JWSS - Journal of Water and Soil Science

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Different Extractants have been proposed to assess available P in different soils. Olsen method is widely used to determine available P in calcareous soils of Iran. However, it has not been compared adequately with other extractants. The main objective of this experiment was to compare this procedure with some other methods. Thirty nine calcareous soil samples from Fars Province with different physico-chemical characteristics were examined for available P by nine extractants. Furthermore, the effects of four P levels (0, 50, 100, 200 µgPg^-1 soil) on growth, P concentration and P uptake by corn were studied in a greenhouse experiment using 20 soil samples. The results indicated that the amount of extractable P decreased in the order, anion-exchange resin > Colwell > Morgan > Olsen > Bray P₁ (1:50) > Soltanpour & Schawb > EDTA > Bray P₁ (1:7) > Water. The amounts of P extracted by all methods, except that by Bray method, showed significant correlation. However, the correlation coefficients between resin, Olsen, Colwell and water were higher than the others. Regression analysis showed that P extracted by all methods, except Bray, was affected by organic matter and native Zn. Moreover, P removed by Bray method was decreased with an increase in calcium carbonate equivalent. Correlation between top dry weight, relative growth and P uptake and P extracted by resin, Colwell, Olsen and water were highly significant. Although the correlation coefficients between growth parameters and P extracted by Morgan and Soltanpour & Schawb were significant, they were of lower magnitude. Plant phosphorus concentration showed significant correlation with P extracted by Olsen and Colwell methods. In general, resin, Olsen and Colwell methods seem to be appropriate extractants for available P in the present study. However, to select the appropriate extractants, more research is needed.

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

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

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The present study evaluates the influence of the El Ninio Southern Oscillation (ENSO) phenomenon on the cold season precipitation over Isfahan, Fars, Khuzestan, Chaharmahal-Bakhtyari, Bushehr and Kohgiluyeh-Boyerahmad provinces. The results indicate that the occurrence of La Nina events caused a 20% to 50% reduction in precipitation over Bushehr, Chaharmahal-Bakhtyari and southern Fars. The cold event did not change the total precipitation over the other parts of the region. In contrast to La Nina episodes, the occurrence of El Ninio events caused a 20% to 70% increase in rainfall in most of the study area. While the most highly wet conditions are related to the El Ninio events, the occurrence probability of the severe droughts has found to be low during such events. In association with La Nina events, the occurrence probability of severe drought was found to be low. Only in Khuzestan and southern parts of the Fars Provinces, this probability has increased to about 0.5.

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Distribution of Phytophthora species associated with stone fruits decline in Fars was investigated. Of 36 isolates of Phytophthora recovered, 23 were identified as P. cactorum (mostly from infected crown) from almond, apricot, and peach and 13 isolates of P. nicorianae from crown and basal stem of almond and apricot from different environmental conditions. The reactions of crown and root of 6- month–old local almond cultivars, i. e., Mamaee, Moheb-Ali, Talkheh e- Najafabad (Isfahan Province), Talkheh Sadeh, and Sang Talkheh Riz from Neiriz (Fars Province), peach cultivar bitter pit and apricot cultivar Hallander from Isfahan to a virulent isolate of P. cactorum were evaluated under greenhouse conditions. The inoculum of the pathogen was obtained by growing on vermiculate – hemp seed extract for 4-6 weeks and positioned around either crown or root system. Plant height, root and total weight of plants, lesion size, plant mortality, and percentage colinization of the pathogen on root and stem base were determined. The results indicated that almond cv. Mamaee was the most susceptible and almond cv. Talkheh-e-Najfabad, peach cv. bitter pit and apricot cv. Hallander were the most resistant rootstocks to P.cactorum. Comparative reactions of root and crown of various rootstocks to P. cactorum showed that although inoculation site (root or crown) in most cultivars was not significant to most characters measured, the interaction of cultivars × site of inoculation became significant for certain characters such as plant height, lesion size, root and total plant weight and mortality, indicating different reactions by root and crown to P. cactorum in some cultivars.

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The dissemination of Phytophthora spp. in the surface irrigation water was studied during 1993-94 in Marvdasht area and certain other parts of Fars province. Monthly the water samples were taken along 100Km of the Kor river 22Km up stream from the Doroudzan Dam to about 80Km down stream to Mardvdasht where Sivand and Kor rivers joined. The other sampling locations includede the Maeen river adjecent to the Dam, and the Sivand river from Dashte-Morghab to Mardasht. Few samples were also obtained from Shapour and Dalaky rivers and also from Yasouj and the Sisakht regions in Khkilueh and Boir Ahmad. The water temperature, pH and EC were measured and samples were assayed on the same day of the collection. The water sample was filtered through the two layers of the cheese cloth and about 1L was placed in a plastic container (30 × 20 Cm) 2-3C deep and 100 fresh citrus leaf disks (6mm dia) were also added and incubated at the room temprature. After 48hr, disks were collected, washed, blotted dry and plated on Phytophthora were collected, washed, blotted dry and plated on Phytophthora selective medium (PARPH). At least 50 disks were used in the 5 plates for each sample. The five to 8 boiled hemp seeds were placed on each growing colony and transferred to the distilled water, after 12hr for sporangium production. The Phytophthora species were idenified by their morphological characteristic and temperature requirement. Phytophthora spp. were present in the most rivers except the Shapour and Dalaky. The predominant species were non-popilate high temperature (above 35C) species mainly P. cryptogea and P. drechsleri. In some cases P. capcisi and the other unidentified species were also detected. Phytophthora spp. were present throughout the year but the lowest population was detected during winter months. The fluctuation of the phytophthora population and the other water microorganisms in the Kor river after shiraz petrochemical complex during the growing season was very high, but sometimes reduced to zero (perhaps due to the water pollution). No Phytophthora colonies were detected in the dam lake or in the most cases in the cement canals.

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In the present research, for the development of Fars province minimum temperature atlas, minimum daily temperature data of 20 evaporative stations of Fars Regional Water Organization and five synoptic stations of Fars Meteorological Organization were used. At first, two starting times were selected for all of the stations. The first was the first day of Farvardin for analyzing the spring frost and the secend was the first day of Mehr for analyzing the autumn and winter frost. Also, the temperature range of 0 to –1.5 was classified as mild frost or freeze, the temperature range of -1.5 to –3 as the moderate frost or freeze and temperature below –3 as severe frost or freeze. The data of minimum temperatures, the first and the last days in which the three temperature ranges occurred and the day of the lowest temperature based on the two starting times were recorded. The selected number of days (dates) were fitted to the distribution functions by SMADA software and the best distribution function was identified using the statistical parameter Root Mean Square. The best fitted distribution functions were Pearson type III and log Pearson type III. Then, based on the fitted distribution function, the number of days for the occurrence of the first and last frost and number of days for the occurrence of the first lowest temperature were determined at 50 and 70% probability levels. Finally, each of these occurrence dates was plotted with Surfer software using the geographical positions of each station (longitude and latitude) for Fars province. Based on these plotted maps, the best days of planting and harvesting of the crops can be determined throughout the Fars province.

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Evaluating different aspects of government policy in terms of their indirect and welfare effects has been always of interest. In this study, the effects of gauranteed purchasing policy on land under cultivation and yields of cotton, potatoes and onions were investigated in Fars province. For this purpose, a Nerlove model was applied to time series data of 1972-02 after testing their stationary to estimate the cultivated lands and yields functions of these products. The use of protection rates as explantory varrables is one of the interesting characteristic of such a model. Although the results were not similar for all the products, the indication is that the policy has not had significant influence on the land areas and yields of cotton, potatoes and onions. However, taking into account that the policy has been recentely commenced in Fars, and that the policy takes time to become effective, the policy may result in different outcomes in the long run.

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An experiment was carried out to investigate the effects of different levels of energy (2700, 2900 and 3100 kcal/kg) and protein (13, 14.5 and 16 %) on laying performance of Fars native hens during the first phase of production. Two hundred and sixteen 25-week-old native pullets were put into fifty four groups of similar live weight (994 ± 169 gr) of four chickens, which were randomly allocated to nine experimental diets. Each treatment was replicated six times in factorial CRD design (3×3). At each level of energy, three diets were formulated to contain three levels of protein (16, 14.5 and 13%). The diets were fed ad libitum for a period of 20 weeks (week 25-45). The treatments 1 with 3100 kcal/kg ME and 16% protein and 3 with3100 kcal/kg ME and 13% protein had less daily feed consumption than treatment 7 with 2700 kcal/kg ME and 16% protein (90.50 and 87.30 vs 101.20 gr respectively, P<0.05). The effect of energy levels on daily feed and energy consumption and feed conversion ratio was significant (P< 0.05). Feed conversion ratio for energy level of 3100 kcal/kg was significantly different from 2700 kcal/kg (2.85 vs 3.08 respectively). The effect of protein levels on uric acid content of excreta and daily protein consumption was significant (P< 0.05) and protein level of 16% was significantly differed from protein level of 13% (11.40 vs 10.50 gr respectively). The results of this experiment showed that it is preferable to use the energy level of 2700 kcal/kg and protein level of 13% during the first phase of production of Fars native hens.

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In this study wholesale prices of selected crops, namely, tomato, onion and potatoes in Fars province were predicted for various time horizons by using common methods of forecasting and artificial neural networks (ANN). Monthly data from September 1998 to June 2005 period were obtained from Ministry of Jihad-e Agriculture. For comparing different methods data selected from September 1998 to December 2004 were utilized, and latest six - month data were mainly used to monitor the power of prediction. The MAE, MSE and MAPE criteria were used for comparing the ability of different forecasting methods. Results of this study showed that ANN had the lowest error in prediction of prices for one - to three - month periods, but for six - month prediction, all forecasting methods were not statistically different.

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Sustainability of livestock production systems (LPSs) is of prime importance to the needs of human beings. From a sustainability point of view, an LPS is sustainable when it is environmentally nondestructive, economically viable and socially provides appropriate quality of life for producer and the whole community. Iran LPS is primarily based on traditional production systems. Therefore, an important issue for animal production in this country is the question of sustainability of traditional LPSs.The aim of this paper was to investigate and compare the sustainability of traditional LPSs in Firouzabad County. Three dimensions of sustainability were considered. Survey research was used to reach this purpose. Therefore, 300 livestock producers in “Nomadic”, “Semi-nomadic” and “Village- based” system were interviewed. Respondents were selected by a multi-stage cluster random sampling method. Face validity was confirmed by experts and the questionnaires were subjected to reliability testing using data collected in the pilot study. Findings showed that all three LPSs were unsustainable with regard to social, economical, and technico-environmental dimensions. Comparison of LPSs showed that Village-based LPS was from social dimension relatively sustainable and technically and environmentally unsustainable. While nomadic LPS was from social dimension relatively unsustainable and technically and environmentally sustainable.

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The Madden–Julian Oscillation (MJO) known as the dominant mode of tropical and extratropical intraseasonal variability has an important role in the coupled ocean-atmosphere system. This study investigates the eastward propagation of the MJO and its impact on monthly (February-April) maximum and minimum precipitation in Fars Province. The positive and negative phases of MJO were categorized for the period 1979-2002. The maximum and minimum values of monthly precipitation was then determined for each phase as well as for the entire length of records. The given results have indicated that, in February, both maximum and minimum precipitation during negative phase were significantly greater than the corresponding values during the positive phase. This implies that the enhanced February precipitation and flood events are associated to the negative MJO phase. On the other hand, severe water shotage in February was linked with prevalence of the positive phase. The results for April were mostly found to be similar to February except that minimum precipitation was not significantly associated to the positive phase. In contrast to February, minimum monthly precipitation in March was found to coincide with the negative MJO phase. Maximum precipitation, however, could coincide with neither of extreme phases of MJO.

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Magnetic susceptibility (χ) measurements are widely used for the evaluation of soil profile development. Fourteen soil profiles were studied in a relatively wide range of climatic conditions in Fars Province. Citrate-bicarbonate-dithionite (CBD) extraction and micro CT-Scan images were used to evaluate the source of magnetic susceptibility. The results showed that soil samples lost 23 to 91 percent of their magnetic susceptibility after CBD extraction (χCBD), reflecting differences in the source (pedogenic or lithogenic) of magnetic susceptibility. Greater values of the decrease were noticed mostly in well developed soil profiles as well as in soil surface. 22 to 89% of the decrease was observed in frequency dependence of magnetic susceptibility (χfd) after CBD extraction. A significant positive correlation (P<0.01) was obtained between χCBD and χfd in the soil studied. Micro CT-Scan images with a spatial resolution of 33 µm showed lithogenic magnetic Fe oxide (magnetite) grains.

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Optimum allocation on inputs is more difficult when there are several objectives in agriculture activities. For this, it is necessary using methods that several objectives approximate to ideal point simultaneously. IN addition, no attention to farmer preferences in farm planning causes the troubles for farmers in accepting planning. So in present study it is tried to attention these subjects with using interactive multiple criteria decision making, in farm planning for Fars province. Maximization gross margin, minimization risk and, irrigation water selected for planning objectives. Results indicated that interactive cropping pattern is convenient to present pattern rather than compromise method. In interactive cropping pattern, risk decreased compare to present and compromise cropping pattern that it is indicated tend to risk diminish in region farmers. In addition, the results designated that interactive models have the results better than multi objective and compromise programming because to be attention to farmers preference. With attention to research finding can say that it is possible for reformation of values three objective maximization gross margin, minimization risk and irrigation water rather than present cropping pattern.

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The Madden Julian oscillation (MJO) is known as the primary mode of large-scale inter-seasonal variability in tropical regions, affectimg equatorial and sub-tropical climates. This study investigated the effects of the MJO on the occurrence of wet and dry spells in Fars province, central southern part of Iran, during November-April. Monthly precipitation data of nine stations spread over various parts of the province was analyzed during 1979-2005. Using two well-known MJO indices: MK and WH, the positive and negative phases of the MJO phases (enhanced and suppressed convective activity over the equatorial Indonesian region, respectively) were identified for monthly and seasonal scales. Precipitation-MJO composites were then constructed for the opposite phases. It was shown that for all the considered stations, seasonal precipitation during negative MJO phase was significantly greater (from about 2.5 to 6.0 folds) than the corresponding values during the positive phase. Moreover, the applied statistical tests proved that the frequency of wet or dry events was related to the prevalence of negative or positive MJO phase, respectively. As the positive MJO phase was engulfed, the probability of dry events varied from 60% to 84%. On the other hand, the probability of wet events was found to vary from 60% to 76% during the MJO negative phase.

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This study was carried out to investigate zinc (Zn) and cadmium (Cd) concentration in paddy soil and rice grain produced in central and southwest Iran in relation to soil and plant factors, and their intake in peoples diet was also assessed. Rice crops and associated surface soils (0-30 cm) were collected from 136 fields in Isfahan, Fars and Khuzestan provinces. The result, showed the DTPA-Zn concentration in more than 50% of paddy soils was less than its critical deficiency concentration (2 mg kg-1). The grain Zn concentration in more than 54% of the rice samples was less than 20 mg kg-1. The measured Cd concentrations in paddy soils and edible part of rice exceeded the world health organization (WHO) value in more than 12% of the samples. By considering the average daily rice consumption of 110 g per capita, the Zn intake from rice consumption was estimated about 10% needed for female and male adult. Diet intake analysis did not indicate any excessive dietary intake of Cd when Cd mean of concentrations in rice grain was 0.04 mg/kg, but based on the results of risk analysis, it is more than safely level for contaminated rice.

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Water scarcity is a major and structural problem in arid and semi-arid regions across the world that greatly concerns environmental policy-makers. The problem of adjusting the demand exceeding the sustainable supply has been mainly tackled with demand policies, particularly through investment in water saving technology and promotion of irrigation efficiency programs. However, there have been very few evaluations of these programs and many of those that exist raise serious doubt about the programs’ effectiveness in reducing the consumptive use of water, due to the occurrence of the rebound effect. In this study, a sample of 243 farmers in Fars province who have the sprinkler irrigation system installed in their farms was interviewed to collect needed data for investigating the rebound effect using AHP and ordered logit regression model. The results indicated that 74.5 percent of sampled farmers have experienced medium to large rebound effect. It was also found that the amount of dry and fallow land during installation of sprinkler irrigation system have a positive relationship with the probability of occurrence of the rebound effect. Finally, the results of this study can be used to determine the probability of the rebound effect occurrence after installment of the sprinkler system for farms where data is available. For example, in the farms with farm features 24, probability of the rebound effect as a result of water saving measures at the low, medium and high levels are 0.4, 32 and 67.4 percent, respectively. Therefore, we must apply specific water conservation and efficiency practices in such farms based on a combined use of technical, economic, social and political tools to reduce pressure on scarce water supplies.

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