JWSS - Journal of Water and Soil Science

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Mutual understanding among officials and followers has been a point of concern in behavioral management. Natural resources extension which, from the very first step, is concerned with the exploration of practical problems is in serious need of an atmosphere of mutual understanding between agents and clientele. In this research, attention was drawn toward the measurement of mutual understanding between executives and nomads regarding nomads’ problems in utilizing natural resources and breeding cattle in Isfahan Province. For this purpose, initially, understanding between nomads and natural resources administrators (extension agents and specialists) regarding their respective problems were measured and compared. The research population of the study consisted of two groups. The first, involved 32 administrators, extension agents and specialists, and the second, 75 nomad families. Two different questionnaires were developed for the study as research instruments in which 52 items regarding nomad problems were included. Each part of the population was asked to rank the items accordingly. Then, some nonparametric tests such as Kruscall Wallis and Mann Whitny U tests were applied to compare the mean rank for each item within and between the two groups.

Results showed that the administrators and nomads had different attitudes in only two of the 52 items. Administrators had no statistically significant different attitude in 52 problems. Eliminating the discriminating items, the attitudes in only two groups were compared and results showed that they had no significant difference in the remaining 48 items. Therefore, extension agents can follow these problems based on their mean rank priority in their developmental projects. This method of data reduction and understanding field constraints can be applied to the studies dealing with planning agricultural and/or natural resources development projects through extension education.

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The esterification process causes some desirable changes in physicochemical properties of fat by exchanging the acyl groups in triglyceride molecules. The aim of this study was to produce a suitable edible fat for industrial and home uses. In this study a mixture of 60 percent soybean oil and 40 percent edible tallow were inter-esterified, using 0.5 percent sodium methylate or ethylate as catalyst. The results obtained for solid fat contents and melting points indicated that the process of inter-esterification was accomplished in 30 minutes at 90°C. It was also observed that sodium methylate and. ethylate had similar effects on physical and chemical characteristics of the esterified blend. Iodine and saponification values indicated that the esterification process did not have any considerable effect on the degree of unsaturation or molecular weight of fatty acids. The peroxide values showed that the processing condition did not produce any peroxide. The esterified blend contained 1.10 percent trans fatty acids, which were originally present in the tallow. It is concluded that interesterification of soybean oil and edible beef tallow can be used as an alternative method to hydrogenation to produce a suitable plastic fat with low levels of trans fatty acids for the manufacture of different types of margarines and fats for home uses.

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Macaroni is a food product generally considered as one of the paste products. These products are produced from semolina that is, in turn, produced through special processing of milled durum wheat. In order to examine the effect of α-amylase on macaroni quality, three cultivars, namely Yavarous, Zardak and Altar 84, were chosen from each of which some wheat sprouts were prepared and mixed with unsprouted samples to obtain three ranges of falling numbers of 500-1000, 300-350 and 150-200 seconds.

The results from this study specified that the active presence of α-amylase in the samples reduced cooking time and colouring of the macaroni, while small amounts of the enzyme improved the breakage and modulus of elasticity of the samples. The α-amylase enzyme showed no effect on the colour of semolina and the macaroni stickiness. 

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Recent restrictions on the use of artificial food colours have prompted extensive research on natural pigments as suitable substitutes. The red beet Beta vulgaris L. has been found as a suitable source of natural red pigment since beet powder and concentrates can conveniently be used in food products. In this research, hot and cold extractions of randomly selected red beets were used after preparation and blanching. The extracts were filtered and passed through a column of Amberlite XAD-7 resins after adjusting the pH to 2.5. The adsorbed colour compounds were extracted from the resins by eluting the column with acidified alcohol. The solvent was removed by vacuum rotary evaporator and solid colour was obtained, using a freeze dryer.

Physicochemical properties of the solid colour were determined by measuring ash and sugar contents of the solid colour. Also, its purity and stability were investigated under different conditions.

The amount of ash and sugar were negligible. The highest stability was observed at a pH value of 5 under cold and dark storage conditions. The purity of the solid colour was determined by scanning in the range of visible wavelengths and preparative TLC. The result showed that purity of the colour as a hundred percent betacyanins. The yield of production was calculated as 2.7 g powder per kilogram of beet. The colour was used in producing ice cream and frozen sherbets, which showed to be a suitable replacement for artificial colour carmoisine. Also the production cost of the colour was as low as less than 0.1 percent of that of ice cream or frozen sherbets.

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Four cultivars of olive, Kalamata, Marri, Zard and Fishmi were obtained from Roodbar town and treated with two methods, natural and controlled fermentation with Lactobacillus plantarum as a starter culture at 25°C for 100 days. HPLC analysis experiments were conducted during the whole study period. A higher level (1.08% w/w) of total acidity was produced in Fishmi cultivar especially in the natural fermentation (0.8-1.1 g lactic acid/ml) than in other cultivars. Individual organic acids were determined by HPLC. Quantitative changes of organic acids in olives showed (P<0.0l) an increasing pattern of lactic and acetic acids during fermentation, but decreasing levels of malic and citric acids were revealed. The highest level of lactic acid (1.1% w/v) was observed in Zard cultivar and the type of fermentation had no effect on acid production. Malic and citric acids gradually disappeared during 50 days of fermentation period and this change was faster for citric acid during controlled fermentation. Malic acid did not follow this pattern.

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Evaluation of nutrient status in soil is important from nutritional, environmental and economical aspects. Potassium is a very important plant nutrient not only because of its large demand, but also because of its important physiological and biochemical functions in plant. In order to evaluate K availability and common K extractants in the central region of Isfahan Province, surface soil samples from 26 important soil series were taken, out of which 16 soil samples were selected for further study based on their ammonium acetate extractable K and texture. Available K was extracted from the soil samples by NH₄OAC (4 methods), CaCl₂ (2 methods), NaCl (2 methods), NaOAC, AB-DTPA, Mehlich I, Mehlich III, Morgan-Wolf and HNO₃. A green house experiment using corn (Zea mays L.) variety Single-cross 704 as the test plant with 2 treatments (zero and 150 mg/kg K) and three replications was performed with the 16 selected soils to correlate K uptake with K extracted by different extractants.

 From XRD analysis, the dominant clay mineral was found to be Illite. Based on the amount of potassium extracted by these extractants from the soils the extractants used in this research may be divided into three groups: relatively weak extractants including CaCl₂, Mehlich I and Morgan-Wolf relatively strong extractants including NH₄OAC, NaCl (2N), Mehlich III, AB-DTPA, NaOAC and NaCl (1N), the strongest and weakest extractants in this group were NH₄OAC and NaCl (1N), respectively and finally, a very strong extractant which includes only HNO₃. In each group, the quantities of extracted K showed high correlation with each other. A high and significant correlation was observed between the quantities of K extracted by NH₄OAC, AB-DTPA and HNO₃. The amount of K extracted by 2N NaCl, 1N NaOAC, 1N NH₄OAC, and AB-DTPA was significantly correlated with K taken up by plant and its K concentration. 2N NaCl and 1N NaOAC were selected as the most suitable extractants for K based on their high correlation coefficients with plant uptake (0.79** and 0.72**, respectively) and K concentration in plant (0.86** and 0.85**, respectively). Yield, relative yield and plant response were not significantly correlated with K extracted by different extractants indicating that available K of the selected soils was not a limiting factor for corn growth therefore, it was impossible to determine the critical level of K for corn by the selected extractant.

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An experiment was conducted in order to study the possibility of compensatory growth by changing dietary nutrients concentration in the female Arian broiler chicks using a completely randomized design by means of standard and diluted diets. By standard diet is meant diet recommended by Arian’s guide catalogue and by diluted diet is meant the diet used in Iran broiler farms. However, both diets contain the same nutrient/energy ratios. Chicks in the seven treatments received in their starter, grower and finisher stages standard and standard and standard, standard and diluted and diluted, diluted and standard and diluted, diluted and diluted and standard, diluted and standard and standard, diluted and diluted and diluted, standard and standard and diluted respectively. Furthermore each treatment contained three replicants and each replicant contained 30 chicks. This experiment was conducted in autumn using 630 female Arian broiler chicks for eight weeks.

 It was concluded that weight gain of chicks receiving standard diets during all stages of their growing period was the same as the chicks receiving diluted diet during their starter period and standard diets during grower and finisher periods. Feed consumption and feed conversion ratio of these treatments were statistically lower than other treatment groups. Furthermore, production index and percentage of mortality was better than other treatment groups. Likewise, viscera% and abdominal fat% remained significantly constant in all treatment groups. But the cost of feed per unit of live body weight was lower in the treatment receiving diluted diets in all three stages of their growing period.

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The antifungal effect of sodium diacetate on inhibiting the growth of some bread spoiling molds was examined both in culture media and in flat bread “In situ”. In the first step, the antifungal effect of different concentrations of sodium diacetate: 0, 1000, 2000, 3000, 4000, and 5000 ppm were examined against Aspergillus sp., Aspergillus niger, Rhizopus sp., and Penicillium sp.

The results indicated that as the concentration of sodium diacetate increased, the mold growth decreased. At 5000 ppm the mold growth was inhibited up to fifth day (the last day of experiment). Based on these results, the antifungal effect of different concentrations of sodium diacetate was evaluated in bread “In situ”. In this stage Aspergillus sp. was selected as the indicator mold. The results indicated that if 3000 ppm of sodium diacetate is used, not only mold growth is inhibited but bread staling can also be prevented. This concentration of sodium diacetate does not have any harmful effect on texture and flavour, and can increase bread shelf life up to four days. Higher concentrations of sodium diacetate can inhibit mold growth completely, but have negative effects on texture and flavour. Therefore, 3000 ppm of sodium diacetate is recommended for increasing bread shelf life.

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Flood is one of the catastrophic events that has attracted the hydrologists’ attention. In this research one of the important flood indices, i.e. maximum-daily mean-discharge, was determined for several western Iran watersheds, namely, in the catchments of Gamasiab, Qarasou, Saimare, Kashkan, Sezar and Abshineh. Daily data were prepared from stream-gauging stations and a 30-year concurrent period was selected.

 Flood frequency analysis was performed using HYFA and TR computer programs and optimum distributions were chosen by goodness of fit tests. Extreme flow values having different return periods of 2, 5, 10, 25, 50, 100, 500 and 1000 years were calculated. Modeling was done with regional analysis using multiple regression technique between maximum-daily mean-discharge and physiographic characteristics of the basins. The most important parameter for the selection of the model was the adjusted coefficient of determination while significant level, standard error and observed discharger vs. computed discharge plot acted as controlling parameters. Finally, different models with different parameters were selected from power, exponential, linear and logarithmic forms. The results showed the power model to be the best among the four types. The main channel length, drainage density and time of concentration were the most effective parameters on flow. After analyzing the errors, it appeared that increasing the return period would cause an increase in the model error. At 1000-year return period, the error reached 32.2%.

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In order to analyze the genetics of tobacco cultivars’ resistance to blue mould (Peronospora tabacina A.) and to estimate the combining ability of the four resistant and susceptible tobacco cultivars (Bel 61-10, Bergerac C, Samsoun and Trumpf) received from CORESTA, these cultivars were crossed in 1997 in a half-diallel crossing system and in 1998 their parents and their progenies were sowed. Also to estimate gene effects controlling resistance and susceptibility of cultivars and to obtain F₂, BC₁ and BC₂ generations, F₁ generation was selfed and backcrossed with their parents. In 1999, the six generations (P₁, P₂, F₁, F₂, BC₁ and BC₂) from six families were evaluated in a complete block design with 3 replications and the resistance of genotypes against Peronospora tabacina were evaluated by the standard method of CORESTA and the parents with their F₁ and F₂ progenies were analyzed as a 4×4 half-diallel crossing system.

The ANOVA showed significant differences among genotypes concerning resistance to Peronospora tabacina and the generation means analysis indicated fit of families Bel 61-10 x Bergerac C and Bel 61-10 x Trumpf with additive-dominance model. The rest of the families showed non-allelic digenic interactions (epistasis) and were fit to 6-parameter model of Mather and Jinks. Because of moderate to high narrow sense heritability of resistance to Peronospora tabacina (from 34 to 85% for different families), the selection of resistant lines may be successful. The results showed significant GCA of parents for the resistance to Peronospora tabacina. So, the role of additive effects of genes concerning resistance to Peronospora tabacina was recognized and the estimated heritability (in the narrow sense) was from 72% to 75% for this trait.

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Two experiments were conducted to investigate the effect of dietary energy levels on the performance of Arian broiler chicks. Trial 1 was performed in summer and trial 2 in fall. Both experiments were accomplished in 5×2 factorial designs, involving 5 levels of dietary metabolizable energy and two sexes. Each of the 10 resulting treatments was replicated 4 and 3 times in trials 1 and 2, respectively. The metabolizable energy contents in diets number 1 to 5 were 2800, 2900, 3000, 3100 and 3200 Kcal/kg for starter (0-4 weeks) period and 2900, 3000, 3100, 3200 and 3300 Kcal/kg for grower (4-7 weeks) period, respectively. The ratios of energy to each nutrient were the same for all diets in each stage of the experiments.

In both experiments, body weight gain and feed conversion ratio improved significantly (P<0.01) when diets with higher levels of energy were consumed. Feed intake was affected (P<0.01) by the dietary energy content only in summer (trial 1) resulting from the reduced intake of chicks fed with the lowest energy level. Abdominal fat percentage was decreased (P<0.01) in chicks fed with the lowest energy diet in summer. In both experiments, the cost of the feed per unit of live body weight was reduced (P<0.01) in accordance with the reduction in diet density. As expected, body weight gain, feed conversion ratio, abdominal fat and cost of the feed per unit of live body weight for male chicks were significantly better than the same values for females (P<0.01).

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This 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 (2000, 2200 and 2400 IU/kg diet) on eggshell quality 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 W36 and 26 weeks old, were divided into 60 replicates, four hens per replicate. The experimental period lasted 90 days until the hens were 38 weeks of age.

The results indicated that shell strength, shell thickness and shell percentage increased significantly (P<0.05) at 3.06% Ca level. Calcium levels had no effect on ash shell percentage. Vitamin D3 did not have a significant (P<0.05) effect on ash shell percentage and calcium shell, but shell strength, shell thickness and shell percentage significantly (P<0.05) increased at 2400 IU/kg diet vitamin D3. Only plasma calcium raised significantly (P<0.05) due to the added vitamin D3. Interaction between vitamin D3 and calcium on shell strength, shell thickness, shell percentage and plasma calcium were significant (P<0.05). Correlation between egg shell quality parameters and blood parameters with calcium and vitamin D3 was significant (P<0.05).

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In this study 130 honeybee colonies in 4 locations (Damavand, Tehran, Qum and Karaj-Savojbolagh) were sampled to determine the phenotypic correlations among 9 morphological and 3 production traits. The morphological traits were length (FL) and width (FB) of fore wing, cubital index (CI), length of hind leg (HL), length of probosics (LP), slender index (SI), length (WL) and width (WT) of wax mirror, distance between wax mirror (WD), index of wax mirror (IW) and corbicular area (CA). The production traits were honey yield (WH), pollen gathering (WP) and wax: production (WW). Data were subjected to analysis of variance, phenotypic correlations, stepwise regression and path coefficient analysis. Results of phenotypic correlations demonstrated that correlations between FL with FB (0.65), WL (0.361), WT (0.261), HL (0.555) and LP (0.257), WH with WP (0.300), WW with WH (0.560) and CA with WH (0.234) were significant (P≤0.01). FB with WH (r=0.204) was also significant but there was no significant correlation between CA and WP. Results of stepwise regression and path coefficient analysis showed that whereas morphological traits were settled as independent variables, much of the corresponding changes in production traits remain uninterpreted. In spite of the significant correlations among several morphological and production traits, body measurements alone are not suitable criteria to select colonies for high productions of honey, pollen and wax.

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Nitrogen fertilizer application for corn (Zea mays L.) based on available N of soil can decrease the need to N fertilizer and, consequently, reduce the risk of environmental pollution, especially that of groundwater and drinking water. The objectives of this study were i) determining soil N0₃-N critical level at 4 to 6 leaf stage, ii) to study soil nitrate distribution, iii) determining N rate required for maximum corn grain yield, iv) measuring soil residual nitrate nitrogen after harvesting, and v) using hand chlorophyll meter to evaluate N status of corn. The experiment was conducted under field conditions in Bajgah and Kooshkak research stations (Fars Province) in 1996 using a split plot randomized complete block design with four replications. Main plots were control, 60, 120, and 180 kg N ha^-1 as urea. At 4 to 6 leaf stage each main plot was divided into two sub-plots and N was applied at 60 kg N ha^-1 rate to one sub-plot and the other sub-plot was left as control.

 Results showed that critical soil N0₃-N level at 4 to 6 leaf stage in 0-30 cm depth for 90 percent relative yield in Bajgah was 12-14 and for Kooshkak was 8-10 mg kg^-1 soil. The highest coefficient of determination between corn grain yield and soil N0₃-N in 0-30 cm depth for Bajgah was in furrow sample and for Kooshkak was in furrow and shoulder composite sample. In both sites, maximum corn grain yield, with 15.5% moisture content, was about 14 mg ha^-1 that was obtained through the application of 120 kg N ha^-1 as preplant plus 60 kg N ha^-1 as sidedress which is about 1/2 of the application rate used by local farmers. The highest residual soil N0₃-N after harvesting was 24 and 18 and the lowest was 2.6 and 3 mg kg^-1 soil for Bajgah and Kooshkak soils, respectively. When maximum corn grain yield was obtained, chlorophyll meter reading at the middle of leaf blade at dough stage, was 49 for both sites. It seems that N fertilizer application rate by local farmers is excessive.

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The urease enzyme plays an important role in the efficient use of urea fertilizer and some environmental risk assessment. Urease activities in 20 different soil samples of arid to semi-arid regions of Isfahan Province were determined and their correlations with some soil physical, chemical and biological characteristics were studied. Urease activities range from 5.3 to 79.2 µg NH4⁺ g^-1 soil 2hr^-1.

Results indicated that soil organic carbon was significantly correlated with urease activity (r=0.899***). None of sand, silt and clay percentages were significantly correlated with urease activity. Total nitrogen was significantly correlated with urease activity (r=0.797***). Electrical conductivity of saturated paste extracts were also negatively correlated (r=-0.499*) but sodium adsorption ratio (SAR), pH, equivalent calcium carbonate and cation exchange capacity failed to be correlated significantly with urease activity. No significant correlations were found between urease activity and total bacteria (on nutrient agar) or total fungi (on potato dextrose agar), but the bacteria that could colonize urea-agar media were significantly correlated with urease activity (r=0.47*). Multiple stepwise regression analysis showed that organic carbon accounted for most of the variation in urease activity.

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An experiment was carried out on 384 7d old commercial broiler chicks (Lohman) to study the effect of changes in source and level of dietary calcium and limestone particle size on the performance and tibial growth and calcification of broiler chicks. From day 1 to day 7, the chicks were fed with the commercial basal diet. On day 7, the chicks were weighted and randomly assigned to 64 groups, six chicks of similar body weight (82.2±5.4) per group. Each of the eight experimental diets was fed to eight groups of chicks for an experimental period of 49 days. Two calcium sources (oyster shell and limestone), two calcium levels (100% NRC and 85% NRC) and three particle sizes of limestone [ground (less than 0.15 mm), medium (0.6 to 1.18 mm) and coarse (1.18 to 4.75 mm)] were added to diets with the same energy based on a Randomized Complete Design, in which levels of calcium were nested into calcium sources. Particle sizes were nested into calcium sources and levels.

Limestone significantly increased phosphorus retention (in percentage of phosphorus ingestion) at the age of 21 and 56 days and increased tibial length, dry weight and ash weight at 56 days. Calcium level of 85% NRC significantly decreased feed intake and feed conversion, especially during the starter, and increased calcium retention (in percentage of calcium ingestion) at 21 and 42 days. Phosphorus retention and cortical thickness of tibia at 21 and 42 days, tibial dry weight, ash weight and ash percentage at 42 day, were significantly increased with calcium level of 100% NRC. Coarse and medium particle sizes of limestone as compared to ground particle size, significantly improved feed intake and feed conversion, especially during the starter. Medium particle size of limestone with calcium level of 85% NRC and coarse particle size of limestone with calcium level of 100% NRC, significantly improved tibia ossification characteristics and increased calcium and phosphorus retention. By using calcium level of 85% NRC, coarse and medium particle sizes of limestone compared to ground particle size, significantly diminished percentage of leg abnormalities.

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Effects of the β-adrenergic agonist metaproterenol were studied daily gain, carcass composition and feed consumption of Varamini female lambs were studied. Thirty lambs were randomly assigned to a randomized complete block design with three groups (treatments) and two blocks (live weight). The ration was similar for all groups (ME: 2.6 MCal/kg, CP: 14.9%) and lambs were fed ad libitum. Metaproterenol was injected subcutaneously at 0 (control), 7 (low dose) and 14 (high dose) µg kg^-1 w⁷⁵. Lambs were weighed at 20-day intervals.

Mean daily weight gain and feed conversion ratio improved significantly by metaproterenol (P<0.05), but feed intake was not affected. Hot carcass weight, carcass weight minus fat-tail, dressing percentage and longissimus muscle characteristics were different among the three groups (P<0.01). Physically separated fat from several depots and fat-tail weight significantly reduced in the metaproterenol groups. Carcass fat content decreased but carcass protein content increased in metaproterenol treated lambs.

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The quality of Iranian breads has intensively decreased during recent years due to socio-economic factors and poor quality of flour. The purpose of this study is to investigate the effects of mono- and diglycerides and ascorbic acid as improvers on Iranian bread (Taftoon) quality. Three wheat type flours (Ghods, Mahdavi and Roshan wheat varieties produced in Isfahan region) were used. The effects of ascorbic acid at three levels (20, 40 and 60 ppm flour basis) and esters of mono- and diglycerides at three levels (0.5, 1.0 and 1.5 percent) on the dough baking and bread quality were measured. The Taftoon bread was baked in a semi-traditional oven.

 Loaves of bread were scored after baking and also on the first and second days of storage at room temperature. Analysis of variances indicated that ascorbic acid and mono- and diglycerides have significant effects on the improvement of the rheological properties of dough. However, ascorbic acid had higher effects than mono- and diglycerides. The results of the tests showed that dough resistance to mixing and tensile stress increased with addition of the improvers. Both improvers used in this experiment have an anti-stabling effect on bread. However, the ascorbic acid effect is much less than that of mono- and diglyceride. The low concentration of 0.5 percent of mono- and diglyceride and 60 ppm of ascorbic acid with flours of moderate protein contents (10-11%) resulted in good quality Taftoon bread with good organoleptic and tearing qualities after two days.

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A field survey was carried out in Firoozabad Beneh (Pistacia mutica) Forest Station covering about 12000 hectares. Data were collected using combined random and systematic sampling methods to study the effect of altitude, dominant slope direction, sex and age of the host and plant canopy on rust severity caused by Pileolaria terebinthi.

The rust severity decreased with plant age and elevations above 2000 meters. Female trees were more susceptible to the pathogen than males. The slope direction and plant canopy had no effect on disease severity. There was a significant correlation between plant age and elevation with disease severity but not with plant canopy. Regression analyses indicated a linear regression between disease severity variables and dependent variables of age, sex, and elevation.

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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.