial correlation decreased from 79.4 to 73.1 percent. The spatial correlation of C. draba and Carduus pycnocephalus increased after post-emergence control. In addition the maps showed elongated patches along the field which may be in response to direction of irrigation and cultivation practices. Patchy weed distribution offers large potential for using sitespecific weed control on our field.

Wild Mustard, a troublesome weed is widely distributed through the canola fields in Golestan province; and there is not any effective way to control Wild mustard, while it can be economically acceptable. Therefore, High competitive Varieties can control Wild mustard effectively. So, a field experiment was conducted at the Research, Breeding and providing of Seedling and Seed of Gorgan Institute, during growing season 2005-2006. The experiment was established as a randomized completely blocks design in a factorial arrangement of treatments with three replications. The seven canola cultivars (Hayola 401, Hayola 330, R.G.S 003, Option500, Sarigol, Zarfam and Talay) were planted in weed-free and weed-infested (with 30 Wild mustard individuals per square meter) Plots. Zarfam and Hayola330 Prouduced the highest yield and Option500 were ranked the lowest in weedy condition. Cultivars were ranked into three groups based on cluster analysis of competition indexes. Zarfam and Option 500 showed the highest and lowest competitive potential with wild mustard respectively. This study showed that Zarfam cultivar having greater LAI, height and better vertical leaf area distribution to prevent yield loss (tolerance) in weed-infest conditions, and more suppression ability in the presence of wild mustard. These criteria used in breeding programs to Screen for more competitive canola cultivars against wild mustard.

In order to determine the effects of water deficit and different nitrogen rates on yield, yield components and physiological traits in rapeseed, a field experiment was conducted using a factorial split-plot in randomized complete block desing in 2005 growing season. In this study, two cultivars (Zarfam and Modena) in three irrigation levels (irrigation after 40, 60 and 80 percent evacuation of soil water) and four nitrogen rates (0,75, 150 and 225 kg/ha) were studied. Results showed that decreasing soil water and nitrogen rate, caused sever stress that caused significant decreasing in yield and yield components, that in this case, decreasing the pods per plant (59.17%) was greater than the other components. Physiological traits like stomatal conductance (68.89%), leaf relative water content (16.37%) and chlorophyll content (29.61%) decreased in water deficit condition, whereas proline content increased significantly, that this increasing was for higher ability of osmotic adjustment in water deficit condition. By increasing nitrogen rate, all of the physiological traits showed significant increasing too. By contrasting the two cultivars, defined that the Zarfam had a higher tolerance to water deficit condition and lower nitrogen consumption, that the reason of these were higher physiological performances such as stomatal conductance, leaf relative water content, chlorophyll and proline in water deficit and nitrogen consumption conditions. Also, this variety had a high potential of production in normal irrigation and high nitrogen consumption.

Yield prediction before harvesting is one of the tools in order to make a plan for food production supply in future. Wheat yield prediction was carried out using different meteorological variables as well as agro meteorological indices in some regions in the western of the country including Sanandaj, Ghorveh, Bijar, Kermanshah and Kangavar for the years 2004-05 & 2005-06. On the basis of the highest correlation coefficients, the lowest standard error of estimate and relative deviation of predicted yield from actual yield using different statistical models, the best subset of agro meteorological indices were selected including daily minimum temperature, accumulated difference of maximum & minimum temperatures, accumulated photothermal units, sunshine hours, growing degree-days, total rainfall and accumulated heliothermal units. The results revealed that in Sanandaj district yield prediction was done using data related to second active vegetative stage of wheat (from 26th of March to 20th of May), for Ghorveh at reproductive stage (from 21st May to 19th of June), for Kermanshah at reproductive stage (from 30th April to 25th of May) and for Kangavar at second active vegetative stage (from 14th of March to 9th of May). In Bijar due to high values of relative deviation none of the models was used. The result showed that in Sanandaj and Ghorveh 68%, Kermanshah 91% and Kangavar 81% of wheat yield variability was accounted for variations in above agro meteorological indices.

This investigation was performed due to canning of Indian shrimp (Penaeus indicus) that have no high export value. For this purpose two sizes of shrimps, medium and small sizes were selected and precooked for canning in three methods: in brine with 6, 9 and 12 percent concentration for 2, 4 and 6 minute, in steam for 5 and 8 minute and deep fat frying for 2 and 4 minute. Shrimps were packed in cans and Canning was made in brine and Oil media. Then organoleptic characteristics of product were investigated with multiple comparison and Hedonic test. Results showed that 2 minutes frying in oil and canning in oil for small sizes shrimp with Hedonic score of total acceptability 6.40, Flavor 6.20, texture 7.00, odour 4, 60 and color 5.00 and 4 minutes frying in oil and canning in oil for medium sizes shrimp with Hedonic score of total acceptability 6.60, flavor 6.60texture 7.00 odour 5.20 and color 5.20 From total 7 score were the best ways for producing canned shrimp. Multiple competition confirmed this results.

Mycotoxins are toxic or carcinogenic secondary metabolites produced by some types of fungi such as aspergillus flavus. The presence of mycotoxins in the food is a result of factors including causative fungi, contaminated products, environmental factors and host. The study was conducted to determine aflatoxin B1 and M1 in the liver, breast and leg muscles of broiler chicks. Forty samples of liver, breast and leg muscles were collected from broiler chicks slaughtered in Ahvaz poultry slaughter house to determine the level of B1 and M1 aflatoxins by HPLC method. The results showed that 37.5% of livers, 22.5% of legs and 22.5% of breast muscles of broiler chicks were contaminated. The highest and lowest levels of contamination were in the liver and breast muscles respectively. Statistical analyses showed that mean aflatoxins B1 and M1 level in the livers of broiler chicks were significantly higher than aflatoxins B1 and M1 in the leg and breast muscles (P<0.01%).

Twenty Sanjabi lambs (33±1.5 kg initial body weight and 3.5 months of age) were used in a completely randomized design to evaluate the effects of feeding yeast (Saccharomyces cerevisiae) on growth, some blood metabolites and carcass characteristics. They were divided into one of two dietary treatments (10 lambs for each treatment). The treatments were: 1) fattening diet without yeast (control group) and 2) fattening diet plus 2 gr/d yeast (Saccharomyces cerevisiae). Lambs were fed experimental diets for 14-d adaptation followed by a 98-d fattening period. Average daily gain significantly (P<0.05) tended to increased when yeast was added to fattening diet. Inclusion of yeast (Saccharomyces cerevisiae) to the diet of fattening lambs significantly (P<0.01) decreased feed conversion rate (FCR) and FCR was improved in yeast lambs. However, the Saccharomyces cerevisiae live yeast did not affect dry matter and organic matter intake. Also, serum glucose and urea concentrations were not significantly different between treatments. Calculated carcass characteristics were also similar for control and yeast groups. These results indicate that under the conditions of this study, the addition of yeast (Saccharomyces cerevisiae) live yeast to diet of fattening lambs increases lambs performance.1

Onion (Allium cepa L.) is one of oldest cultivated plants and is used both for food and medicinal applications. In fact, this common plant is a rich source of several phytonutrients also used in the treatment and prevention of numerous diseases. In this study antibacterial activity of essential oil (EO) extracts of three types of onions (green, yellow, red) against two bacteria, E.coli and S.aureous was investigated. Essential oils were extracted by steam distillation unit, and appropriate volumes of EO-extracts were added to sterile water to obtain desired concentrations. Antimicrobial activity of onions determined with disc diffusion test and conventional tube test. The results indicated that essential oil extracts of three types of onions were effective against s.aureous and E.coli. The former one was more sensitive. Red onion had the highest inhibition and green onion the lowest. The 1, 1.2, 1.4 and 1.8 dilutions that were equal with, 50%, 25%, 12.5% and 6.25% concentrations of essential oils, have bacterial inhibitory growth effect. Taking into consideration results, appear that will be able to utilize natural extracts and separated elements from those, for protecting foods.

Considering the efficiency studies play a role in making available the revise in relative importance, policy reforms and resource management, this study has been accomplished by a sample of 31 survey data from livestock slaughterhouses located in Tehran province and used DEA approach to measure the technical efficiency (TE) and factor effects. Results showed that most of firms are running at half of their capacity. And also, the mean TE of sample was 0.77 which revealed that the present technology can improve the technical performance. On the other hand, the compare means analysis showed a better condition for large scale mechanized and non-public firms. Furthermore, the regression analysis revealed the level of scale, ownership, technology level, age, educational level and proficiency of manager had positive effect and the age of firm had negative effect on technical efficiency. Finally, devolution of public firms to private and cooperative sectors, closing down the old and inefficient firms, as well as establishment of the new firms on the basis of feasibility and site-locating studies suggested to policymakers.

In this study, water absorption behavior of three varieties of rice (Fajr, Neda and Shafagh) was determined at 25, 30, 40, 50, 60 and 70oC by recording the weight increase in grain with respect to time. Physical properties (dimensions, geometric mean diameter, volume and sphericity), bulk density, kernel density and porosity of rice varieties were also evaluated as a function of soaking temperature in the range of 25–70oC. The results showed that the soaking temperature had great effect on the soaking behavior of rice varieties. We found that the water absorption increased when the soaking temperature increased from 25 to 70oC and the soaking time decreased with increase in soaking temperature. There is rapid water uptake initially, which is followed by a slower rate in the later stages and comes to equilibrium or saturation moisture content. Physical properties (dimensions, geometric mean diameter, volume and sphericity) of rice varieties are soaking temperature dependent and relationships between physical properties and their corresponding soaking temperatures were determined. Bulk density, kernel density and porosity of rice varieties changed non linearly with soaking temperature. The bulk density of rice was found to decrease to less value at soaking temperature of 40oC and increase from there to maximum value at soaking temperature of 70oC. The bulk density of Fajr, Neda and Shafagh varieties changed from 732.6 to 768.4, from 720.4 to 777.9 and from 705.6 to 788 kg/m3, respectively. The kernel density of rice was found to increase to maximum value at soaking temperature of 40oC and decrease from there to minimum value at soaking temperature of 70oC. The kernel density of Fajr, Neda and Shafagh varieties changed from 1230.1 to 1245.1, from 1285.1 to 1362.4 and from 1229.7 to 1389.5 kg/m3, respectively. Porosity changes of rice varieties followed a similar pattern during soaking process and after increasing at soaking temperature of 40oC, decreased to minimum value at soaking temperature of 70oC. The porosity of Fajr, Neda and Shafagh varieties changed from 43.3 to 56.1, from 42.7 to 51.6 and from 41.4 to 44.0%, respectively.

Drought is a consequence of fluctuations of climatic conditions. Scientific investigation of drought is essential for water resources planning and management and to mitigate water shortages. Drought analyses were done just by some quality factors during the last few decades, but currently there are several mathematical drought indices. In this research the Standardized Precipitation Index (SPI) was used for analysing and monitoring climatological drought in Golestan Province. For this purpose, monthly rainfall statistical data of 24 gagging stations for 29 years periods were used. The drought status maps were then prepared by using Surfer 8.0 software, for all years. The results showed very high drought fluctuations. Despite finding any clear cycle for drought occurrence, it can be obviously showed that the major drought or wet conditions can occur roughly every 11 years. There can some drought and wet years be observed even during those 11 years. Drought occurrence and frequency was found very high in the border parts of the province and also near the Caspian see beach. These regions are located in dry and semi-dry climate. Moreover, the exact time in which drought begins and ends are not the same in all the regions. Furthermore, there can be at least 3 humidity conditions every year.

Land use planning is a science which determines the optimum uses of land based on ecological charactisics of land and its socio-economic conditions. Case study was Koohdasht basin in Lorestan Province its area 45600ha, maps of different altiude classes, slope percentage, geographical aspect, edaphically properties and vegetation density were combined by overlay method and consequently the final map of environmental unit has been depicted. Climatic characteristics, water resources, road Network and soil erosion for each unit were recorded. Socio-economic studies for the region have been done through questionnaires method. Ultimately, 793 microecosystems were resulted for planning process. Evaluation of ecological capability has been done for agriculture, range management, extensive tourism, and conservation. After combining the result of this evaluation with socio-economic needs of the region, land use planning of Koohdasht has been concluded. The results of planning of Koohdasht, are as follows: 42.6% for agriculture, 17.03% to range management, 3.4% for Forestry, 12.24% for eco-tourism, 0.3% for Urban development and 21.9% to conservation.

Salinization is the whereby the concentration of dissolved salts in water and soil is increased due to natural or human-induced processes. Salinity has been increased in groundwater flow directions and low land area. In this study, hydrogeochemical quality of Incheh wetland in north of Agh-ghala and certain shallow groundwater wells in western part of the incheh wetland with collection of water samples in winter (2005) have been carried out. Hydrogeochemistry results indicate that high salinity of this wetland and shallow groundwaters wells with total dissolved solids more than>1000 mg/l. According to the Gibbs and Chadha diagrams, evaporation is dominant phenomena responsible for the high ionic concentrations found in wetland and shallow ground waters. A high content of Na+ and Cl ions in saline wetland and shallow groundwater wells in comparison with those of river water, suggests a evaporitic origin of wetland and groundwaters. The high positive correlation between of K+ and Na+ indicates that the present evaporitic salts in saline soils are the main source of these ions. On the basis of Piper diagram which shows that the hydrochemical facies in saline wetland is dominated by sodic and chloride (Na+-Cl-) types. The Hydrochemical model reveals that aragonite, dolomite and calcite are saturated while evaporated mineral. Halite in this season is undersaturated.

Bucket spillways are used at the end of high dam spillways due to low cost compare to other types of energy dissipater structures. Impingement of falling jet on the river bed can create scour hole which can cause damage to the spillways, dams body or nearby structures. Accumulation of sediment downstream of scour hole can increase the tailwater and reduce the hydropower generation. Therefore it is important to predict the scour depth when using flip bucket as energy dissipater. The purpose of this study is to conduct experimental tests to understand the mechanism of this phenomenon and to develop relationships for predicting the scour holes dimensions. To reach these goals, at first by dimensional analysis, general relation was developed. The maximum depth of scour holes was found as a function of variable containing discharge, jet thickness, height of falling, particle size and densimetric froude number (SN), which is the ratio of the total active force to the total resistance force acting on a single particle. Then an extensive experimental program was conducted under different size materials and flow conditions. Using the experimental data, different models were examined and the best models were selected. The best models for predicting the maximum scour hole were achieved with variables of discharge, height of falling and particle size. No accurate models were achieved to predict the height of point bar upstream and downstream of scour hole. Finally, these models were tested by applying experimental data from other investigators and it was found that the models presented in this paper can predict the scour depth accurately.

The study of climatologically processes provides the useful tools for basin developers to optimize cost and other facilities of development designs. The aim of this study was to investigate about the relation between large scale climatic signals and rainfall of Khorassan. To achieve this goal, data of 37 rainfall stations were used and they were checked to find out if the rainfall data were randomly collected. In the second stage, mean local time series of rainfall was calculated in Arc GIS software. The meteorological signals of the selected areas were calculated using the local mean seasonal rainfall over the period of Dec to May. Results showed that, there is a very good relation between see surface temperature changes (SST) and see surface temperature gradient (DSST) and 1000 mb with the precipitation of Greenling and Iceland during June to November, Labrador sea during August to November and north of Persian Golf during October to November. It can be concluded that meteorological signals can help us to predict the wet and dry years.

The essential characteristic of river bend is presence of secondary flow. Due to secondary flow, sediment moves away from the outer bank toward the inner bank and therefore the outer bank of river bend is one of the best locations for lateral diversion. The mechanism of flow in a channel bend is much more complex when the outer bank of the bend is used for lateral diversion. The study of flow field at lateral intakes is useful for the engineering engaged in designing such structures. In this paper, a three-dimensional turbulent flow field in a 180 degree channel bend with a lateral intake at position 115 degree was measured by an Acoustic Doppler Velocimeter (ADV). The distribution of time averaged velocity components at various plan and cross sections show that there is a circulation in the outer bank in addition to the main secondary flow. The results also show that the width of dividing stream surface in upper layers is greater than the layers close to the bed and the maximum width occurs below the water surface. The strength of secondary flow in various sections of the bend was also calculated using vortex strength criteria. It was found that the maximum strength of secondary flow occurs at section 45 degree of the bend. However there is another local peak value around section 135 degree. The bed shear stresses in the vicinity of the intake are determined by Reynolds shear stresses. For assessing the calculated bed shear stress, the experiments were also conducted on local scour around lateral intake in clear water condition.

The aim of the present study is to investigate the effect of wind speed, nozzle pressure and field bed slope on soil moisture uniformity in the solid set sprinkler irrigation system. For this purpose, 6 plots of 25´30 m with bed slope varying from 1.3 to 13.4% were selected in Bileh-Savar sprinkler irrigation network located in Mogan. For each plot, water application uniformity tests as well as moisture monitoring were carried out in three replications on different days and at different hours of the day. In each of the tests, water application depth and soil moisture were measured at 121 and 100 spots in each plot, respectively. Nozzle discharge and operating pressure, wind speed, relative humidity, and air temperature were measured throughout each experiment. Based on computations and with regard to the ranges of parameters variations, soil moisture uniformity varied from 64 to 88%. A relationship between sprinkler water uniformity and field bed slop was developed. The sensitivity analysis of the relationship demonstrated that soil moisture uniformity is more sensitive to sprinkler water uniformity than to field bed slope. The sprinkler water uniformity was also presented as a function of the dimensionless numbers of normalized wind speed and sprinkler nozzle pressure. The findings illustrated that sprinkler water uniformity is more sensitive to variations of wind speed than to variations of nozzle operating pressure. Hence, the effect of wind speed in soil water content uniformity is more than bed slope and nozzle pressure parameters. The results also indicated that soil moisture uniformity is greater than the sprinkler water uniformity.

Limitation of available water resources on one hand and vast amount of information availability on modern technologies such as GIS and RS on the other hand would seem to dictate the need for an appropriate irrigation network management. The main objective of this research is establishment of a data bank utilizing the data sources of Doroodzan Dam Irrigation Network (Fars Province), for making improvement on irrigation water management of this network, by using GIS and RS. The results of this research have indicated that an appropriate program for optimal utilization of soil and water resources in irrigation networks requires a data bank so that the linkage between different types of spatial and descriptive information, timely and fast dissemination of data, statistical analysis, and modeling can be provided.

The effect of concentrations of egg yolk (2.5, 5, 7.5, 10, 15 and 20%) in Tris diluent on viability, motility and progressive motility of frozen-thawed Markhoz goat in breeding season was studied. The semen was collected from 5 Markhoz bucks twice a week during 7 weeks. Every time after collecting Fresh semen evaluated for motility and sperm concentration. Semen diluted with Tris-Citric acid- Fructose (TCF) extender containing different concentration egg yolk was cooled to 5oc and then frozen at-80oc in nitrogen vapor and stored it in liquid nitrogen. Thawing was performed by placing the straws in a water bath at 37oC for 30s. The post-thaw viability was 57.48, 60.17, 55.21, 54.91, 53.74 and 49.53% for 2.5, 5, 7.5, 10, 15 and 20% of egg yolk concentration, respectively. The effects of different concentrations of egg yolk on post-thaw motility were as 52.92, 55.71, 50.78, 49.85, 49.21 and 45.35%, respectively. The results for post-thaw progressive motility showed 39.21, 42.28, 37.85, 36, 37 and 32.42% in different concentrations of egg yolk, respectively. Maximum and minimum of viability, motility and progressive motility were obtained in 5 and 20% egg yolk concentration, respectively. The result show a significant decrease in sperm viability and motility by increasing the egg yolk in Tris buffer (P<0.05). Therefore, using 5% of egg yolk concentration in Tris diluent can be suitable for cryopreservation sperm Markhoz goat during breeding season.