JWSS - Journal of Water and Soil Science

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Diallel crosses among 6 Avena sativa L. and A. sterilis L. lines and introductions were used to evaluate the validity of the assumptions for the genetic model. Number of days to pollination, plant height at pollination and at maturity, as well as grain and stem protein percentages were evaluated. According to Griffing's method 1 the reciprocal mean squares for all the traits under study were significant. But based on Hayman's analysis, the maternal effects for all the traits studied were not significant. Therefore, reciprocal means were used to evaluate the validity of the absence of multiple alleles, linkage and epistasis effects using regression of W_r on V_r and analysis of variance for W_r + V_r and W_r - V_r. Based on the results of the 3 methods, the genetic models for plant height at maturity and days to pollination were unbiased. Therefore, Hayman's analysis was used to estimate the genetic parameters for these traits. For plant height at pollination and stem protein percentage, significant and nonsignificant differences of regression slope from one and zero (Ho: β = 1 and Ho: β = 0) were detected, respectively. For these traits the biasedness of the model was removed after elimination of one parent from the diallel table. Grain protein percentage was not analyzed as it necessitated the elimination of 2 parents from the diallel table. In general, regression of W_r on V_r compare to W_r + V_r and W_r - V_r analysis of variances showed to be a more valid inductive method for testing the accuracy of the genetic model assumptions. Also, results of the Hayman and Jinks analysis, both when the assumptions are valid and when not, showed that genetic parameters are affected by the biasedness of the model, and that different estimates will be obtained. The Griffing's method was less affected by the unbiasedness of the model than Hayman and Jinks method. Therefore, it seems that preliminary testing for validity of the assumptions is necessary in Hayman and Jinks genetic model.

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Any mechanical force exerted on a potato tuber during the harvesting may result in mechanical damage. A few weeks prior to harvesting, haulm destruction could improve the rheological properties of the tuber and reduce its susceptibility to mechanical damage. The effects of elevator and oscillatory sieve diggers and haulm destruction on potato loss and mechanical damage were studied on a farmer field in Fereidan region of Isfahan. Two haulm management treatments (destruction and non-destruction) along with five potato diggers (elevator digger with a long main web and with agitator, elevator digger with primary and secondary webs and with agitator, elevator digger with a main web and with/without agitator, and reciprocating riddle digger) were laid out in a strip block design within a randomized complete block design with four replications. The main crop variety, namely Marfona, was planted in the field.

The results showed that the percentages of undigged and soil-covered tubers were significantly different among the potato diggers tested. These losses were due to the dices located to the sides of shares or gage wheels and wrong adjustments on the diggers. Comparing the performance of reciprocating riddle with elevator diggers, its sieving capacity was low and the severity of the mechanical damage and the numbers of tubers covered with soil were high. Haulm destruction was effective in reducing the peeler type damage (the less than 3 mm deep damage to flesh). Although the elevator digger with a main web (elevator chain) and without agitator had the least mechanical damage index, the differences among the elevator diggers tested were not significant (5%).

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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.

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Soil development and variability of soil properties on different landforms of Central Zagros were investigated. The study area covers two climatic regions including Shahrekord and Chellgerd with mean annual precipitations of 314 and 1224 mm, respectively. In Shahrekord area, the amount of Fe_o (amorphous and organic-bound iron) was higher in surface horizons, whereas, the Fe_d (crystalline, amorphous and organic-bound iron) was higher in the surface soil of well-drained pedons and concentrated in subsoils with high ground water. Smectite increases as chlorite and palygorskite decrease. This might be an indication of Fe-chlorite transformation as a result of the local effects of organic acids, alternate oxidation reduction and hydrolysis intensity of a wetter past climate. Presence of an argillic as well as petrocalcic horizon with sparitic calcite and spherulitic fabric show intermittent and periodic leaching and deposition in Shahrekord area. Furthermore, reduction in sand and gravel content of the soils from mountain toward plains was attributed to the dissolution of carbonates and deposition of alluvium. Lower pH, lower carbonate content and higher pedogenic Fe in surface horizons were prominent in Chellgerd area. Consequently, interstratified chlorite-smectite, decrease of Fe-chlorite in fine clay, increase of smectite, high CEC and absence of petrocalcic horizon show that weathering intensity was higher in Chellgerd as compared to Shahrekord area. Also, papules with concentric fabric, higher Fe_d-Fe_o, and redder hues in buried horizon suggest polygenetic soils. There was some evidence of climatic change in two areas however, time seems to have played an important role in Shahrekord, whereas topography must have been more effective in Chellgerdarea due to higher tectonic activities and unstable landforms which may confirm the formation of the buried horizon and paleosols.

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This study utilized a descriptive-correlational surveying approach to examine some economic factors involved in the adoption of an integrated campaign to control rice stem borer (Chilo suppressalis) in Isfahan Province. The population consisted of farmers living in the vilages where Biological Control Plan was conducted (N=6000). The population frame was obtained from Isfahan Agricultural Organization. The sample was obtained using the cluster random sampling method (n=361). Questionnaire and interview were used for data collection in this study. Face and content validity of the instrument was established using a panel of experts consisting of senior faculty members in agricultural extension and education at Tarbiat Modaress University. Further, the agricultural officer of Isfahan Province validated the questionnaire. A reliability analysis was conducted and Cronbach alpha value was reported to be 83 percent. The results showed that the rate of adoption of Integrated Campaign to Control Rice Stem Borer among the farmers was moderate. Among the economic characteristics, there was a significant relationship between adoption of integrated campaign and area of land, amount of area under cultivation, degree of family cooperation in the agricultural activities, access to agricultural inputs, access to financial resources, and yield of rice per hectare.

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To obtain soil-moisture characteristic curve experimentally is time-consuming and usually subject to considerable errors. So, many investigators have tried to predict soil-moisture characteristic curve by different models. One of these models predicts soil moisture characteristic curve based on soil particle size distribution and bulk density. In this model, soil particle size distribution curve is divided into a number of segments, each with a specific particle radius and cumulative particle mass greater than that of the radius. Using these data, soil-moisture characteristic curve was estimated. In this model, a scale factor, α, is used which may be considered as a constant, or obtained by logistic or linear procedures. The average values of α for clay, silty clay, sandy loam, two loam soils, and two silty clay loam soils were 1.159, 1.229, 1.494, 1.391, 1.393, 1.253 and 1.254, respectively. For most conditions, soil particle size distribution curve is not available, but only the percentages of clay, silt, and sand could be obtained using soil textural data, which is not enough to draw a precise soil particle size distribution curve. In this situation, a precise soil particle size distribution curve must be initially developed on the basis of which the soil moisture characteristic curve can be predicted. In this study, using soil textural data of seven different soils, soil moisture characteristic curve of each was estimated. In these estimations, logistic and linear methods were used to obtain the α value. Then, the results were compared with those of measured soil moisture characteristic curve. For estimation of soil particle size distribution curve, two extreme values for soil particle radius, 125 and 999 m, were used. The results indicated that using particle radius of 999 µm is more appropriate. On the other hand, it was found that for clay, silty clay, and sitly clay loam texture, it is more appropriate to employ a linear equation to determine for estimating soil-moisture characteristic curve while the logistic equation can be more appropriately used for loam and sand loam textures.

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The vast and diverse rangelands of Iran require the selection of appropriate methods for grazing intensity measurement in the different vegetation types. Methods can be compared on the bases of time and budget as well as their accuracy. In this study nine methods of the utilization measurement were conducted on the E. ceratoides stands of Hanna exclosure Semirom, Isfahan province. The duncan multiple range test was used to compare mean utilization percentages obtained from the different methods, with paired cage method data was used as control group. Analytical Hierarchy Process (AHP) was also used to compare methods for accuracy, time and budget. The means from reference unite, twig length, production index, plant count and stem count methods had significant (p<0.05) differences compared with control group but were comparatively time consuming and more expensive than other methods. The height-weight method resulted in an estimate with no significant difference with the control group. This method was also fastest and least expensive among methods with the accurate results (p<0.05).

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The Drying process is one of the most important factors which are effective on the milling quality of rice and its economic value. In order to investigate the effect of dryer parameters on milling quality of rice and their relationships, one of the usual rice varieties (Binam) of Gilan province with an average milling quality and the initial moisture content of 20.5% was selected. Drying process was performed on the basis of a complete randomized design with 20 treatments and 3 factors including temprature (at five levels of 30, 40, 50, 60 and 70 °C) , air velocity (at two levels of 0.5 and 2 m/s) and final moisture content of paddy (at two levels of 10.5% and 14% on wet basis equal to 11.7% and 16.3% on dry basis respectively). Results of the experiments indicated that increase of temprature or air velocity reduces drying time but increases drying rate constant (K). It also revealed that decrease of final moisture content of paddy increases drying time significantly, but doesn’t have any significant effect on drying rate constant (K). Correlation test indicated that milling loss (breakage) has a negative relation to drying time and a positive relation to drying rate constant(K), however, bending strength has a positive relation to drying time and a negative relation to constant of K. Regression of qualitative properties of paddy including: milling loss (breakage) and the bending strength over drying time and constant of K revealed that drying time is a better criterion for predicting the mentioned qualitative properties.

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Dasht Yari plain is nearly 580,000 hectares which is under engraving gully erosion and unfortunately the gully development rate is increased in the recent decades. Satellite images may provide quick, extensive, and valuable information for the interpretation of morphometric characterstics of gully erosion expansion due to having attributes such as time series, relatively low cost, large coverage, and finally being capable of digital analysis. Therefore, this research was initiated to use these possible capabilities to find a quick and cost effective method to determine the morphometric characteristics of gullies with use of the Landsat ETM⁺ digital data of Dasht Yari plain in Chabahar county in southeast of Iran. The Landsat 7 data of 2001 and the field data collected from 25 selected gullies from the same area were used as control in this study. After geometric and haze corrections with use of spectral enhancement methods such as linear enhancement and color composites, the images were made ready for visual interpretation and selection field sites for the subsequent field sampling. On the selected 25 gullies, the field data collection including width, length, and height of gullies at 25%, 50%, and 75% cross sections was performed. At the end of the image processing, with use of image interpretation techniques such filtering, fusion and principal component analysis (PCA), morphometric characteristics of the gullies was computed and compared with the field data. Mean comparison and F and t-student tests were used to verify any statistical differences between two set of the data. The results showed that the data set were different at 1 and 5 percent levels. From the image processing methods, the PCA method had the smallest difference with the field collected data. Therefore, we may conclude that PCA method may be used for monitoring the gully expansion in the Dashat Yari plain and similar plains in the southeast of Iran.

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Relationship between grain filling rate , grain filling duration, yield components and other physiological traits of rice was investigated in 93 genotypes of rice at Rice Research Institute of Iran (Rasht, Iran) during the growing season of 2001-2002. The experiment was performed without any statistical design. Panicles of main stem were tagged and taken at 3- day intervals during the grain filling period. A cubic polynomial model was used to fit the grain dry weight data (mean of R²= 0.98 for all genotypes) and the grain filling rate and duration estimated for the genotypes. Traits related to sink capacity such as grain weight, grain size and grain number per panicle correlated with grain filling rate but source -capacity- related traits except chlorophyll content of flag leaf and secondary leaf did not correlate with grain filling rate. Stepwise regression showed that final grain weight, grain filling duration and flag leaf angle contributed to grain filling rate, however, path analysis showed that only final grain weight and grain filling duration had the greatest effect on grain filling rate. The results of stepwise regression irrespective of final grain weight showed that chlorophyll content of flag leaf, grain width, grain filling duration and grain length contributed to grain filling rate. Path analysis results showed that the final grain weight had the greatest direct positive effect on grain filling rate, while grain filling duration had negative effect on grain filling rate.

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  Soil particle size distribution and bulk density are used for estimating soil-moisture characteristic curve. In this model, soil particle size distribution curve is divided into a number of segments, each with a specific particle radius and cumulative percentage of the particles greater than that radius. Using these data, soil-moisture characteristic curve is estimated. In the model a scale factor, a , is used which may be considered as a constant, or obtained by logistic or linear procedures. F or most conditions, soil particle size distribution curve is not available, but only the percentages of clay, silt and sand could be obtained using soil textural data. In this situation, at first a precise soil particle size distribution must be developed, based on which the soil-moisture characteristic curve can be predicted. According to the previous studies, using particle radius of 999 µ m is more appropriate than radius 125 µ m. Also, adjusted coefficients for estimating soil particle size distribution curve for radii 1 to 20  µ m was obtained. In this study, using the soil textural data of 19 different soils from UNSODA database, soil-moisture characteristic curve of each was estimated with logistic and linear methods based on initial and adjusted soil particle size distribution estimation. The estimated values were compared with the measured data. The results indicated that for most soils, using the combination of logistic and adjusted particle size distribution estimation procedures is more appropriate than the previous methods.

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Total petroleum hydrocarbon (TPH) contaminations in soils may be toxic to human, plants and cause groundwater contamination. To achieve maximum TpH- reduction and to establish successfull stable vegetation cover in phytoremediation method, various criteria must be considered to choose the plants carefully. In this study, germination and subsequent growth of seven plants were tested in three soils with different petroleum contamination levels. Contamination treatments consisted of C₀ (uncontaminated soil), C₁ (1:1 w/w, uncontaminated: contaminated soil) and C₂ (1:3 w/w, uncontaminated: contaminated soil). The experimental design was completely randomized split plots with three replications per treatment. The results showed that the presence of TPH in the soil had no effect on seed germination of agropyron, white clover, sunflower and safflower although canola seedlings were sensitive to these compounds and failed to produce dry matter yield (DMY) at the end of trial period. In contrast, seed germination of canola, puccenillia and tall fescue decreased in the petroleum contaminated soils. No reduction was found in DMY of puccenillia in contaminated soils (C₁ and C₂ treatments) compared to control however, the presence of TPH proportional to the contamination levels, decreased dry weight of sunflower and safflower. This reduction in growth and dry weight for tall fescue and agropyron was also observed in C₂ compared to C₁ treatment. Therefore, it seems that though agropyron, white clover, sunflower and safflower germinated well and the presence of TPHs in the soil treatments had no effect on their seed germination, they grew poorly. In contrast, grasses had poor seed germination but their subsequent growth and establishment in the contaminated soils was acceptable for subsequent phytoremediation trials.

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Determination of landscape evolution is useful to well understand the physical environment and it also enables us to conduct the soil related studies. The objective of this study was to establish the historic evolution of Zayandeh-rud Valley from late Tertiary to Quaternary. To achieve this objective, the spatial structure of a representative area of Zayandeh-rud Valley in three dimensions was examined. Responsible geologic and geomorphic processes of landscape formation were determined and inherited records and evidences of changes in soil development were investigated. The inherited foot marks and different analyses proved that following the Zayandeh-rud River formation, from Miocene to present time, the following processes and events have occurred during valley formation pathway: 1- formation of old gypsiferous gravelly alluviums, 2- lagoon formation, the change in the river pathway, 3- playa formation, 4- river terrace deposition and 5- starting of wind erosion.

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One of the most important cost factors in forest management, which involves a great deal of investment costs, is road construction. So evaluating forest roads and determining the best one can decrease costs. The objective of this study was to evaluate forest roads using Multi Criteria Evaluation with respect to costs. In Multi Criteria Evaluation method such factors as slope, aspect and soil type were used for suitability map. Then factors were compared in pair-wise comparison in the context of a decision-making process known as the Analytical Hierarchy Process (AHP) to develop weights of map layers. To do this, the opinions of some experts were collected using questionnaires and the results were integrated and factor weights were calculated. Then weights and their factors were entered into Multi Criteria Evaluation (MCE) Module to create final suitability map (factors were standardized before combining). Total costs of each variant were extracted from suitability map. After variant costs were obtained by dividing each variant total cost by its length, unit cost of each variant was calculated. Finally, unit costs were compared and the variant with the lowest costs was determined. The results showed that the slope had the greatest weight followed by soil and aspect. Also, variant 7 had the lowest cost and variant 8 the greatest cost. AHP method has the capability of considering qualitative and quantitative criteria so it is a proper method for weighting. Also MCE method in GIS environment has the capability of combining different factors. As it requires less time and cost, also has a higher precision, it is better to use MCE method in such studies.

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This research was carried out taking into consideration the defects of traditional process in and the most important factors affecting production of rock candy. Selected parameters used for effluent and rock candy consisted of supersaturation at 4 levels (1.3, 1.4, 1.5, and 1.6) and temperature at 3 levels (70, 80, 900C) with 3 replications. The physiochemical tests consisted of pH, color and invert sugar percentage done on all the samples. According to the results, the rise in super-saturation and temperature had significant effect on all the effluent and rock candy characteristics (P<0.01) such that color and invert sugar percentage increased and pH decreased as super-saturation and temperature increased. Furthermore, the interaction effect of super-saturation and temperature on pH, color and invert sugar percentage of rock candy was significant (P<0.01).

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Land and its size are important as the most basic factors of production in agriculture .Fragmentation is one of the main problems that rice producers of Mazandaran province are confronted with. Non-efficiency in farm management, inability in effective using of agriculture technology and machinery, and low range productivity of production are all related to land fragmentation. In order to overcome the problems and consequences originating from land fragmentation, specialists recommend the logical solution of land consolidation process, which is a basic strategy for changing the farm size. The purpose of this research was to identify and determine effective factors in land consolidation adoption by rice producers in Mazandaran province by using Logit Regression model. In this study, 150 rice producers from 5 villages have been investigated since 2007. Results show that variables of education, land quality, fragment distance and extension effort (learning programs) are the most important factors in land consolidation adoption by rice producers in this province (Sig=1%) . Also, number of the household and credit support are the next factors affecting in land consolidation adoption (Sig= 5%). I t must be noted that other variable such as age, farmer’s income, children education, experience of rice producers, cultivation area, membership in cooperatives, land situation, number of pieces and technical supports were not significantly involved.

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This study performs trend analysis of hydroclimatic varibles and their possible effects on the water resources variability. Nonparametric Mann-Kendall and spearman tests were used to investigate trend analysis of mean annual and 24-hr maximum rainfall, flood and low flow parameters of 23 hydrometery and 18 synoptic stations in Sefid-Roud basin. The results showed that mean annual and 24-hr rainfall parameters are decreasing in few stations while most of stations representing negative trend for low flow and flood time series. Applying Sequential Mann-Kendall test revelad that this negative trend is started from 1965 to 1970 for rainfall parameters and from 1970 to1980 for flow (low flow and flood) parameters. Results show that climate change has probability affected variability of climatic variables, while changing of land use may have aslo affeteced extreme flow trends during recent decads. Therefor it can be noted that combination of climate chanege effects and human activities on water recources have affected the negative trend of hydroclimatics variables.

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The aim of present research is landslide hazard zoning using Bayesian theory in a part of Golestan province. For this purpose, landslides inventory map was created by landslide locations of landslide database (392 landslide locations). Then, the maps of effective parameters in landslide such as slope degree, aspect, altitude, slope curvature, geology, land use, distance of drainage, distance of road, distance of fault, stream power index (SPI), sediment transport index (STI), and rainfall were prepared in GIS environment. Relationship between effective factors and landslide locations were considered using Bayesian probability theory. In the next step, parameters classes weights were found and the landslide susceptibility mapping was achieved by fourteen modeling approaches (using whole parameters and deleting parameters one by one). The verification results by ROC curve and 30% landslide locations showed that the Bayesian probability model has 71.37% accuracy for the second approach of modeling in the study area.

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In order to describe soils polluted with hydrocarbons, the amount and distribution pattern of soil heavy metals (Ni, Cd) in soils were studied. Soil samples were taken from one of the western oil field of Iran. The field was naturally exposed to crude oil spillage into soil and consequently was environmentally polluted during the development, production, transportation and storage of crude oil. Sampling was started near the oil wells with maximum relative contamination and continued to the remote places based on grid sampling pattern. Samples were characterized by physicochemical analysis. The results revealed different levels of total hydrocarbons (from 0.12 to 2.99 mg/kg of dry soil), Ni (from 32 to 136 mg/kg. of dry soil) and Cd (from 0 to 4mg/kg of dry soil). In addition, the role of soil agents such as pH and EC and sedimentary indexes was considerable in controlling the pollution trend in the studied area. Finally, by interpolation module and prediction of unknown values via Kriging techniques, the expansion plans were created. The extracted plans obviously illustrated the decrease in the levels of pollution indexes with the increase in distance from the given centers of pollution

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Check dams are considered as main measures for flood and sediment control in watersheds, and their uses have been rapidly increased from 1990 onward in Iran. This research is done in Darjazin watershed in north of semnan city. The check dams have been constructed from 15 years ago in two sub basins of the watershed for flood control in Mahdishar. More than 650 check dams were evaluated for effects on flood. The collected data in the field was fed to ArcGIS software. The effects of these structures on flood reduction were evaluated by HEC-GeoHMS extension and HEC-HMS model. Because of homogeneity of watershed management projects in the basin due to building more check-dams in different watercourses, any flood discharge is related to check dams. Evaluating the effects of check dams on flood by t-test showed significant differences between flood discharge before and after construction of check dams at 5 percent level. So, check dams have been able to reduce flood discharge by 16.7 percent on average.