JWSS - Journal of Water and Soil Science

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Twenty-two surface soil samples (0-20 cm) from Fars province were extracted by five extractants (i.e., DTPA, 1.5 M NH₄H2PO₄, 0.1 NH₃PO₄, 0.05 MNa2EDTA, and 1% Na₂EDTA) and used in a 7-week greenhouse experiment which was a 22 × 3 factorial with 22 soils (clay 16-63% pH 7.8-8.2 electrical conductivity 0.32-1.78 dS m^-1 calcium carbonate equivalent 28-63% organic matter 1.1-4.9% cation exchange capacity 9-27 cmol kg^-1 and DTPA-extractable Mn 4-24 mgkg^-1), 3 levels of applied Mn (0, 10, 20 mg Mn kg^-1 as manganese sulfate), 3 replications, and soybean [Glycine max (L.) Merr., cv. Williams]. Application of Mn significantly increased top dry weight by 4 to 104%, averaging to about 12% over the control. But the increase in Mn concentration was not significant. Total Mn uptake also significantly increased but the apparent recovery of the applied Mn was very low (i.e., 0.05%). Soil pH, calcium carbonate equivalent, and clay content were found to be the properties influencing the extractability of Mn. The DTPA-extractable Mn, alone (with a critical level of 13 mg Mn kg^-1) or along with some soil properties, was the only form of Mn that could reasonably predict the plant responses.

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To estimate heritability, and genetic and phenotypic relationships and also to study the effect of sex and rearing environment on body weight, weight gain, feed consumption and feed conversion coefficient, the data from 1200 pedigreed male and female chickens from three genetic groups including 90 sires were used. The included genetic groups were crosses of native chickens and an exotic breed (group A), native chickens which were selected for two generations on the basis of 8th week body weight (group B) and a control group of native chickens (group C). All the chicks were reared up to four weeks of age on the ground in separated pens according to their sire groups. In order to calculate feed conversion coefficient, 498 chicks were placed in individual cages during four to ten weeks of age. The results showed that the cross group (A) compared to the other two groups had a higher body weight at 2, 3, 6, 8 and 10 weeks of age. Weight gain, feed conversion coefficient and consumption at periods of 4-6, 6-8, 8-10 and 4-10 weeks were also higher in the cross group. Genetic groups B and C, in spite of better performance of group B for most of the traits, did not have any significant differences for the compared traits. Estimated heritabilities on the basis of sire variance component showed that these traits were medium to highly heritable. Estimated heritabilities for feed consumption at different ages ranged from 0.15 to 0.44 which at any age was lower than that estimated for feed conversion coefficient. Genetic and phenotypic correlations between growth traits were positive and, in most of the cases, high. Correlations between nutritional traits at different ages were variable.

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Limited time for crop residue decomposition and complete seedbed preparation in double-cropping necessitates reduced tillage which is associated with its shortcomings. Information about seedbed preparation aspects in double-cropping of wheat and mungbean in Isfahan is lacking. For this reason, the effects of various seedbed preparation methods on growth, seed yield and yield components of mungbean (experimental line 1-61-16) were studied in a wheat-mungbean double-cropping system during 1996 at the Agricultural Research Station, Isfahan University of Technology. Two residue management treatments (burned and nonburned) along with four tillage systems: moldboard plow, disk, khischee and no-till were laid out in a strip plot design within a randomized complete block design with four replications. Improved establishment and plant growth conditions associated with burning residue treatment significantly increased plant density, above ground plant weight, number of nodes per branch, plant height, number of pods per main stem and per square meter, number of seeds per pod on main stem and on branches, number of seeds per main stem, seed yield, biological yield and harvest index. Higher plant density in this treatment resulted in significant reduction in the number of branches and number of pods per branch. Desirable conditions for establishment and growth in disk and moldboard plow treatments significantly increased plant density, above ground plant weight, number of pods per main stem and per square meter, number of seeds per pod on main stem and on branches, number of seeds per main stem, seed yield, biological yield and harvest index. No-till treatment produced the least results in respect to the above traits. The results indicated that burning residues with disk tillage system might be an appropriate seedbed preparation method under conditions similar to this experiment.

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In vitro salt tolerance of 28 cultivars of durum wheat with native and exotic origins was investigated, using MS medium containing sodium chloride. The resulting calli were subjected to 8 salinity levels including 0, 0.3, 0.6, 0.9, 1.2, 1.5 and 1.8 percent NaCl (w/v). Donor plants of explant (immature embryo) were grown in a recirculating hydroponics and pots in a greenhouse as well as in the field. Assessment of calli was conducted after 0, 8 and 16 days after subculture of calli into the NaCl-contained medium. Callus growth rate, relative callus growth rate and percentages of callus necrosis were measured, using a 8 × 28 factorial experiment layout in a completely randomized design with 3 observations per treatment and 3 replications. Results of analysis of variances showed that among the criteria, relative growth rate of callus was the most reliable, while callus growth rate as not being quantitatively measured, was less devoted. Results of this study revealed that 'PI 40100' and 'Dipper-6' were superior genotypes for in vitro salt tolerance. The high relative callus growth rate and less callus necrosis of these cvs. may indicate their superior genetic potential for in vitro salinity tolerance.

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Studies on sustainable agricultural have not paid adequate attention to farmers' behaviour regarding sustainability. The objectives of this research were: 1) to determine the relationship between socio-economic and farming factors with “sustainable agricultural knowledge”, 2) to predict “sustainable agricultural knowledge” based on socio-economic and farming factors, and 3) to determine the relationship between sustainable agricultural knowledge and sustainability of farming systems. A survey research was used with a multi-stage cluster sampling technique to collect data for the study. In the first stage, 39 villages were selected in Fars Province. Then 200 wheat producers were randomly selected in these villages for interview. The findings indicated that there was a significant and positive correlation between “sustainable agricultural knowledge” with level of literacy, achievement motivation, amount of total wheat production, technical knowledge about wheat production, economic condition, wheat farming model, amount of supervision by Agricultural Service Centers, and educational services provided by extension agents. Stepwise multiple regression indicated that technical knowledge about wheat production, achievement motivation, type of land revenue system, level of literacy and wheat farming model (independent variables) explained more than 50 percent of variability in “sustainable agricultural knowledge”. There was no significant correlation between “sustainable agricultural knowledge” and “sustainability of farming systems”. Possible reasons for this lack of relationship have been discussed. Based on the findings of this study, recommendations are provided towards achieving a more sustainable agricultural system.

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Barley consumption is limited in broiler chicken diet due to their β. glucanas polysaccharide content. The application of synthetic enzymes in poultry diet can increase the barley content. The purpose of this experiment is to study the effect of enzyme supplement-β-glucanas on the performance of broiler chickens, percentage of abdominal fat, intestine weight and economic evaluation of production of one kilogram of meat in diets including different levels of barley and corn. Five hundred forty-one-day-old commercial broiler chickens (Arian) were divided into 45 groups, 12 chickens per group Each one of the 15 experimental diets, in which barley was substituted for corn at levels 0, 25, 50, 75 and 100% with 2 levels of enzymes (0.025 and 0.05%) was fed to 3 groups of chickens for 49 days. All diets were isoenergetic and isonitrogenous. Plant oil was used to make diets isoenergetic. The results showed that the rate of weight increase of broiler chickens decreased as each level of free enzyme barley was replaced at 0.83, 6.08, 12.9, 16.1 %, respectively. The weight gain of the chickens fed with diets including a large amount of barley and 0.05% enzyme didn’t have any significant difference (P < 0.01) with the control group. The chickens fed with diet including barley and 0.025% enzyme didn’t have any significant difference either (except at 75% and 100% barley replacements). Enzyme supplementary at 0.025% and 0.05% levels (especially at 0.05%) caused significant improvement (P < 0.01) in food consumption and feed conversion ratio of chickens fed with diets including barley. Analysing the carcass of these chickens showed that the enzyme used at both levels, especially at 0.05 %, caused a significant decrease (P < 0.01) in abdominal fat (3.62% vs. 4%). It was also seen that the weight of chickens fed with enzyme decreased significantly (P < 0.01) in comparison with chickens fed with free enzyme barley diets (9.57% vs. 14.81 %). The economic calculation results of producing meat in this experiment pointed out that using barley and corn caused reduction in production expenses. The general results of this study showed that barley with enzyme is a suitable replacement for enzyme and further that 0.05% level of enzyme is better than 0.025% level due to its performance and better economic results.

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In spite of different reports about the inheritance of cotyledon colour in lentil, the precise nature of this phenomenon is unknown. In a comprehensive study, conducted in 1993-96 on inheritance of morphological markers in lentil, two types of green colour, light green and dark-green lentils, were distinguished for the first time. The dark-green showed monogenic and the light-green showed digenic inheritance. To explain this, involvement of three genes, Dg, Y and B in the inheritance of cotyledon colour were considered. At the dominant state of gene Dg, the genes Y and B produce yellow and brown pigments, respectively. At the recessive state (dg dg), no pigment will be produced and the dark-green colour will appear. If gene Dg acts normally (dominant state), but both genes Y and B are at recessive state (Dg-yybb), again no pigment will be produced and cotyledons will be of light-green colour.

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Stickiness and pastiness after cooking is one of the basic problems of macaroni production technology. Investigation of the factors affecting stickiness and pastiness of Iranian Macaroni is essential. The purpose of this research was to study the effects of percentage of gluten in the flour as well as extruder and drying temperatures on the macaroni quality. The factors studied are as follows:

1- Percentages of flour gluten at levels of 8.5, 10.5, 12.5 and 14.5 prepared by adding gluten to the macaroni flour purchased from the market.

2- Temperature of the dough discharged from the extruder (three levels: 48, 58 and 68 °C) obtained through changing the temperature of the water used in making the dough, circulation and noncirculation water in extruder jacket, and changing the rotational speed of extruder screw and increasing dough retention time.

3- Drying temperature (two levels: 50 and 62 °C) obtained through changing the number of burners in the heating system and using electrical heaters in the drying cabinet.

 The results of the e:xperiments and their evaluation are as follows: using flour with a gluten percentage of 12.5 or 14.5 (12.5% gluten is preferred for economic reasons) with an extruder temperature of 48 °C and a drying temperature of 62 °C will improve the macaroni quality. This treatment resulted in the production of macaroni with less stickiness, pastiness and cooking loss.

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Variability of seed storage protein electrophoretic patterns revealed by SDS-Polyacrylamide gel electrophoresis and their possible relations with some morphological and phenological characteristics were studied using 193 accessions from Iran Mungbean (Vigna radiata L. Wilczek) Collection. Seed protein electrophoresis revealed six different patterns that were different in two albumin and four globulin subunits with molecular weights of 23500-34000. Pattern types 1 and 2 had a considerable frequency but pattern types 3, 4, 5 and 6 had low frequencies and probably had developed recently in mungbean evolution process. Cluster analysis of countries and cities using the frequencies of albumin and globulin subunits showed no relation between geographical diversity and similarity distances. The correlations of morphological traits and albumin and globulin subunits indicated a relationship between G1 and G2 subunits with 1000 seed weight and days to beginning of maturity. Therefore, selection based on protein patterns at preliminary stages of breeding programs might be effective in increasing seed yield together with earliness.

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Estimation of flood flow rate represents a method of preventing damages associated with this natural phenomenon. This estimation is one basis in the design of various hydraulic structures, dam spillways, watershed management and flood control. The maximum flow rate of floods is determined by methods such as Creager, Jarvis-Meyer, Cypress-Creek, and rational method. Rational-probability method is an alternative to estimate peak flood rates, and is expressed as:

 Q(y) = F. C(y). I(tc.y).A

 where Q is maximum flood flow rate (m³/sec) y is the return period (year) C(y) is runoff coefficient with a return period of y A is watershed area (km²) I is rainfall intensity (mm/hr) for a specified return period equal to time of concentration of the watershed and F is the conversion factor equal to 0.278 when the above units are used. The basic concept of this method is the same as that in the rational method except that the return period is also included in the equation. Usually, runoff coefficient, C(y), is determined empirically from tables cited in the literature (e.g., Chow et al., 1988). In the present research, data from 18 hydrometry and 6 rainfall-recording stations (located in Caspian - Sea watershed) were analysed using TR software. The Caspian - Sea watershed (which covers eastern and centeral parts of Iran's No. 1 main watershed) has the sub-basins of Atrak, Tadjan, Chalus, Sardabrood, Siahrood, Gorganrood, Safarood, Kesilian, Babolrood and Neka. Runoff coefficients with return periods of 2, 5, 10, 25, 50 and 100 years were determined for these sub-basins and iso-coefficient curves were plotted. The results showed that computed runoff coefficients were less than the values given in the literature because they are determined from observed flow rate and rainfall intensity in each catchment. It was also shown that runoff coefficient increased with increasing return periods. Application of the computed runoff coefficients in three sub-basins of the area resulted in more accurate estimations of maximum flood rate than when the values for these coefficients cited in the literature were applied.

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This study was conducted to evaluate the capability of reversed-phase high performance liquid chromatography (RP-HPLC) of wheat (Triticum aestivum L.) storage proteins, and their genetic variability in different winter and spring isolines, cultivars and landraces. Gliadin proteins were extracted from the flour of five randomly selected seeds of each genotype. In this method, Nucleosil C18 300 A column (250×4.6 mm ID), equipped with a guard column and acetonitrile containing TFA as mobile phase was used.

All selected conditions for RP-HPLC such as suitable velocity and resolution were sufficient to achieve the objectives of this study. Under these conditions, the number of gliadin components by RP-HPLC analysis was more than electrophoresis subunits. In addition, quantitative results of RP-HPLC facilitated the data analysis. Also gliadin analysis by RP-HPLC had a high potential in detecting rye (Secale cereale L.) genes, so that the presence of ω-secalins in the genome of Falat variety was easily detected. Therefore, it was concluded that RP-HPLC analysis of gliadin proteins is as efficient as electrophoresis, and could even replace it in some cases. The result of cluster analysis for gliadin polypeptides indicated the gradual increase of genetic variation from isolines to landraces. Generally speaking, among the landraces, Ali Abad, Aghda, Sefid Bafghi, Ghermez Bafghi, Shahdas and Sorkheh had greater genetic variations.

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Designers of hydraulic structures are often faced with the problem of estimating flood frequencies at stream sites, where little or no flow information is available. A regional regression model is widely used which relates physical and climatological parameters to flow characteristics. In this study, a new method is used which is based on the station-year technique and combined records for several stream-flow gaging stations to make a single composite sample. This method, named ‘hybrid’, was proposed by Hjalmarson and Thomas (1992). It was applied to a group of records from 17 apparently homogeneous stream gaging stations to determine regional flood frequency equations. The study area consists of two adjacent basins, Gavkhoony and North Karoon in the central part of Iran. Using area and mean elevation of the catchments as the most important criteria in relation to peak discharge, the interactive process of the hybrid method was performed, resulting in two-parameter models of regional flood frequency. The performance of the hybrid method was evaluated by comparison with the regional relations determined from a multivariate regression. The comparison revealed that the accuracy of the hybrid method was significantly better than the regression method for low return periods.

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An experiment was carried out to study the effect of different levels (3.06, 3.23, 3.4, 3.57 and 3.74%) of calcium and vitamin D₃ supplementation (2000, 2200 and 2400 IU/kg diet) on the performance of laying hens. In a completely randomized design and in a 5 × 3 (15 treatments) factorial arrangement, two hundred and forty (240) white leghorn laying hens strain Hy-Line W 36, 26 weeks old, were divided into 60 replicates, four hens per replicate. The experimental period lasted 90 days, until the hens reached 38 weeks of age. The results indicated that calcium levels did not have any significant effects on the percentage of egg production, feed consumption, feed conversion ratio and egg mass. Egg weight significantly (P < 0.05) increased at 3.4% Ca level. Vitamin D₃ had no significant (P < 0.05) effects on egg weight, feed consumption and egg mass, but feed conversion ratio significantly (P < 0.05) decreased and percentage of egg production raised significantly (P < 0.05) due to added vitamin D₃. Interaction between vitamin D₃and calcium on egg weight and egg production was significant (P < 0.05). The regression equations indicated that performance traits can be estimated from calcium and vitamin D₃levels in diet.

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The purpose of this research is to determine the application efficiency of rice irrigation plots and to analyze the reasons for low efficiency. The study will also try to determine the effective factors which could increase the application efficiency of rice fields. The selection of rice fields was based on climate, soil characteristics, and farmer management. Water application efficiency was determined by field measurements in three modern irrigation networks named Fouman (F), Rasht (G) and Lahidjan (D). In the meantime, a traditional network was included for comparison. In the study areas, the soil texture was heavy with an infiltration rate of less than 3 mm/day. The study was carried out under two different conditions: (1) without return flow and (2) with return flow. In the first case, the average application efficiencies in Fouman (F), Rasht (G) and Lahidjan (D) were about 51.2, 49.0 and 49.4 percent, respectively and the maximum and minimum values were about ((52.6, 49.7)), ((50.7 , 47.3)), and ((50.7 , 48.0)) percent, respectively. In the second case, the average application efficiencies for the above-mentioned regions increased to 73.4, 73.3 and 72.4 percent, respectively and the maximum and minimum values were about ((74.3, 72.4)), ((74.3, 72.1)), and ((73.0, 71.5)) percent, respectively. Runoff ratios in the above-mentioned regions were 30, 33 and 31 percent, respectively. During growing period (from transplanting to harvesting), the average applied irrigation water was about 1130 mm (11300 m³/ha) and the average evapotranspiration was determined to he about 561mm.

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Feed shortage is one of the most important characteristics of Iranian livestock industry. Therefore, the utilization of agricultural by-products in animal nutrition, especially for fattening animals, is of great importance. In order to study the effect of the four rations containing various levels of tallow (0, 2.5, 5, and 7.5%), on the performance of male Holstein calves (MHC), responding to the above treatments 1, 2, 3 and 4, twenty four MHC (191±32.1 kg) at age 6-7 months-old in a completely randomized design were used. The calves were fed individually for 195 days ad libitum.

Average daily gains (ADG) of the MHC fed diets 1, 2, 3 and 4 were 1.56, 1.61, 1.69 and 1.75 kg (P<0.05), respectively. Feed conversions (as DM) were 4.63, 4.31, 41.2 and 3.98 (P<0.05), respectively. Added tallow to the ration did not affect carcass, empty body weight (EBW), but increased warm carcass weight (P<0.05). The dietary treatments did not increase digestibility (D) of dry matter organic matter, crude protein and gross energy either, but decreased D of neutral detergent fiber and increased apparent crude fat (P<0.05).

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Field capacity (FC) and permanent wilting point (PWP) are important factors affecting irrigation scheduling and field management. FC and PWP can be estimated from some of the soil physical and chemical properties. Pressure Plate apparatus is usually used for determination of FC and PWP, but this is a time-consuming and laborious procedure besides, the apparatus may not be available in many laboratories. Samples were taken from 23 locations in Isfahan and Chaharmahal Va Bakhtiary provinces in central Iran. Soil texture, organic matter and cation exchange capacity were determined. Soil moisture at FC and PWP of the soils were measured with a pressure plate. Simple and multiple regression analyses were used to study the relationships between FC and PWP with sand, silt, clay, soil organic matter and cation exchange capacity.

 Results indicated that FC significantly correlated with sand, organic matter and cation exchange capacity in a stepwise model (r=0.97**). The PWP of soil also correlated significantly with silt, organic matter, and cation exchange capacity in a stepwise model (r=0.95**). Available water capacity (FC-PWP) correlated with sand in a stepwise model (r=0.82**). On the whole, results showed that FC and PWP can be estimated from some soil physical and chemical properties.

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Successful implementation of socio-economic projects depends on the degree of planners’ awareness of farmers’ risk coefficient. Because agriculture is a risky activity, knowledge about the farmers’ attitudes toward risk in each area is essential. This research investigated the farmers’ risk behavior in Homayjan district in Sepidan township. Cross-section and time series data were collected from a random sample of farmers and from Agricultural Department of Fars Province, respectively. In this study, the Safety First Rule (SFR), Generalized Stochastic Production Function (GSPF) and Target Motad models were used.

The results indicated that in this area, farmers are risk averse in crop production, but they have a low risk coefficient in the use of modern inputs. Signs of GSPF revealed that the use of modern resource input reduces risk. Target Motad risk programming model confirmed that farmers are risk averse because with increasing risk, crops like wheat that have relatively stable prices and yield enter the model, while crops like onion that have high instability in price and yield are omitted from the model.

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An experiment with 720 pullets was conducted to investigate the effect of dietary energy levels of pullet and dietary energy and fat of laying ration on subsequent performance parameters during 14-20 and 22-44 weeks of age. In the first period, white leghorn pullets were fed with two diets of low and high density energy (2600 and 3200 Kcal ME/kg). In the lating period (second period), birds, in each treatment of pullet period, were fed with six diets containing three levels of low, medium and high energy (2600, 2750 and 2900 kcal/kg) at two levels of supplemental fat (zero and 2%). All diets were formulated to meet minimum NRC (1994) requirements of amino acids and protein. This experiment was done in randomized complete block designs with 5 replicates. The levels of energy in the growing period did not affect egg production, egg weight, daily feed intake, feed conversion rate and age of pubertal maturity in laying period, but pullets fed with high energy diet had significantly higher weights as compared to low energy diet in the beginning of laying period. In the laying period, the use of supplemental fat (2%) improved egg production and egg weight, but feed intake and feed conversion rate were not affected. Means of feed conversion rate, feed intake and egg production during laying period in low energy diet were greater than those as compared to high energy diet, but egg weight was not affected by energy level of diets. Low energy intake to protein intake ratio in low energy diet versus high energy diet may be a reason for greater egg production in lower energy than in higher energy diets.

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Peak discharge is one of the basic parameters in the design of hydraulic structures. There are various methods for peak discharge determination. Regional flood frequency analysis is based on physical, climatological and hydrological characteristics of basins. The objective of this study is to examine different models for the estimation of quantiles for some catchments in western Iran (namely: Gharehsoo, Gamasiab, Kashkan, Seimareh, Sezar and Abshineh) for which only maximum daily mean discharge data exist. In this research, peak and maximum daily mean discharges for 11 stream gauging stations were collected for a 21-year period. The ratio of these two discharges (R) and mean and standard deviations of peak discharges and maximum daily mean discharges were computed. Catchment characteristics including catchment area, catchment perimeter, main channel length, mean elevation, mean slope equivalent rectangle length, circular ratio, Gravelius coefficient, drainage density, time of concentration, relief ratio and diameter of the circle having equal area with the catchment were computed. Linear regression analysis was performed between independent variables of the catchments and mean standard deviation of the parameter “R” to develop a relation. The results of this study can be applied to the estimation of extreme flow values for non-recording stream gauging stations (daily reading sites).

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The application of “Modified Einstein Procedure” is recommended by the Specialized Committee on Sediment, Iranian Ministry of Energy. However, this method has not been applied to any river in the country. It is the purpose of this study to investigate the total sediment load of the Karun and Karkheh rivers at Ahwas and Hamidieh stations.

The graphical calculations of the method are very complicated and time consuming. Therefore, a mathematical model has been developed in this study to improve the accuracy, simplicity and speed of computations. The required data were obtained from the above stations for seven years (1988-95), and applying these data, the total sediment load was calculated using the model. The bed load for the above stations was also computed and the ratio of bed load to total sediment load was calculated. In addition, measured data from East Fork river (in USA) were applied to examine the accuracy of the method in estimating the bed load. Comparison of the measured and computed results shows that the “Modified Einstein Procedure” estimates the amount of bed load with a high accuracy. The relationship between the bed load and suspended load and also between the total load and the stream discharge have also been established.

Finally, it is concluded that the “Modified Einstein Procedure” with minor modifications can be successfully applied for the above-mentioned rivers of Karun and Karkheh.