JWSS - Journal of Water and Soil Science

---

Rice bran is the most important by-product of rice milling. It is a valuable source of edible oil in most rice producing countries. Rice bran oil is used in babyfood, biscuit, poultry, fish and farm animal feeds. The storage of rice bran without 'heat processing will result in hydrolysis and auto-oxidation of lipids, and to its decreased physicochemical, organoleptic and nutritional quality. Rice bran is rich in carbohydrates, free amino acids, lipids and different enzymes. The enzymes have destructive effects on the quality of rice bran components. Heat processing is an effective method to reduce the microbial and enzymatic activity of bran. This study was carried out using a factorial experiment by completely randomized design with three replications to investigate the effect of heat treatment and storage time on rice bran crude oil properties.

The parboiling treatment was effective on the rice kernel strength. The bran produced from parboiled rice milling had lower endosperm components. This type of bran had a lower starch but a higher oil percentage. The results of color of rice bran oil samples determined by Lovibond showed that the oil from parboiled rice bran before and during storage had better color than the other samples. Iodine value of bran oil from parboiled paddy decreased during the storage period. The results from studies on fatty acid composition of oil samples determined by gas chromatography (G.C.) showed that the quantitative trend of fatty acids of the control sample remained the same as that in the rice bran samples with the treatment process.

---

Phosphate sorption by soils is one of the most important processes indicating the buffering power and availability of P for plants. Phosphorus sorption characteristics of eight representative calcareous soil of Isfahan region were evaluated. For this purpose, 3 grams, of < 2-mm soil were equilibrated for 24 hours at 25±l °C in 60 ml of 0.01 M CaCl₂ with varying amounts of P. Sorbed phosphorus was calculated by the difference between P initially added and P remaining in the final solution. Langmuir, Freundlich, Temkin and Van Huay equations were fitted to the sorption data.

 All four equations adequately described the relationship between sorbed and solution P, but the Van Huay model was slightly superior. Some phosphorus buffering indices were calculated from the sorption isotherms. These buffering indices were highly related to each other as well as to soil properties. Clay percent showed the highest correlation with buffering indices (r=0.771 to 0.949) followed by calcium carbonate equivalent (CCE) and cation exchange capacity (CEC). The quantity of P sorbed at standard concentration of 0.3 µg P/ml (SPR) is reported to the amount that satisfies the phosphate requirement of many crops. This parameter was calculated from Van Huay equation and showed a strong correlation with buffering indices (r=0.807 to 0.990) and soil properties such as clay (r=0.960) and CCE (r=0.809) percents. Regression analysis suggested that clay and CCE percents were the most important soil properties for estimating the buffering power and the standard P requirement of the calcareous soil in Isfahan region.

---

Iran, as the biggest producer of dates, has 25 percent of the world date production. More than 400 varieties of dates have been identified in Iran. Dates have a high nutritional value they contain considerable amounts of sugar, vitamins and minerals. For instance, 2830 kilocalories of energy are obtained from one kilogram of dates. Dates are economically suitable replacements for sugar in bee feeds. However, feeding bees with some varieties, which contain certain amounts of mannose and potassium, are harmful. This investigation was carried out in order to identify the most suitable variety of dates useful for bee feed and to determine its nutritional value as human food. In this study, the dominant varieties of date including Bam Mazafati, Behbahan Kabkab, Booshehr Kabkab, Jiroft Mazafati, Kangoroad, Khanizi, Khasi, Saameran, Shahani, Shahdadi and Zahedi, were collected and analysed. The amounts of moisture, fat, protein, ash, and minerals such as sodium, potassium, and calcium were determined. Also, sugar composition of the above varieties consisting of glucose, fructose and sucrose, was measured. Chemical methods (Lane-Eynon and Shaffer-Somogyi) and high performance liquid chromatography were used for sugar determination.

The results showed that, except for moisture and protein contents, there was no significant difference between fat and ash contents of the samples. Shahdadi and Zahedi had the highest and lowest moisture contents, respectively. Behbahan Kabkab and Shahdadi had the highest and lowest protein contents respectively. Jiroft Mazafati and Saameran had significantly the lowest amounts of potassium and mannose, respectively, while Kangoroad had significantly the highest amount of sucrose, which is use full for bees. Therefore, these three varieties were found to be suitable replacements for sugar in bee feeds, but considering their price, Saameran is recommended as the best feed for bees. On the other hand, with respect to the minerals and sugar contents, Behbahan Kabkab was found as the most nutritious date for human food.

---

During the summer of 1998, leaf and pod blight symptoms of bean were observed in Arak, The survey in the following year showed that the disease had an increasing trend in bean-growing regions of Markazi Province. It appeared that more severe losses occurred in fields equipped with sprinkler irrigation system. Symptoms of diseased plants consisted of formation of irregular necrotic lesions on leaves surrounded by yellow halo. Under favourable conditions, these lesions gradually expanded and heavily infected leaves became blighted. The primary symptoms on infected pods were the development of water soaked spots which later turned to dark or reddish blotches. In attempts to investigate the causal agent, two types of a Gram negative bacteria with raised, yellow and translucent colonies were isolated from leaves and pods of blighted beans. All strains produced Xanthomonadin pigment and their inoculation on young bean plants induced disease symptoms similar to those observed under field conditions. Based on morphological, physiological and biochemical properties, the predominant pathogenic type was identified as Xanthomonas axonopodis pv. phaseoli. However, the other strain with the same properties, but capable of producing melanin pigment in nutrient media, was assigned to X. axonopodis pv. phaseoli var. fuscans.

---

This paper studies the structure of cost and production of rice using cross section data from rice farming in Guilan in 1997. A translog cost function is specified for this purpose and estimated, using Iterative Seemingly Unrelated Regressions for both the short and the long run where all factors are taken to be variables. The results of the study are as follows:

1. Neither in the short-run nor in the long-run is the possibility of technical substitution among the factors of production strong.

2. Own and cross price elasticity of demand for inputs are positive but less than one, hence limited substitutability among inputs is possible as the result of a change in input prices.

3. As the structure of production of rice in Guilan exhibits increasing returns to scale, increased allocation of land to the production of rice could result in a lower price of the product.

4. Inputs are not homogeneous, therefore, not all producers are faced with the same price for the same input. Nevertheless, the cost of production has been lower for those farmers who have paid a higher price for an input. Therefore, the higher price for inputs is more than that compensated by the quality of each input in the production process.

5. Due to the inelasticity of the demand for rice with respect to prices, a large price increase is required to stimulate farmers to allocate more resources to the production of rice.

6. Since the possibility of substitution among inputs is limited, a large increase in relative prices is required in order to change the structure of rice production.

---

A Complete Randomized Block design was used to study the total protein efficiency (TPE) in Iranian Kilka and Peruvian Anchovy fish meals. Six isoenergetic (3200 kcal ME/kg) and isonitrogenous (18.5% CP) diets based on corn with six samples of fish meal (No. 1, 5, 6 steam processed, 2, 4 flame processed Kilka fish meal and No. 3 Peruvian Anchovy fish meal) were formulated and fed to Lohman male chicks from 7 to 42 days of age. Feed consumption and weight gain were measured weekly. Total protein efficiency and feed conversion (FC) were calculated and statistically analyzed.

The highest TPE values in fish meals obtained over the period of 7-28 days and significantly differed (P< 5%) among Kilka and Peruvian fish meals. With the exception of sample No. 5, the highest values of TPE obtained in the case of steam processed and the lowest obtained the case of flame processed Kilka fish meals. The TPE value of Peruvian fish meal was approximately equal to the average of the two types of processed Kilka fish meals. The orthogonal and nonorthogonal comparison of TPE and feed conversion (FC) in Kilka fish meals, regardless of the type of processing, with the same values in Peruvian Anchovy fish meal did not show any significant differences (P> 5%). With the exception of sample No. 5, the highest final weight of chicks obtained with steam processed Kilka fish meal. In general, TPE values in Kilka fish meals were variable when compared to Peruvian fish meal and TPE of steam processed Kilka fish meal was better.

---

Many sediment transport equations have been developed for estimation of the river sediment materials during the past four decades. There are significant differences in the results from these equations when applied to compute sediment transport for a specific river. Therefore, application of an equation for estimation of a river sediment load is not an easy task. In this study, 12 important sediment transport equations including Meyer-Peter and Muller, Einstein, Bagnold, Engelund and Hansen. Toffaleti, Ackers and White, Yang, Van Rijn, Wiuff, Samaga et al, Beg and Fazel were tested against the measured field data of four major Khuzestan rivers, namely, the Karoon, the Dez, the Karkheh, and the Maroon. For accurate results and rapid computation, a computer program was developed for this purpose. Over 490 measured data from the gauging stations of these rivers are selected. Using these data, the hydraulic parameters and the bed material of the gauging stations are determined.

The results of the computer program are analyzed and compared with the measured data. The results from this study show that those equations which are based on the energy exchange of the flow, are generally in good agreement with the measured data for Khuzestan Rivers. From these equations, the Engelund and Hansen’s equation generally predicts satisfactory results for the all gauging stations except for the Maroon River gauging station. And finally if the sediment load computed by the Beg’s method is multiplied by a factor of 0.1, the results approximately match those obtained from the Engelund and Hansen’s method.

---

This manuscript shows the findings of a research that investigated the effects of trainings on the members and the employees of the poultry cooperatives in Tehran Province on the performance of these cooperatives. To analyze the data, 2, correlation coefficient, one way-analysis of variance, and Duncan Test were used. The results of the study showed a positive and statistically significant relationship between training of members and performance of cooperatives. The more the trainings were related to type of occupation or responsibility, the larger were the effects on the cooperative performance. Cooperatives with more specialized top managers, offered more training to their members. Compared to cooperatives with more training, the members had less participation in increasing their investment.

---

The effect of different media including the growth regulators on somatic embryogenesis from Mexican lime was studied. The average embryo formation after 60 days from unfertilized ovules in different media was evaluated at 0 to 33.75%. The most effective hormone to stimulate embryogenesis was GA₃ at 0.01 and 0.1 mg/l concentrations. Malt extract (ME) at 300 mg/l increased embryo formation, whereas at 1000 mg/l, it inhibited embryogenesis but produced embryogenic callus. Banzyl adenine (BA) at 0.1 and 0.01 mg/l concentrations had significant effects on embryogenesis, while embryo formation was inhibited at high concentrations. Embryo development in different media was also studied. The index of mean root length to mean stem length in the MT³ medium supplemented with 0.1 mg/l of GA₃ was observed to be 1.22±0.22, which was regarded a suitable medium for embryo formation, embryo development and plantlet regeneration.

---

The variation and path coefficient analysis of bread-making quality traits have been studied for 145 genotypes of breeding lines, cultivars and landrace varieties of wheat (Triticum aestivum L.). Bread-making quality traits of genotypes was evaluated indirectly by protein percentage, SDS and Zeleny sedimentation tests, hardness index, test weight, bread volume, grain moisture, and water absorption percentage. Hardness index, Zeleny and SDS sedimentation tests had the highest coefficient of variability (13.51%, 11.83% and 11.03%, respectively). Factor analysis for the genotypes, based on qualitative traits revealed two factors, which explain 98.23% of total variation and were named grain protein index and bread volume factors. The result of correlation analysis indicated positive and significant relationship between protein percentage, SDS sedimentation test and other bread-making quality traits. On the first and second steps of stepwise regression analysis, protein percentage was the most effective trait in explaining different qualitative trait variations. Path analysis also showed the direct and significant effects of protein percentage, Zeleny sedimentation volume, grain moisture and water absorption percentage, and bread volume on SDS sedimentation test. According to cluster analysis based on qualitative traits, the cultivars and landrace varieties, from the view poit of protein quality and quantity, had the highest potential among other groups (generally breading lines).

---

An experiment was conducted to determine growth and carcass characteristics of male broilers subjected to early feed restriction. Restricted birds were fed equivalent to 1/5*BW^0.67 Kcal/day/bird between days 7 and 14. On days 0 to 7 and 14 to 56, all chickens received feed ad-libitum. Diets of feed-restricted birds were supplemented with 15% higher methionin and cystine recommended by NRC (1994) during refeeding in starter and grower periods. No significant differences were observed for liver, breast, heart, carcass and liver fat between early restricted birds and ad-libitum control at 56 days of age. Body weight for restricted broilers were significantly (P<0.05) lower than that of controls in 56 days. However, restricted broilers had significantly lower total-feed to gain ratio than the unrestricted control. Restricted broilers that received diets high in total sulfur amino acids in starter and grower periods had singnificantly lower abdominal fat pad than control birds.

---

To increase mechanized cotton planting in areas with saline irrigation water and crust forming soil in Isfahan Province, assessment of seeders in flatland planting method with or without crust breaking is essential. An experiment was conducted at the Kabootarabad Research Station of Isfahan Research Center to compare the performance parameters of planting equipment in a clay loam soil. Four planting equipment treatments using Bazrsazan and John Deere planters and Nordsten drill along with three crust breaking methods, including rolling cultivator, rolling-type crust breaker and no crust breaking, were laid out in a factorial experiment within a randomized complete block design with three replications. Planters’ performance was evaluated by measuring the number of plants and plant spacings in each treatment, and estimation of the mean and standard deviation, multiples index, miss index, quality of feed index, precision, and hill-dropping index. Although the plant spacings, and not the seed spacings, were measured in this experiment, the indices used in this research showed the planters’ performance to be very satisfactory. The suggested hill-dropping index showed the multiple seeds dropping characteristics of the seeders to be better than those of the multiples index regardless of the crust breaking methods. In the non-crust breaking method, the multiple seeds dropping tendency of Bazrsazan planter brought about a reduction in the mean and standard deviation of plant spacings. Crost breaking caused a reduction in plant spacings for all seeders, especially for the drill whose multiple seeds dropping tendency was negligible. The results indicated that the seed metering systems in Bazrsazan and John Deere planters were volumetric rather than single seed metering devices.

---

In order to increase ketocarotenoid astaxanthin production by Haematococcus pluvialis, the effects of salinity, phosphate deprivation and eosin on growth and astaxanhin production were examined. The experiments were carried out in the growth chamber at 20^oC under sterile conditions. The results showed that under salinity, phosphate deprivation and eosin supply, encystment was induced, and at the same time, astaxanthin formation and dry weight increased. Furthermore, by adding histidine to culture medium as a quencher of singlet oxygen, astaxanthin production significantly reduced. Therefore, it can be claimed that accumulation of astaxanthin may be related to antioxidative responses, which increased survival of algal cells under environmental stress conditions.

---

Side weirs as flow diversion devices are widely used in irrigation, land drainage and urban sewage systems. In the present study, the effects of the length and height of inclined side weir crest on discharge coefficient were investigated in prismatic and nonprismatic rectangular channels.. In this study, 675 laboratory tests were conducted. Analysis of experimental tests showed that the discharge coefficient is strongly correlated with uptream Froude number, height of weir to depth ratio at upstream of weir, ratio of water depth on weir to length of weir, and with prismatic factor. Based on experimental results, a model is proposed. The model is capable of estimating the discharge coefficient under subcritical flow conditions. Finally, the data from the proposed model was compared with those obtained by other researchers under different side and bed slopes. There was a good agreement with a relative error of less than ten percent.

---

During 1998-99, a field experiment was conducted to investigate the effects of residual Processed Municipal Waste Leachate (PMWL) on growth and yield of wheat (variety Roshan). The treatments consisted of residual amounts of 0, 150, 300 and 600 t/ha of PMWL and a residual N, P, K, and Zn fertilizer treatment in a randomized block design with 3 replications. In 1998, rice seedlings were transferred to 34 m plots. After harvesting the rice, wheat was seeded in the same plots without any new treatment. Processed municipal waste leachate and fertilizers were applied during the rice growth. Residual effects of PMWL increased the amounts of available macro- (N, P and K) and micronutrients (Fe, Cu, Zn and Mn) in soil which, in turn, promoted the grain and straw yield of wheat compared to the control. Straw and grain yield increased from 1.67 and 3.50 t/ha in control to 3.93 and 12.80 t/ha in 600 t/ha of PMWL, respectively. The residual effects of PMWL had no significant effect on heavy metals concentrations in plant. The effects of residual PMWL in the soil were proportional to the amount of leachate applied. However, more investigations are recommended to fully understand heavy metals effects on soil, plant, and environment.

---

Soil organic matter and clay minerals adsorb and immobilize extracellular enzymes of microorganisms and increase soil enzymes stability. This study aims to clarify the relative importance of soil organic matter and clay minerals on the cellulolytic activities of soils. Fluca prepared cellulase was immobilized on some agricultural residues and clay minerals, avicel and a sample of soil. Immobilized exoglucanase and endoglucanase were assayed at different times. Activities of the immobilized enzymes were strikingly dependent on the kind of sorbent. After 20 days of storing in refrigerator at 4^oC, the deactivation of immobilized enzymes on the organic substances (as avicel) was very low but deactivation of immobilized enzymes on the soil and clay minerals was relatively high. On the other hand, the activities of immobilized enzymes on the agricultural residues and avicel were significantly higher than the soil and clay minerals. So it may be concluded that a large part of cellulolytic activity of soil is related to immobilized enzymes on agricultural residues. Coating of the clay minerals, soil and avicel with 4 mmol of Al (OH) x per mg of them significantly increased their immobilization capacity and activities of immobilized enzymes. Activities of immobilized exoglucanase and endoglucanase on the Ca- homoionized soil and clay minerals were significantly higher than the K- homoionized soil and clay minerals. However, these effects may be related to the specific effects of cations on the method of enzyme assay or enzymes activities. These homoionizing-cations effects on the activity of immobilized enzymes on avicel were not significant.

---

Evaluation of uric acid contents of poultry excreta was examined for use in the estimation of apparent protein digestibility. Uric acid was determined either by high-performance liquid chromatography or by spectrophotometric method. A high-pressure liquid chromatographic assay was used with absorbance measured at 285 nm. The method used a reverse-phase system with a C18-bonded column (250*4.6 mm, i.d.). The mobile phase was distilled deionized water. Injection volume was 20 l with a flow rate of 1 ml/min. Correlation (r) between the two methods for uric acid content of excreta from birds fed diets with different methionine levels was 0.976. The uric acid values were then used to determine apparent protein digestibility. The apparent protein digestibility values, when corrected for uric acid nitrogen, were comparable with those calculated from amino acid analysis.

---

Due to the need for new fumigants to control insects that attack food commodities, the toxicity of acetone was determined on some species of stored pest insects in Urmia University in the year 2000. In empty space tests, the LC₅₀ values of acetone for Oryzaephilus surinamensis (L.), Callosobruchus maculatus (F.), Tribolium confusum (Duv.) and Sitophilus granarius (L.) were 15.40, 15.51, 17.55 and 18.26 μl/liter, respectively. The experiments of acetone penetration to wheat mass revealed that the application of acetone in headspace led to the penetration of acetone vapours into the wheat mass and killing the S. granarius and T. confusum had been concealed in interkernel space. The comparison of LC₅₀ values of empty space tests with LC₅₀ values of penetration experiments revealed that the increase in penetration toxicity was 8.63 fold for S. granarius. A similar trend was observed for T. confusum adults. In hidden infestation tests, the application of acetone to the headspace resulted in destroying the developmental stages of S. granarius concealed in wheat and achieved 75% mortality at a dose of 160 μl/liter during seven weeks. Acetone showed no deleterious effects on the germination and vigor of wheat seeds.

---

Fertility, developmental time and adult longevity of walnut aphid, Chromaphis juglandicola (Kalt.) and its parasitoid wasp, Trioxys pallidus (Hal.) were studied under controlled conditions with a constant temperature of 26±2^oC, relative humidity of 60±5%, and 16:8 (L:D) photoperiod. Populations of walnut aphid and parasitoid wasp were reared on walnut seedling in a growth chamber. The mean developmental period, daily fertility rate, and progeny sex ratio were combined to construct demographic life tables. From these tables, intrinsic natural rate of increase (r_m), net reproductive rate (R₀) and mean generation time (T_c) were calculated. The net reproductive rate (female offsprings per female per generation) and intrinsic rate of natural increase values were 34.69 and 0.278 in walnut aphid and 53.85 and 0.385 in parasitoid, respectively. The mean generation time was 12.75 days in walnut aphid and 10.35 days in parasitoid. Values of r_w (weekly multiplication of the females) indicates that T. pallidus is able to multiply 14.81 times per week, whereas the population of walnut aphid multiplies by only 7.001 times in the same period. The population of parasitoids doubled within 1.8 days while the aphid took 2.49 days. Mean pre-imaginal period was 9.14±0.34 days for male and 9.16±0.12 days for female parasitoids on a mixture of different nymphal stages of host. In walnut aphid it was 9.30±0.10 days. The pre-imaginal periods of parasitoid decreases as the aphid host ages. Longevity of adult male and female was 6.17±0.22 and 6.87±0.23 days, respectively, and 12.24±0.94 days for walnut aphid.

---

Downslope soil movement along riverbanks is a significant erosion process. Plant roots, particularly of woody vegetation, apparently stabilize soil on slopes because in most areas where the vegetation is removed, frequent bank failure occurs. Plant roots increase soil-shearing resistance both directly by mechanical reinforcement and indirectly through removal of pore water by transpiration. In this study, the effects of two plant species on the stability of the Karoon River has been investigated. To determine the In-situ shear strength of soil, a special device was designed and manufactured. This device is capable of measuring the shear strength of soil blocks as large as two cubic meters. In this study, twelve soil blocks, four blocks with roots of each tree and four blocks of root permitted were measured. Comparison of the soil shear strength with roots and root permitted soil shows that tree roots can significantly increase the shear strength of the soil. The amount of increase depends on the type of plant, the age of plant, the diameter of the roots and the percentage of roots in the block. In this study, the amount of increase varied between 20-66%. From the analysis of the data, two equations were developed to determine the increased shear strength.