JWSS - Journal of Water and Soil Science

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The first step in fundamental breeding of any living organism is the determination of its genetic make-up. To investigate the genetic make-up of the European honeybee (Apis mellifera L.) in Iran, some research attempts were made during the years 1992-1996 in which the bee's relationship with some exotic races were determined through the application of morphological methods. For this purpose 13000 samples of worker bees from 1320 colonies of 212 apiaries in 104 cities at 25 provinces were taken and twelve morphological characters were measured by using the international method (Ruttner, 1978). Furthermore, seven morphological characters of 900 drone samples taken from 403 colonies of 111 apiaries in 42 cities at 10 provinces were studied through the same method. The principle component analysis (PCA) was used for statistical analysis of the data obtained. The results indicated that the existing populations of honeybees under study were of the Iranian honeybee race (Apis mellifera meda) which were completely distinguishable from those of imported races such as A.m. carnica, A.m. ligustica, A.m. caucasica and exotic races such as A.m. anatoliaca, A.m. syriaca A.m. yemenitica and A.m. lamarkii. The imported races had not had great genetic impact on the Iranian race, as the Iranian honeybees have had good consistency and stability. In addition, import of the exotic queens has been ceased in the last decade.

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A 46-day feeding trial was conducted with rainbow trout (Oncorhynchus mykiss) to examine the effects of partial substitution of plant protein sources with fish meal in diets. Three different sources of plant protein including soybean, sunflower and cottonseed meals were substituted by fish meal at four levels of 10, 20, 30 and 40 percentages. Each diet was assigned to triplicate groups of fish in a completely randomized design as a 3×4 factorial arrangement, with a control diet. Seven hundred and eighty fish were used in this trial. Twenty fish were randomly assigned to each of 39 pens and were acclimated in these pens to the experimental conditions two weeks before treatments began. This substitution caused no significant differences in all the criteria measured with control diet. Fish fed diets of 30 and 40 percent soybean meal substitution showed greater weight gain and better growth performance, lower FCR and higher PER values in comparison with the fish receiving other diets, although the differences were not significant. Irrespective of substitution levels, comparison of fish fed by three different sources of plant protein in their diets showed that the fish fed diet containing sunflower meal had significantly (p<0.0l) lower final mean weight and growth performance, higher FCR and lower PER than the fish receiving soybean and cottonseed meal diets. Relative liver weight of fish receiving soybean meal diets was significantly (p<0.0l) higher than those fed with cottonseed meal diets, but the difference was not significant when compared with the fish fed with the sunflower meal diets. Partial replacement of cottonseed meal resulted in a higher energy availability to fish and also better performance of fish. However, diets containing soybean meal showed not much effects on performance of rainbow trout. These results indicate that cottonseed and soybean meals can be recommended as a suitable and fish meal-sparing ingredient in diets for rainbow trout.

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Irrigation systems may or may not be well designed and properly used. Therefore, it is necessary to study these systems to provide direction to management in deciding whether to continue existing practices or to improve upon them. The major objective of this study is to determine the evaluation factors of center-pivot irrigation system and factors which usually affect irrigation performance. A solution. for the improvement of irrigation water use will be presented and design and management problems, will also be mentioned. To achieve the objectives of this study, the characteristics of the soil and the growing plant (seed corn) along with design parameters were determined. The system was designed on the basis of soil and the growing plant characteristics in the 500-ha farm of Ministry of Agriculture (located in the North East of Meshkinabad, Karaj) having a silty loam texture. Then, it was examined with respect to the existing conditions. Four radial rows of catch containers spacing 6 meters were set up and then field data for performance evaluation of system were determined. The evaluation factors were calculated on the basis of field data analysis. The results obtained are as follows: During the growing season, the average PELQ, AELQ and DU for the center-pivot system were about 79, 75.8 and 84 percent, respectively. Analysis of evaluation factors indicated that the system is not efficient DU and PELQ values were not high enough for the system because it was not properly designed for the existing conditions. Al the same time, it seems that the difference between PELQ and AELQ values are meaningful which may indicate management difficulties.

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Seven Iranian and foreign cultivars of rice were crossed in a half-diallel. Parents with F2-generations were transplanted in a randomized complete blocks design with 3 replications and evaluated for length to breath ratio of paddy and brown rice, head rice and crust, grain yield, percent of head rice and broken rice, amylose content, gelatinization temperature and gel consistency. The ANOVA table showed significant differences among genotypes, general combining ability effects for all traits and specific combining ability effects for length to breath ratio of paddy and brown rice, percent of head rice and broken rice, so representing additive and non-additive effects in genetic control of the traits involved, respectively. The graphical analysis of the results showed partial dominance for length to breath ratio of paddy and brown rice, grain yield, amylose content, gelatinization temperature and gel consistency. Because of additive gene effects, genetic advance from selection would be high for these traits. The genetic control of brown rice weight is complete dominance, and for weight of head rice and rice crust weight over dominance involved. So, genetic advance by selection for these traits would be poor. In the genetic control of higher length to breath ratio of paddy and brown rice, brown and head rice weight, grain yield and amylose content recessive genes are involved. Domsiah for higher to breath ratio of paddy and brown rice and Sepidrud for brown and head rice weight had the most recessive genes. IR28 for higher grain yield and Sepidrud for less crust weight had the most recessive genes.

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In a completely randomized design, 600 commercial day old broiler chickens were used to study the possibility of replacing corn with barley. Each of 10 experimental diets in which corn was replaced with barley at levels of 0, 5, 10, 20 and 40 percent, with and without tallow, were given to 4 replicates of 15 chickens each. At 42, 49 and 56th days of age, one male and one female from each pen were killed. Body weight gain, feed intake and feed conversion ratio were not affected by different levels of barley at 42th day of age. Increasing the level of barley had not effect on body weight gain at 56th day of age. Feed conversion ratio improved slightly due to addition of 4% tallow to the diets containing different levels of barley. Abdominal fat was increased due to added tallow in males and females. Increasing slaughter age increased abdominal fat in both sexes. Difference in abdominal fat in females was more than males.

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Growth and grain yield of irrigated barley cultivars (Valfajr, Binam and Raihaneh) was investigated at 4 sowing dates (6, 22 Oct. and 14, 20 Nov.) in Karaj region. The effect of sowing date, genotype and their interaction on grain yield were statistically significant. Early and late sowing enhanced cold damage. However, the damage was more in late sowings. It was estimated that the optimum sowing date would be about 50 days (600 GDD) prior to freeze-up and maximum cold damage would occur when sowing was delayed until some 22 days (230 GDD) before freeze-up but any more delay in sowing would cause less damage. Highest grain yield was obtained from Raihaneh at 22 Oct. sowing. Binam showed good yield stability and relatively high yield, especially in unfavorable sowing dates. In the relatively favorable sowing dates (6 and 22 Oct.), grain weight showed positive correlation with linear grain filling rate, storage and translocation of reserves. LAI, LAR, RGR, CGR and LAD of each cultivar were higher in the second sowing date compared to the first one. The “ratio of post anthesis growth to maximum TDM” showed a high correlation with the harvest index. Raihaneh was the highest cultivar in resistance to lodging, harvest index, storage and retranslocation of assimilates, and linear grain filling rate. It is suggested that at favorable sowing dates, Valfajr and Binam had source limitation or disturbed translocation and Raihaneh had sink limitation.

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Optimum rice population densities and the response of rice yield and yield components to population densities and planting pattern are important factors helping rice producers and researchers to achieve maximum productivity. For this reason, a randomized complete block design experiment was conducted during the summer of 1995 at Isfahan University of Technology Research Farm located at Lavark, Najafabad. Zayandeh-rood cultivar was transplanted with three seedlings per hill at row spacing of 15, 25 and 35 cm and hill spacing of 10, 15 and 20 cm under flooded conditions. Row spacing influenced the plant height significantly at heading and anthesis stages. Wider row spacing, enhanced days to 50% heading and anthesis and consequently grain filling duration and ripening stage coincided with unfavorable conditions at the end of the season, which decreased the percentage of maturity. Although number of tillers per unit area increased, tillers per plant decreased as row spacing was reduced. Narrow row spacing limited vegetative growth after anthesis and thereby growth rate of panicle increased. With reduction of row spacing, without any change in the percentage of full grains per panicle and grain weight, number of panicle per unit area increased but number of grains per panicle decreased. At greater row spacing, grain yield per unit area decreased although grain yield per plant and harvest index increased. Although, effects of hill spacing were similar to those of row spacing, hill spacing usually did not influence plant characters, yield components and grain yield significantly. Stepwise regression and path-coefficient analysis revealed that number of panicle per unit area is the most important yield components. It also showed that indirect effects of panicle per unit area on yield through its association with grain per panicle prevented real effects of grain per panicle on yield. Fifteen × 15 cm spacing produced maximum yield which is probably recommendable for rice production in Isfahan.

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Effect of different times and levels of nitrogen fertilizer application on growth and grain yield of spring wheat cultivar “Ghods” was studied during 1993-1994 growing season at Karkadj, Agricultural Experiment Station, College of Agriculture, University of Tabriz, using a split plot design with three replications. Main plots were assigned to five levels of N fertilizers (0, 40, 80, 120 and 160 kg/ha) and subplots to five times of applications [all of N fertilizer at planting (T^₀) 1/2 at planting + 1/2 during tillering stage (T₁), 1/2 at planting + 1/2 during heading stage (T₂), 1/3 at planting + 1/3 during tillering and 1/3 at heading stages (T₃) and 1/4 at planting + 1/4 at tillering + 1/4 at stem elongation and 1/4 at heading (T₄)]. Results showed that different levels of N applications affected grain yield and biological yield significantly, while the effect of split application and also N levels × times of application interaction on these two traits were non-significant. Growth stages of wheat were not significantly affected by different N Levels and times of application. Dry matter accumulation, leaf area index, and crop growth rate, in response to growing degree days during growing season, increased when higher levels of N fertilizer were applied. Leaf area index and crop growth rate initially increased up to anthesis and then decreased. Crop growth rate decreased to zero level at soft dough stage and then became negative. Variations in relative growth rate and net assimilation rate, in relation to growing degree days, decreased when different levels of N fertilizer were applied at early part of growing season it was maximum while at later growth stages decreased and finally became negative, Times of N application and level × time interaction during growing season did not affect the growth indices significantly.

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As unit hydrograph is an important item in flood estimation of the rivers and since flood hydrograph and simultaneous rainfall hyetograph is needed to derive a unit hydrograph, hydrologists recommend synthetic unit hydrographs for areas lacking these hydrometeorological data. A research was conducted in the Zayandehrud-dam watershed (Pelasjan sub-basin) to test the efficiency of synthetic unit hydrographs (Snyder, SCS, and Triangular methods) in hydrological evaluations. For the purposes of this study, natural and synthetic unit hydrographs were determined and compared, using all morphologic, hydrometric and rainfall data. The results showed that Triangular and SCS methods fit natural unit hydrographs better than Snyder method does, but peak instantaneous flow is estimated to be higher than the observed flow. So, the constant 2.083 in peak flow equation is recommended to be changed to 1.74 in this watershed. The Snyder method predicts good peak flows, compared with the other two methods. Generally, it is concluded that Triangular, SCS, and Snyder methods are ranked 1 to 3 for determination of synthetic unit hydrographs in this watershed.

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A total of adult leghorn roosters and 360 day-old broiler chicks were used in two completely randomized experiment to evaluate metabolizable energy (ME) and feeding value of faba beans in broiler rations. In a factorial arrangement with 10 treatments and 3 replicates chicks were fed isonitrogenous rations containing either 0, 10, 20 or 30 percent of raw, cooked or dehulled faba beans for 8 weeks. Data from sibbald procedure showed cooking had no significant effect on energy value of beans, while dehulled beans had a significantly (p < 0.05) higher energy value. Final body weights at 8th week of age were unaffected due to processing of beans. No significant differences were observed in liver weight, abdominal fat or feed efficiency ratio due to processing and/or percentage of beans in the ration. Raw, whole beans significantly (p < 0.05) increased percentage and weight of pancreas compared to those that had consumed dehulled beans. This indicates that trypsin inhibitor is located in hulls. Cooked beans reduced pancreas size to normal, indicating destruction of inhibitor due to cooking. One interesting point is that the control group which consumed more soybean meal had a pancreas weight of 4.67 grams comparable to 4.83 grams of pancreas weights of chicks consuming raw, whole beans. This last fact indicates that soybean meals might not have received enough heat treatments during processing, which requires further investigation.

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Physiographic characteristics of Atrak Watershed described by a number of parameters were used in regression models to estimate maximum daily discharges. These parameters were sub-watershed area, main waterway length, mean waterway slope, mean watershed elevation and mean watershed slope. Based on the results of correlation between the above parameters and their suitability for discharge estimation, three regression models were developed for further analysis. Model 1 applied area as the independent variable to estimate maximum daily discharge. In model 2 area and mean watershed elevation were the independent variables. Model 3 used area and mean waterway slope as the independent variables. Even though the results of testing did identified all three models as appropriate for application, further testing selected model 1 as the most appropriate. Recommendations were made for model application to similar watersheds lacking the necessary data.

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To determine the effects of field slope, emitter discharge, irrigation water volume and soil texture on soil moisture profile and soil surface wetted shape from a point source, field data were collected on three different soil types, three emitter discharges (4, 8, and 12 lph), four slopes (0, 2, 5, and 10%), and five irrigation water volumes (10, 20, 30, 40, and 50 liters) with three replications. The results showed that the surface-wetted area increases as the emitter discharge increases. The surface-wetted area decreased with a corresponding increase in emitter discharge in experimental fields with light-textured soils. In experimental fields with heavy textured soils and slopes greater than 5%, the changes in surface-wetted area due to the emitter discharge increases, were higher compared to slopes of less than 5%. Since, a higher emitter discharge would result in higher surface-wetted area, the results showed that for an equal volume of irrigation water, the soil moisture profile was deeper for lower emitter discharge. In general, the volume of wetted zone was higher for greater emitter discharges. It was found that as the volume of irrigation water increased, the volume of wetted zone would increase correspondingly. This effect is more prominent than that of emitter discharge. In general, the depth of wetting front was lower and the wetted surface area was greater for heavy textured soils as compared to the light textured soils. The wetted-surface area and the shape of wetting front in the direction of slope were affected by the soil infiltration, emitter discharge and volume of irrigation water where these effects were more critical in higher sloping lands.

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In order to study the effects of rate and time of nitrogen application on vegetative characters, i.e., yield and yield components of rice (Zayandeh-rood variety), an experiment was conducted at Isfahan University of Technology research farm during summer 1996. Four N rates including (60, 90, 120 and 150 KgN/ha) and four splitting form (1- all N applied before transplanting 2- 1/3 N applied before transplanting, 1/3 at the beginning of tillering and 1/3 at the emergence of first panicle in 50% hills 3- 1/2 at the beginning of tillering and 1/2 at the emergence of first panicle in 50% hills 4- 1/3 at the beginning of tillering and 2/3 at the emergence of first panicle in 50% hills) were evaluated in a factorial experiment which was arranged in a randomized complete block design with 3 replications. Plant height, number of tillers per unit area and days to heading and maturity increased with an increase in the rate of fertilizer application. Grain yield and number of panicles per square meter increased when the N rate was raised to 120 Kg N/ha, while application of 150 Kg N/ha resulted in the reduction of grain yield and number of panicles. Nitrogen rate increases did not have any significant effect on number of grains per panicle. The grain weight did not follow any particular trend at different application rates, but harvest index and percentage of filled grains were decreased as the N rate increased. The percentage of nitrogen content of plant was increased as a result of higher N - rate at heading and harvest times. Treatments containing base application of nitrogen resulted in an increase in plant height, number of tillers, plant dry matter, grain yield and number of panicles per square meter, although it caused a reduction in harvest index. The number of grains per panicle and grain weight did not follow any particular trend under the influence of time of application, although plant nitrogen content increased with a delay in time of fertilizer application.

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Methods of seedbed preparation affect establishment, growth and yield of crops via manipulating physical and chemical properties of soil. These effects on wheat-mungbean double-cropping have not been studied in Isfahan. Therefore, the influences of various seedbed preparation methods on soil physical properties and nutrients content and on establishment 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 unburned) along with four tillage systems (moldboard plow, disk, khishchee and no-till) were laid out in a strip plot design within a randomized complete block design with four replications. Bulk density and penetrability of soil at various depths were not affected by residue management at emergence. However, at the time of flowering, bulk density at 0-15 cm soil depth was lower and soil penetrability at 3-15 cm depth was higher in unburned treatment due to mineralization. Rate and coefficient of emergence of seeds were lower in unburned residue treatment. Soil bulk density at 0-30 cm depths was lower and penetrability at 3-21 cm depth was higher with moldboard plowing at both emergence and flowering time. In addition, lower soil N, P and K content at 0-15 cm depth at emergence and flowering time was obtained with moldboard plowing. Rate and coefficient of emergence were strongly lower in no-till treatment. Based on these results and considering sustainable agricultural goals, incorporating residue with disk tillage might be advantageous under conditions similar to this experiment.

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Knowledge of the vegetative and reproductive characteristics of soybean cultivars with different growth habits and maturity groups is essential for the selection of a suitable variety as well as for providing optimum conditions for their growth. In 1994 in a field located in Kholenjan of Isfahan, Iran, nine indeterminate type cultivars belonging to different maturity groups, namely Williams, Wood Worth, Hack, Zane, Black Hawk, Bonus, Steel, S.R.F. and Harcor and one determinate cultivar belonging to maturity group III namely Hobbit, in a complete block design with four replications were evaluated. Indeterminate cultivars and higher maturity group cultivars produced more dry matter. On the whole, indeterminate cultivars with later maturity had longer main stem with more nodes, pods and grains. The determinate cultivar had more lateral branches, and more pods and grains in them but these traits did not show any specific trend in different maturity groups. Height of the first pod from ground surface in indeterminate cultivars was more than that of determinate cultivars. Number of pods per each node of main stem, number of grains per each pod of lateral branch and number of nodes per lateral branch showed no significant difference among cultivars. Classification of these cultivars based on the above characteristics showed that cultivars with different growth habits had basic differences and also that some cultivars showed some similarity to maturity groups which did not exist in the present study.

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Immature embryo culture response of 28 durum wheat (Triticum turgidum var. durum) cultivars was studied using MS medium in Tissue Culture Laboratory of College of Agriculture, Isfahan University of Technology. Donor plants were grown in a recirculating hydroponic system and pots in a greenhouse. Regenerated immature embryos were recorded at 2, 4, 8 and 16 days after inoculation. Assessment of durum wheat cultivars for immature embryo culture was conducted by percentage and rate of regenerated embryo, using a split plot design arranged in completely randomized design with 5 replications. The analysis of variances showed that there were highly significant differences among cultivars for plant regeneration capacity. The highest potential and rate of embryo regeneration (two days after inoculation) were observed in “Shahivandi” which is a native cultivar of west Iran. “Awl1/Sbl4” with a mean of 48.5%, “Hagla” and “Ofen/Kil” with a mean of 80% have the poorest and the best mean of regeneration during the recording period, respectively. The high regeneration potential is important in view of reducing the time constrain and somaclonal variation in a breeding program.

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Feeding high levels of barley to laying hens is accompanied with dirty eggs, decreasing the feed intake and egg size. To improve the diet with barley for layers, different chemicals including a commercial enzyme effective on barley (Fin Feed), cupric sulfate pentahydrate, sodium bicarbonate, magnesium sulfate and oxytetracycline antibiotic were supplemented to experimental barley based diets. It was found that the commercial enzyme had a significant effect on layer performance. Other treatments didn't have any considerable effects on their performances. Enzyme supplementation significantly (P < 0.05) improved feed intake, production rate and daily egg mass production of laying hens. No significant difference were observed in laying performance of mature birds fed with barley-based diet or soybean corn diet.

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This experiment was carried out to study the effects of different levels of vitamin C (0, 150, 300 and 450 ppm) and cage density (3, 4 and 5 birds) on performance and egg shell quality of laying hens under high environmental temperature. In a completely randomized design with 3 × 4 factorial arrangement, one hundred and ninety two (192) 25 week white leghorn hens were divided into 48 replicates four hens per replicate. The experimental period lasted 90 days. The criteria measured were: percentage production, egg weight, egg output, feed conversion ratio, shell thickness, shell weight, shell calcium and albumin height. Daily egg production and biweekly egg weight, shell thickness, shell weight and albumin height were recorded. Shell c1acium was measured at the end of the experiment's period. The results indicate that, 150 ppm vitamin C significantly (P < 0.05) increased egg weight and shell calcium. Albumin height was significantly (P < 0.05) increased at 300 ppm vitamin C supplementation. Cage density had no effects on shell weight, thickness and calcium, and albumin height. Egg weight, egg production and egg output were reduced significantly (P < 0.05) due to increased cage density. Feed conversion ratio was also increased significantly (P < 0.05) as cage density was increased. Interactions between vitamin C and cage density on shell and egg weight were significant (P < 0.05).

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The production and acreage of corn in Iran and in Fars Province, in particular, are expanding at an increasing rate. The impacts of this event was studied by a risk programming model (MOTAD). The results indicated that the optimal cropping patterns with corn had less variance than the optimal patterns without corn in all income levels. The results also showed that with the introduction of corn into cropping pattern, the use of land and water were increased, but the rate of increase in the use of land was more than the rate of increase in the use of water. By determining risk - aversion coefficient for the sample farmers, their sensitivity to corn price changes were studied. The results indicated that the relationship between corn and wheat is complementary but it is competing with barley, sugarbeet, cotton, cucurbits and legumes.

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This study aims to evaluate the present management of border irrigation systems applied to wheat, alfalfa and sugar-beet farms in Boyer-Ahmad and Gachsaran cities in Kohgiloyeh and Boyer-Ahmad Province. Experimental farms included 8 alfalfa farms, 5 wheat farms and 5 sugar-beet farms. The experiments were conducted at different growth stages of plants and customary borders with prevalent dimensions, slopes, and management practices. The relationship between management allowable deficit, moisture deficit before irrigation, and infiltrated depth indicated that in most cases either “deficit irrigation” or “stress irrigation” had been applied. This type of irrigation has positive effects on water use but negative effects on supply of required soil moisture for plants. In the first to third irrigations, measured application efficiencies ranged from 40.8% to 100%, 52.2% to 100%, and 61.1% to 100%, respectively. Graphs of advance, recession, and ideal recession showed the effects of border slope and length on inflow cut time and uniformity of water distribution. Water infiltration curves showed the amount of deficit irrigation. The results showed that weak irrigation management is the result of three parameters: lack of knowledge on the part of farmers about soil moisture conditions and correct time for irrigation, weak irrigation scheduling, as well as an imbalance between available water supply and irrigation requirements which leads to wasting water and reduced irrigation efficiency.