IRANIAN JOURNAL OF AGRICULTURAL SCIENCES (JOURNAL OF AGRICULTURE)
Year:2008 | Volume:39 | Issue:1|Papers Count:27

Many citrus fruits of different cultivars become injured when exposed to low, but higher then freezing temperatures. In this study, the role of methyljasmonate and methyl salicylate on reducing chilling injury and decay incidence in grapefruit and Thompson navel orange harvested from North and South parts of Iran (with different climates) was investigated. The results indicated that the grapefruit and Thompson navel orange produced from southern part of Iran (with higher daily temperatures) is more susceptible to chilling injury and decay when stored in low temperatures. The study also demonstrated that there is a considerable difference between north and south produced citrus fruits as for internal quality. Response of treated fruits to low temperature storage, demonstrated that there is a significant differences between qualities of treated, and untreated control fruits. Grapefruit and navel orange fruits treated with 24 mL.L -1 of methyl jasmonate and methyl salicylate had the minimum chilling injury and decay incidence after 6 and 8 weeks of storage in 2°C.

The effects of different budding methods (patch, chip and shield), budding time (June and fall) and budding conditions (greenhouse vs. field), percent taking of the buds callus formation and scion growth were studied in walnut (Juglans regia L.). According to the results, patch budding method had the highest percent of success in all conditions and at all times with 91% in June under greenhouse conditions. The least success in taking of buds was observed with chip and shield budding methods showing no success (0%) in fall budding and under field conditions. However, June budding under controlled conditions increased the shield and chip budding percent of success up to 31 and 19%, respectively. With some exceptions, the same results were also obtained with callus formation and scion growth, i.e. the highest values for these two attributes were observed in patch budding. However, callus formation did not vary between greenhouse and field conditions.Scion growth was observed to be the highest (10.2 cm length) in fall budding and under greenhouse conditions.

Nodulated chickpea root samples were collected from Lorestan & Kermanshah provinces fields. Seventy two nodulating bacterial strains were then isolated using YMA medium. Infection tests were carried out and a total of 60 effective strains selected as chickpea nodulating strains. Through implementation of protein electrophoresis technique the strains were grouped while at least 30 strains selected for further characterization. The isolated strains were identified on the basis of morphological, physiological and biochemical tests. Protein electrophoretic patterns of the representative strains were compared with those of the type strains including Mesorhizobium eieeri USDA3383T, M.mediterraneum ATCC51670T and M loti ATCC33669T which were then characterized with their phenotypic features analyzed through SPSS software. Results indicated that the tested strains could be placed in three different clusters, representing three separate species of: Mesorhizobium mediterraneum, M.cieeri and Mesorhizobium sp.

Sultanin is an important seedless grape cultivar with good growth, but sensitive to berry dropping. Stripping, girdling, use of hormones as well as essential elements for reducing berry dropping and to increase fruit set have been studied by some researchers. In this study the effect of cane girdling and boric acid foliar spray on fruit set were studied. Girdling was carried out at the time of flowering and color variation of cane bearing fruits while foliar spray with boric acid at concentrations of 0, 1500 and 3000 ppm being carried out at a week before flowering. Fruit set percentage, bunch length, berry length, berry diameter and berry weight were the traits considered. Results indicated that, girdling at flowering time and boric acid (1500ppm) application each separately had the highest effect on fruit set but their combination had no significant effect on this characteristic (p=0.01). Girdling and boric acid application had no effect on length and diameter of berries. Highest berry weight was obtained in boric acid application at a concentration of 3000 ppm.

A field study was conducted in Iran to evaluate the effect of water table management (WTM) on the yield of annual alfalfa (Medicago scatella). The WTM treatments consisted of three sub irrigation treatments with water table controls set at 0.3 m (CWT0.3), 0.5 m (CWT0.5), 0.7 m (CWT0.7) from the soil surface and a free drainage (FD) treatment (water table more than 1.00 m below soil surface). Crop yield was higher in CWT than in FD. Alfalfa yields in the CWT0.3 and CWT0.5 treatments were 73.5% and 94.3% respectively greater than in the FD treatment. Yield increases were attributed to greater crop water uptake in the CWT treatments as a result of higher water tables. Irrigation water consumption was lower in CWT than in FD resulting in higher water use efficiencies in CWT treatments. Water use efficiencies were 0.83, 0.97, 0.6, and 0.27 kilograms per cubic meter respectively in CWT0.3, CWT0.5, CWT0.7 and FD.

Ethylene as a plant hormone plays a major role in senescence, loss of fruit quality, and lowering of shelf life in apples, making the fruit unsuitable for consumption. Modified atmospheric packaging is the way that can control respiration rate of product through decrease in O2 along with increase in CO2 levels. In order to maintain quality and increase the storage life of 'Shafi Abadi' apple, an experiment was conducted in split factorial design with four replications. Treatments consisted of three different storage temperatures (1, 4 and 2S °C); gas combinations of two levels (the first one 2% CO2 - 3% O2 and the second one 4% CO2 -1 % O2) along with two types of polymeric films (polyethylene and polypropylene). Tissue firmness, TSS, EC, pH, TA, TSS/TA, and rate of ethylene production were measured and estimated every 14 days. The results showed that ethylene production rate at 1°C was lower and the packed fruits under 1°C with gas combination of 1 % O2 - 4 % CO2 and polypropylene film maintained TSS, TA, TSS/TA and tissue firmness as compared to other treatments. pH and TSS/TA of fruits showed an increased trend and TSS, TA decreased as well through the storage of fruits. The changes in quality factors occurred with a slower rate than in controls. The results indicated that modified atmosphere packaging has led to extension of storability and retardation of softening rate in fruits as compared to control.

Water scarcity along with its high demand in agriculture sector have arisen the attentions of many to manage and optimize irrigation systems. Among surface irrigation systems, furrow irrigation with cutback regime is a common system because of higher efficiency, lower costs, and lower demand of technical labor as well as more adoption to farmer's culture. This system is affected by management and design parameters, and hence different management scenarios should be evaluated before being applied in practice. To this end, empirical functions of evaluation performance indices become useful. This paper employs sensitivity, dimensional and regression analysis to develop empirical functions of application efficiency (Ea), deep percolation (Dr), runoff (Rr) and uniformity distribution (Du) by furrow bed slope and flow cross sectional area and through the design and management of such variables as; inlet flow rate, furrow length and cutoff time. The proposed functions were evaluated by a numericalzero-inertiamodel. Determination coefficients of Ea, Dr, Rr and Du were calculated to be 0.90, 0.91, 0.90 and 0.84, respectively. These values indicate that the proposed functions enable one to satisfactorily estimate evaluation indices. The results of developed dimensionless functions showed a very good agreement with the outputs of a zero-inertia model as well as with field recorded data.

Loess sediments among of the most widespread forms of eolian glacial sediments. These sediments are usually yellow but grizzly with approximately 70 to 90 percent of their formation consisting of silt materials. Iran losses are mainly located in northeast regions. The purpose of this research is to investigate sediment logical properties of loesses in Ghapan (semiarid climate) and Naharkhoran valley (humid climate) regions in Golestan province. Loesses in mentioned sections were described based on soil taxonomy and from non-developed horizons of parent materials (C horizon). Grain granulometry at the 2 stages of measuring sand components, with the help of wet sieve, and also, a determination of silt and clay components, with the help of pipette method, where completed. The gained conclusions indicated that, in studied sediments median and mean diameters stand between 4 to 11 and 3 to 8 microns respectively. Also in these sediments, sorting, skewness and kurtosis are very poorly differenced, frneskewed and platy kurtic respectively. These sediments are not equable, the fine grains being abundant and sedimentation having occurred in quiet environments. The main part of inequality is related to particles with the medium size. The statistic conclusions indicate that the sediments found in Ghapan as compared with the ones found in southern Gorgan are significantly different in median and mean diameters, but these sediments are similar from the view point of skewness and kurtosis. Ghapan region loesses are coarser and with a better sorting. A comparison of the studied loesses sedimentary properties with those in a few other countries' losses indicated that there nearly exists a harmony between them from sorting and skewness aspects, but from the view points of median and mean diameters and kurtosis they are different. Weak sorting and granulometry curve bimodality, in these sediments, indicate that Iran loesses are of 2 origins of different distances. Also, the finer being of southern Gorgan section sediments as compared with Ghapan section, shows that, north and northeast winds (northeast - southwest) play an important role in forming Iran northeast losses.

In order to find the suitable pollinizers for 'Ohadi, 'Kalleh Ghoochi', 'Akbari' and 'Ahmad Aghahi' cultivars an experiment was performed in the Pistachio Research Institute, Rafsanjan, Iran, during 2004 - 2005.The experiment was performed and analysed as a randomized complete block design. Eight ghenotypes, originally from the progenies of seed-raised trees and with appropriate flowering overlap with these four cultivars, were selected for controlled pollination. Male flowers of P1 and P2 genotypes were in overlap with 'Kallehghoochi', P3 and P4 genotypes in overlap with 'Ahmad Aghaei', P6 and P7 genotypes in overlap with 'Ohadi' and finally P9 and P10 genotypes were simultaneous in flowering with 'Akbari' prior to blooming, chosen limbs on the female trees were isolated and covered, using pollen impermeablecloth bags. At blooming, pollen from each of the pollen sources were injected into the bags using syringes. Fruit set, blank nuts, unsplit nuts, split nuts, kernel weight and fruit weight were recorded at the harvesting time. Also the percentages of pollen germination, inflorescence weight and amount of pollen per inflorescence were recorded. Results showed that P1 and P2 genotypes were the suitable male genotypes for 'Kalleh Ghoochi'. The amount of pollen per inflorescence in the PI genotype was more than that in P2 genotype, but germinated pollen percentage, fruitset percentage, split nuts percentage, blank nuts percentage, kernel weight and fruitweight did not show any significant difference between P1 and P2 genotypes. With no significant difference between PI and P2 genotypes, P2 genotype was observed to be better than plgenotype in the assessed factors; therefore more research is needed to pick out the most suitable genotype. P3 genotype was selected as the suitable male genotype for 'Ahmad Aghaei', because split nut percentage was more than that in P2 genotype. The amount of pollen per inflorescence and germinated pollen percentage did not reveal any significant difference between P3 and P4 genotypes. Also fruit set percentage, blank nut percentage, kernel weight and fruit weight did not show any significant difference between P3 and P4 genotypes. P6 and P7 genotypes were selected, as the suitable male genotypes for 'Ohadi' . Pollen per inflorescence and germinated pollen percentage for genotype p6 were more than those for P7 genotype, but as for traits fruit set percentage, split nut percentage, blank nuts percentage, kernel weight, and fruit weight there was not any significant difference observed between P6 and P7 genotypes. With no significant difference observed between P6 and P7 genotypes, P7 was shown to be superior to p1 genotype in the assessed traits. Thus, more research is needed to finally find out the most suitable genotype. P9 was selected as the suitable male genotype for 'Akbari' because the pollen amount per inflorescence, kernel weight and fruit weight were more than those in P10 genotype, but as for the traits germinated pollen percentage, fruit set, split, and blank nuts percentages there was not any significant difference observed between P9 and P10 genotypes.

The use of moldboard plow in our agricultural system has been encountered with two problems: I) the possibility of plow pan formation which could have negative effects on vertical water movement into the soil and 2) low penetration rate. It was hypothesized that by cutting part of the surface (making serrations on the plowshare) and equipping the plowshare with a separate SharePoint; it would lead to solving the two aforementioned problems. The results of the first part of the research, related to the measurements of water infiltration, showed that serrations on the plowshare could prevent plow pan formation and significantly increase the infiltration of water. In this paper, the effects of serrations on the plowshare and equipping the plowshare with a separate SharePoint on the plow as well as tractor performance are reported. Hence, the effects of five plowshare types (deep-suck share (control), trapezium-shaped share with/without SharePoint, and serrated share with/without SharePoint) under two soil moisture contents (0.85 and 0.55 plastic limit (PL)), and two plowing depths (15 and 20 cm) on draft, specific draft and drawbar power requirement of the moldboard plow as well as the distance traveled by the plow to reach a stable depth, and on the slip of drive wheels, travel speed and tractive efficiency of the tractor in a silty clay loam soil (using a split-split plot arrangement in a randomized complete block design with 3 replications) were assessed. When soil moisture content was reduced from optimum value for plowing(0.85PL) to dry condition (0.55 PL); the slip of the drive wheels more than doubled, while only the draft of plow with deep-suck share equipped with SharePoint significantly increased (by 28%). Increasing the plowing depth by 33%, draft, drawbar power and slip significantly increased by 33, 48 and 23%, respectively; whereas the specific draft, with an average of 4.6 N cm-2, did not significantly differ. Plowing under dry soil conditions and equipping the share with SharePoint did not significantly reduce the distance traveled by the plow to reach the stable depth, while plowing under optimum moisture content, and equipping the serrated share with SharePoint reduced the distance significantly. Results showed that serrations on the plowshare did not significantly increase draft and drawbar power requirement of the moldboard plow as compared with other plowshare types.

Soybean mosaic virus (SMV) occurs in all soybean- producing regions worldwide. The damage due to infection by SMV vary, depending on the host cultivar, strain of the virus, and environmental factors. An introduction of soybean resistant cultivars is possible through knowledge of the kind of virus strain prevalent in a region. In this study, efforts were made to detect SMV strains in Mazandaran and Golestan provinces. During June, July and August 2002, 253 samples suspected of being infected with SMV were collected from various soybean fields in these provinces. By serological tests (ELISA, Dot-Blot, and TPIA), 147 samples were found to be infected with SMV. Following biological purification, based on different kinds of symptoms, 47 isolates were selected for further studies. These isolates were classified into four groups (I, II, III, IY) based on reactions of inoculated differential soybean cultivars (Buffalo, Davis, Kwanggyo, Marshall, Ogden, and York). Group-I did not infect any of the resistant cultivars. Two cultivars (Marshall, Ogden), four cultivars (Davis, Marshall, Ogden, York), and three cultivars (Davis, York, Kwanggyo) were infected by SMV groups-II, III, and IV, respectively. Results indicated that identified groups, I, II, III and IV, belong to strains SMV-G1, G3, G4 and G5 [described by Cho and Goodman (1979)], respectively. Two primer pairs (SMV-G2, G7) to prime the amplification of a fragment in the coding region of cylindrical inclusion protein were used in RT-PCR assay for differentiation of strains. All strains produced a 277- bp using SMV-G7 primers. But no fragments were amplified from RNA extracted from any of the strains using SMV-G2 primers. RT-PCR confirmed the results of differentiation of strains based upon reactions of inoculated differential host.

Sulfur is one of the essential elements needed for plant growth and development. In addition, it has been used for disease control as well as for pH reduction in alkaline soils. The chemical oxidation of sulfur in soils is generally very slow. Microbial activity of some microorganisms in soils could enhance the process of oxidation of sulfur, which eventually results in pH decline. A variety ranges of heterotrophic microorganismsplay role in sulfur oxidation, but their role is unclear in the different ecosystems and it is possible that the role of heterotrophic species, could be more important than chemolithotrophic ones in some special cases. Heterotrophic microorganisms with growth in different pH, range are classified into two groups of: acidophilic and neutrophilic. The objective of this study was to investigate the effect of organic matter and sulfur on the population of sulfur oxidizing heterotrophic microorganisms. Two soil samples containing acidophilic and neutrophilic heterotroph microorganisms, with a high pH along with different sulfate and CaC03 contents, were selected. The following four treatments were tested: time in days following the start of the experiment {0(T1), 10(T2), 20(T3), 40(T4) and 80(T5)}, soil {Takestan (S1) and Ajabshir (S2)},organic matter {0(O1) and 1.5%(02)} and sulfur rates {0(G1) and 0.2%(G2)}. At five stages of the experiment, samples were taken from pots for chemical and biological analysis (pH, EC, sulfate and the population of microorganisms).The results indicated that the population of acidophilic and neutrophilic heterotrophs was on the increase till 20th day, decreasing afterwards. Simple and interactionary effects of all factors on soil sulfur oxidizing microorganism’s reactionary soil´OM, and OM´S on heterotrophic acidophylic microorganisms by the simple effect of soil and the interactionary effect of O. M. xS on the population of heterotrophic neutrophylic S oxidizing microorganisms. An application of 1.5% O. M. increased the population of heterotrophic acidophylic and neutrophylic microorganisms by 166 and 265 percent respectively. An application of S too increased the population of the two groups by 20, 39%. There exists a close relationship between the population of S oxidizing microorganisms (heterotrophic acidophylic and neutrophilic) and soil pH. With an increase in pH their population decreases. Variation in population of 38 and 49 percent respectively is explainable with regard to soil pH.

Phytoremediation is a remediation technique that either involves plant uptake, transformation, accumulation, and / or volatilization of soil and aqueous-phase contaminant or acts by stimulation of microbial activity in the rhizosphere of the plant. In this study the effect of planting tall fescue (Festuca arundinaceous), alfalfa (Medicago sativa) on dissipation rate of total petroleum hydrocarbons (TPH) from soil contaminated with different levels of light crude oil was investigated. Tall fescue, alfalfa and a mixture of the two were planted in 800g pots of either uncontaminated or contaminated (1, 3, 5, 7 and 10 percent crude oil) soil, and kept to be grown in lab for 4 months. Soil samples from the phytoremediation experiments were collected at 0, 30, 60 and 120 days after the start of experiment and sorted at 4°C before being tested for the dissipation rate of TPH. The dissipation rate of TPH was significantly different in planted as compared with unplanted soil in all percentages of crude oil content. The highest decrease in TPH concentration occurred during the first month of growth. Dissipation rate of TPH decreased with enhanced oil concentration. The most dissipation was observed in soil with one percent of crude oil and that which was planted with a mixture of tall fescue and alfalfa (75.5%). The lowest dissipation (18.8%) occurred in unplanted soil contaminated with a ten percent of crude oil. In this study it was demonstrated that the dissipation rate of TPH was faster in planted soil than in unplanted soil, despite the fact that the difference between dissipation rates in planted and unplanted soil decreased with enhanced crude oil concentration. It is postulated that decreased dissipation rate in high crude oil concentrations is a result of decreased plant biomass.

Guaiacol - peroxidase (POX) activity was assessed spectrophotometrically in tomato (Roma VF : resistant to Fusarium oxysporum f.sp. lycopersici and susceptible to Meloidogyne javanica) roots inoculated with nematode or fungus alone, and in fungus inoculated roots preinoculated with nematode in four biological life stages of the nematode. Results showed that POX specific activity increased in plants inoculated with fungus reaching its maximum level at the 5th day while in nematode inoculated plants the activity of the enzyme increased only until the second day and then decreased. POX enzyme activity showed a significant decrease in treatments (nematode + fungi) as compared with the fungi inoculated control plants. Results showed that the nematode is able to changeor suppress induction of this enzyme even against fungi. Nematode in all its biological stages can suppress the induction of POX activity in tomato roots, but in young adult formation stage the suppression is more pronounced than in the other life stages of the nematode including giant cell formation, egg-laying and penetration. Native polyacrylamide gel revealed the presence of five isozymes of POX with relative mobility (Rm) values of 0.30, 0.40, 0.50, 0.51 and 0.65 in root extract after a specific activity of stain inoculated with fungus. Isoforms with Rm values of 0.30, 0.40 and 0.65 showed lower intensity in fungus + nematode inoculated plants as compared to inoculation with the fungus alone. Based on the results obtained in this study, nematode infection resulted in suppression of tomato defenses, reduced tolerance or resistance to fungus (as a secondary pathogen) and resulted in an intensification of the fungal disease.

Records of 3257 lambs of Zandi sheep breed, collected from 1991to 2003 in Khojir rearing and breeding station of Tehran province were used to estimate the genetic parameters for growth traits (birth weight, weaning weight, body weight at 6, 9, and 12 months of ages) along with composite reproduction traits (total weight of lamb weaned per ewe joined through three consecutive parities. Based on univariate analysis, the best model for birth and weaning weights was model 3 (including direct and maternal additive genetic effects). Modell (including direct additive genetic effect) was the most appropriate model for body weight at 6, 9 and 12 months of ages. According to this model, the direct heritability estimates for growth traits (from birth weight to body weight at 12 months of age) were 0.08±0.04, 0.20±0.05, 0.29±0.06, 0.25±0.06 and 0.35±0.07, respectively. Maternal heritabilities of 0.17±0.02 and 0.06±0.03 wares obtained for birth and weaning weights, respectively. Genetic parameters for composite reproduction traits were estimated using model 1. Heritability estimates of 0.06±0.08, 0.03±0.09, and 0.08±0.11 were obtained from first to third parity, respectively. Covariance components and correlations between growth and composite reproduction traits were estimated on the basis of multivariate analysis, using the most appropriate model in univariate analysis. The highest additive genetic correlation among growth and composite reproduction traits was obtained between weaning weight and TWW2/EJ (0.99). The corresponding estimate for additive genetic correlation among growth traits was 0.99 (between weaning and body weights at 6 months of age). The results of this study indicated that selection on the basis of weaning weight can improve the post weaning and composite reproduction traits.

Effects of bleaching, deodorizing and commercial lecithin on reduction of cholesterol level in beef tallow were studied. Beef tallow was obtained from a local slaughterhouse. Steam-rendering extracted fat was bleached and deodorized in lab. Deodorized fat was treated with commercial lecithin and the effects of four factors, namely: ratio of lecithin to tallow(1:5, I:10, 1:20 and 1:30), stirring time (0.5, 1.5,3, 6 and 12hr), stirring rate (200, 500, 1000 and 1250 rpm), and ratio of lecithin to water (1 :2, 1:5 and 1:10) were investigated. Bleaching and deodorization, reduced cholesterol content by 1.5 and 4.8 % respectively. Results indicated that cholesterol removal increased with increasing lecithin to tallow ratio and stirring rate. Increasing stirring time up to 1.5 hr increased cholesterol removal, however, longer times periods didn’t have any significant effect on cholesterol removal. Ratio of lecithin to water content didn't have any significant effect on cholesterol removal. Treatment with lecithin increased tallow acidity and color but didn't have any effect on peroxide value (p.V.). Since tallow being a slaughterhouse by-product and not expensive, so it is suggested to further enhance its consumption as an edible product through treatment with lecithin.

Limitations of water resources and the ever-increasing demand for this vital resource have intrigued water crisis along with its unpleasant consequences. Hence, conducting more accurate studies on water resources is of special importance. In this study, water resources and specifically, ground waters in different parts of east of Guilan province, have been studied, and some practical strategies regarding the shortage of water which is obvious in different sectors, especially agriculture, have been presented. For this purpose, some field and laboratory studies were done and then the results analyzed. Findings showed that there are two distinct regions of ground water with highly exploited aquifers. The first region is located in the south and southwestern parts of Roudsar and the second in the south and southwestern parts of Kelachay. In the map of iso transmissivity, these two regions include curves of more than 300 m2/day. This research also showed that the existence of salt water in some of the studied regions with shallow depth is not due to the entrance of the Caspian Sea's sub saline waters, but related to the fossilized salt water. That is why at times, one encounters salt water in shallow wells, which are occasionally artesian. Regarding a number of high discharge springs in the region, researches have been done that helped drawing the recession curves of Sefidab, Latak, and Leilakouh springs whose coefficients of recession curve ( a ), storage capacity (W) and discharge formulas are: For Sefidab spring(1999): a =3x 10-7, W=4.3 x 10-6m3 ,and Qt= 1.3 e-0.00000, while for Latak (2000) and Leilakouh(2003) springs: a =1x 10-7 , W= 2.3 x 106m3, and Qt =0.23 e -0.000000. Aquifers of the region include phreatic aquifers, under pressure and artesian. The studied ground waters are of suitable quality for drinking and agricultural purposes. Moreover, there are not any nitrate problems in aquifers and low BOD and COD values indicate the existence of healthy and clean waters.

Fixation of potassium in the main rice cultivated areas of North of Iran was investigated through collecting composite soil samples (0-30 cm depth) from 67 randomly selected paddy fields (one sample per field) scattered all across Guilan (33 fields) and Mazandran (34 fields) provinces. Twenty grams of air dried soil was transferred into a polyethylene tube (34-45 cm long x I cm diameter),then a known quantity of K as KCI solution and enough distilled water added to the tube until the depth of water above soil surface reached 5 cm. The tubes were incubated under this condition for 30 days, and then the amount of K fixation measured. The amounts of K fixation were between 4.9 and 65.1 percent, with a mean value of 27.4%. Potassium fixation in Guilan province was of a wider range (4.9-65.1%) than that in Mazandaran province (14.2-49.2%), however, the mean values (28% vs 27%, respectively) for the two provinces were not significantly different. It was estimated that, out of 470.000 ha of rice cultivated areas in North, about 98000 ha had a high (more than 40%), 218000 ha had a medium (between 20 to 40 %), and the remaining 154000 ha were of a low (less than 20%) potential for K fixation. The significantly high potential for K fixation of these soils is a result a gradual K depletion due to the disturbed input-output K balance in these soils. The amount of K fixation was significantly (5% level) correlated with coarse clay, silt+clay, total clay and CEC (r = 0.7), but it was poorly correlated with fine clay and silt content of the soils. In addition, it was revealed that in 54% of the soils, the ammonium acetate extractable K, which was assessed under wet conditions of 30 days after submergence, was below the critical level of 115 mg kg-1. as for rice. The low available K plus a high fixation rate prevailing in these soils, can cause serious nutritional problems for rice in these soils.

Anthropogenic release of heavy metals (HMs) has resulted in a continuous buildup of HMs in agricultural soils. Uptake of HMs by crop plants may lead to through food chain transfer to humans, and on the other hand, leaching of HMs through deep seepage may cause groundwater contamination. The objectives in this study were to assess the applicability of HYDRUS-ID code for simulating the mobility of Cd, Cu Pb and Zn under two common crop plants with different rooting systems (wheat (Triticum aestivum) with fibrous roots, and safflower (Carthamus tinctorious) with taproot) in the arid area soils of Isfahan, Iran. The study was conducted with undisturbed soil columns (Typic Haplocalcids) taken from a wheat and a safflower field located in the same unit of soil type. The top 10 em of the columns was artificially contaminated with Cd, Cu, Pb, and Zn at concentrations of IS, 585, 117 and 1094mg kg-1, respectively. A half of the columns were planted with wheat and the other with safflower according to the form's cultivation precedence. Leach ate was collected continuously. Following harvest of the crops, soil samples were collected at 10-cm depth intervals and analyzed for water-extractable metals. HYDRUS-lD code was employed to model metal transport in the soil columns as well as the metal uptake by plants. Model parameters were estimated through inverse modeling while using the SUFI-2 procedure. The results indicated that safflower resulted in larger metal concentrations at deeper depths than wheat. Metal concentrations were higher in drainage discharge of safflower columns as compared to those of the wheat columns. The simulation results obtained through HYDRUS-1D were acceptable except that adsorption constants were much lower than in the laboratory measured ones. This indicates that in HYDRUS-1D, the adsorption parameters were underestimated to allow for a deeper transport of metals, which had actually occurred due to in macropore flow in undisturbed soil. The results showed that HYDRUS-ID could well predict Cd, Cu and Pb uptake by wheat and Cd uptake by safflower. However, on overestimation of metal uptake by plants occurred when HYDRUS model simulation employed.

Vermicompost is considered as a biofertilizer with many physical, chemical and biological effects on arable cultivated solis. Vermicompost can be used in the production of many different products such as tomato, carrot, lettuce, cucumber, cabbage, and even com and wheat crops. The main purpose of this research was a verification of vermicompost and common compost as organic fertilizers for reducing or at least improving on the amount of chemical fertilizer consumption. For obtaining this goal, common compost and vermicompost were produced under similar conditions. Two replicates of cold compost and vermicompost in 3 levels of %1, % 2 and %3 were mixed with soil in separate pots and tomato (Lycopersicon sculentum, cherry) seedling transplanted into them. The results showed that plant height significantly increased in vermicompost treatments and biomass (dry matter) in vermicompost was also more than that for cold compost (P£0.01). Wet matter of plant tissues in vermicompost treatment showed a significant increase in comparison with cold compost. To some extent the amount of available Fe, Zn and Cu for all the cases indicated significant increase in vermicompost treatments (p£0.01).The vermicompost treatment with 60% cow manure had significant superiority in comparison with other vermicompost treatments. Thus, it was concluded that vermicompost with a higher fertility was of a better quality than cold compost.

Trinexapac-ethyle and paclobutrazol are routinely used to suppress clipping production and may have either positive or negative effects on turf grass response to drought. Growth inhibition with plant growth regulators (pGRs) has become an important practice in turf grass management. PGRs modify turfgrass growth by inhibiting either cell division or cell elongation. Phytotoxicity and root reductions have prevented widespread use of cell division inhibitors; therefore, gibberellic acid (GA) inhibitors are more frequently used due to less likelihood of leaf burn and turf grass injury. The objective of this study was to investigate the effects of exogenous PGRs application on turf performance and physiological activities of Kentucky bluegrass (Poapratensis cv Barimpala) under various drought treatments. Kentucky bluegrass seeds were planted at 60cm depth in PVC containers of 15cm diameters, filled with sandy-loam soil. The containers received adequate water until PGR application when they were irrigated at 3 different levels (at 2, 5, 10 day intervals). Paclobutrazol and trinexapac-ethyl were applied to separate containers at 0, 400, 600, and 0, 100, 200 gha-1 respectively. Trinexapac-ethyl was the PGR that enhanced turf grass quality during dry down in the natural condition. Application of trinexapac-ethyl not only reduced Kentucky bluegrass clipping production but also was effective in managing turfgrass growth. Paclobutrazol had negligible effects on poa quality and chlorophyll content, but reduced canopy height for up to 3 weeks. Kentuckey bluegrasses treated with any of the PGRs had rooting similar to that in the untreated turf.

One of the most important processes in environmental and hydrological problems and soil science, solute transport is simulated by different mathematical equations .Correct understanding of soil hydro-dynamical behavior in solute transport depends on exact parameter estimation of these equations .Different methods exist for estimation or determination of these parameters. In this study, 5 methods; Rifai et al (1956), Gupta and Greenkorn (1974), Elprince and Day (1997), Yamagushi et al (1989) and Hydrus-1D software (Simunek et al 2005) were evaluated to study of chloride transport in 20 topsoil samples obtained from different region of Iran. Solute transport experiments were done in steady state saturated conditions with Heaviside type top boundary condition at small columns of disturbed soil. Five different methods were applied to estimate the soil hydrodynamic parameters. The average soil water velocity and hydrodynamic dispersion coefficients were determined and compared. Results showed that the Elprince and Day method is the best parameter estimation method in according to proper estimations and fitness power.