JWSS - Journal of Water and Soil Science

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This study aims to evaluate land suitability for irrigated wheat in Falavarjan region (Isfahan) using the theory of fuzzy sets. This method differs from the usual land evaluation procedures in its use of weight for different land characteristics and in its method of determining land suitability index. The results were compared with those from parametric land evaluation method. The correlation between land indices and observed yield was higher for the fuzzy set method (r=0.35) as compared to the parametric method (r=0.14). The higher relationship given by the fuzzy set method illustrates its potential usefulness and applicability to land evaluation.

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In order to evaluate the relationship between SDS-sedimentation value and breadmaking quality of wheat (Triticum aestivum L.), glutenin subunits of different genotypes (foreign and Iranian cultivars) were analyzed by reverse-phase high performance liquid chromatography (RP-HPLC). SDS-sedimentation value was used as an indirect criterion for breadmaking quality.

 Correlation coefficients revealed a closer relationship between low molecular weight (LMW) glutenin subunits and variation in SDS-sedimentation value. Principal component analysis confirmed the presence of association between some of the glutenin subunits and SDS-sedimentation value. Based on the stepwise regression analysis, two LMW and four high molecular weight (HMW) peaks (subunits) were selected which accounted for 70.2 and 18.7% of variability in SDS sedimentation values, respectively. On the basis of the results of the stepwise regression analysis, a discriminant function was developed. The great efficiency of discriminant function in correct classification of completely different genotypes (Iranian landraces and cultivars) showed that the observed relationship between glutenin subunits and SDS-sedimentation value has a genetic basis and the effects of LMW and HMW glutenin subunits on SDS-sedimentation value are additive. Therefore, it seems that this method based on more protein components (rather than only on HMW glutenin subunits) can be used to predict breadmaking quality of wheat against many genetic backgrounds.

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A factorial experiment with two levels of Zn (0 and 1.5 mg Zn kg^-1), five salinity levels of irrigation water (0, 60, 120 and 180 mM NaC1, and 120 mM NaNO₃) in three replications was conducted. Wheat (Triticum aestivum cv. Roshan) was seeded in pots. After plant harvesting, zinc and cadmium concentrations were determined in the shoot. Activities of metal species in the soil solution were predicted using the computer program MINTEQA2. Treating the soil with NaC1-salinized water increased total concentration of cadmium (Cd_T) as well as Cd²⁺, CdC1⁰₂, and CdCl⁺ species whereas, NaNO₃ treatment had no significant effect on Cd_T. Shoot Cd concentrations were positively related to Cd_T and soil solution Cl^- but negatively related to Zn_T. Application of Zn-fertilizer decreased Cd and increased Zn concentrations in shoot, significantly. The results of this experiment showed that Cl^- has an effective role in increasing mobility of soil Cd and its uptake by plant.

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In a completely randomized design with 3×5 factorial arrangement, the metabolizable energy and nutrients digestibility of three varieties of sorghum grains (low, medium and high tannin) with and without supplemental phytase were determined and was compared with corn and wheat. Three varieties of sorghum were selected from the 36 varieties according to their tannin content and were grown togther with corn and wheat under the same environmental conditions. Supplemental phytase was added at three levels (0.0, 500 and 1000 FTU/kg) to each grain. The metabolizable energy (ME) and nutrients digestibilities were determined by the mature male Leghorn with the method of Sibbald. The results indicated that different grains had different ME, apparent and true digestibilities regarding dry matter, nitrogen and phosphorus. Medium tannin sorghum had the highest apparent and true metabolizable (AME and TME) energy, whereas the high tannin sorghum showed the lowest AME and TME. The apparent and true dry matter digestibilities of corn was more than the other grains (P<0.001). Medium tannin sorghum had the highest apparent and true nitrogen digestibilies than the other two varieties (P<0.001). Difference between tested grains regarding apparent and true phosphorus digestibilities were not significant. All measured criteria were the lowest for the high tannin sorghum. Adding 500 FTU/Kg phytase caused an improvement (P<0.001) in AME, apparent and true dry matter digestibilities and true nitrogen digestibility. Although added phytase improved apparent and true phosphorus digestibilities and true nitrogen digestibility, but the differences were not significant. The differences between 500 and 1000 units phytase was not significant and the results indicated that 500 FTU/Kg phytase was sufficient to improve the nutritional value of grains under study.

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Diallel analysis was used to estimate the combining ability, gene action, gene number, heritabilties and other genetic parameters of a set of wheat genotypes. For this purpose, nine parents and their 36 crosses were evaluated for 9 traits in a randomized complete block design with three replications in 1996. The analysis of variance revealed significant differences among all genotypes for all traits. Estimates of general and specific combining ability mean squares based on Griffing’s Method 2 indicated the importance of additive and non additive effects in the expression of all traits. Alvand and Roshan cultivars for grain yield per plant, Alvand for grain number per main spike and main spike weight, and Alvand and Alamoot for 1000 grain weight were the best combiners, thus use of them is beneficial for these traits. Based on the estimates of average degree of dominance and results of graphical analysis, the gene action for grain number and spikeletes per main spike were partial dominance, while for grain yield per plant, biological yield, plant height, harvest index and 1000 grain weight, overdominance gene actions were observed. Moreover, genotypic correlation coefficients of grain yield per plant with grain number per main spike, 1000 grain weight, grain weight per main spike and main spike weight were positive and significant.

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Sewage sludge application on farmland as fertilizer is commonly practiced in many countries. Sewage sludge is rich in macro- and micro- nutrients. However, high concentration of heavy metals in sludge may cause pollution of soil, groundwater and human food chain because of uptake of toxic metals by crops. The objective of this study was to determine residual and cumulative effects of sewage sludge on concentration of Pb and Cd in soil and wheat. Different levels of 0, 25, 50 and 100 Mg ha^-1 of sewage sludge were applied to the soil for four years. To study the cumulative and residual effects of the sewage sludge, applications were repeated on three fourth of each plot in the second year, on one half of plots in the third year and in one fourth of plots in the fourth year. Wheat grown in the plots, after the fourth year, soil samples from the 0-20 cm depth of the different parts of the plots were taken and analyzed. Wheat was also harvested roots, stems and grains were separately analyzed for the heavy metal concentritons. Cumulative sewage sludge application increased OM, CEC, ECe, total and DTPA-extractable concentration of Pb and Cd in soil significantly (P≤ 0.05). Residual sewage sludge in the soil also increased CEC, total and DTPA-extractable concentration of Pb and Cd significantly. Single sludge applications at different rates increased the DTPA-extractable concentrations of heavy metals. In subsequent years with no further sludge application, DTPA–extractable metal concentrations in soil decreased continuously approaching the levels in the control. However, even after four years, DTPA-extractable concentration of Pb and Cd, were still significantly higher in plots which received more than 50 Mg ha^-1 sludge than control. DTPA-extractable concentrations of Pb was closely correlated with total concentrations. Sewage sludge increased concentration of Cd in roots and stems and Pb in grains significantly. Cumulative effects on concentrations of Pb in grains, and Cd in stems were more than residual effects. The results of this study show that cumulative and residual effects of sewage sludge application increased concentrations of heavy metals in soil and wheat.

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Half diallel crosses of nine Iranian wheat cultivars were used to estimate the general and specific combining ability effects and other genetic parameters related to yield and its components. Parents with F2 generations were evaluated at Research Farm, College of Agriculture, University of Shahrekord, in a randomized complete block design with 3 replications. Partitioning of genotypes mean squares to GCA and SCA mean squares based on Griffing’s method 2 and mixed model indicated high significant differences among cultivars in their GCA values for all traits. There were significant differences among crosses in their SCA values for all traits except for flag leaf length, main spike length, plant height and grain yield per plant. The high ratio of GCA to SCA mean squares implied the importance of additive gene effects in the appearance of flag leaf length , main spike length, plant height and grain yield per plant. For flag leaf width, grain number per main spike and peduncle length , the contributions of additive gene effects and for peduncle weight, the contributions of non- additive gene effects were higher. According to the estimates of average degree of dominance, the gene actions for flag leaf length, flag leaf width, plant height, grain yield per plant, main spike length, peduncle length and peduncle weight were partial dominance. The GCA effects indicated that Sefid – Aliabad cultivar was the suitable general combiner for flag leaf length , flag leaf width, plant height , grain yield per plant , main spike length and peduncle length.

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The influence of Nitrogen (N) rates on mineral nutrient uptake in stem and seeds, proline and carbohydrate in flag leaves of Wheat (Triticum aestivum L . Var Chamran) under saline conditions was studied in a field experiment in 2003 and 2004. The experiment was conducted using a split plot design with three replications. The treatments comprised five levels of salinity: 1.5, 5, 10, 15 and 20 ds/m in main plot and three nitrogen levels: 50 , 100 and 150 kg N/ha in sub plot. Salinity treatments were applied in a clay–loam soil by water with NaCl and CaCl₂ (5:1 by wt ). The results showed, the nutrient uptake was influenced by both salinity and N treatments. With the Exception of magnesium in seed, salinity increased nitrogen, calcium and magnesium concentrations in seed and stem in both years. By increasing salinity levels, the concentration of potassium in stem and seed decreased and Sodium concentration increased. In the stem the concentration of Sodium in the 20 ds/m was about 17 and 22 times more in the first and second year, respectively. In these experiments, by increasing salinity and nitrogen treatments, proline concentration in flag leaves increased in the two stages (flowering and milky stages) in both years. Salinity had similar effect on carbohydrate accumulation in both stages, but nitrogen treatment had two different effects on carohydrate concentration. In flowering stage, by increasing nitrogen application, carohydrate concentration increased but in milky stage decreased.

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  This study was conducted at Research Farm of Isfahan University of Technology to evaluate drought tolerance potential of 23 F_2:4 wheat lines derived from the cross of Virmarin (susceptible line) and Sardari (tolerant line). A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3 and 120±3 mm evaporation from class A pan for non-stress and stress conditions, respectively). Drought tolerance and susceptibility indices were calculated for yield, and principal components analysis was performed on the basis of indices. Rosielle and Hambline tolerance index and Fisher and Maurer stress susceptibility index had positive and significant correlation, but their correlations with drought yield and the first two principal components were negative. High value of these components indicates low sensitivity to drought. The first component had high and positive correlations with geometric mean productivity, stress tolerance index and harmonic mean. Lines number 4, 17, 11 and 14 with high yields in drought condition, showed high values for these indices. Line number 2 with high yield in non-stress condition and in spite of high sensitivity to stress, was a superior genotype based on these indices.

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Water deficit, ultraviolet radiation and CO₂ concentration enhancement are three environmental stresses that affect nutrition of human in future. This research was conducted in the Research Greenhouse of Faculty of Agriculture, Tarbiat Modares University in 2006, in order to study leaf qualitative traits of durum wheat under different levels of carbon dioxide (400 and 900 ppm), ultraviolet radiation (UV A, B and C) and water deficit (up to %60 of field capacity). Ultraviolet radiation enhancement increased anthocyanin, flavenoids and carotenoids of durum wheat leaf. There was no significant interaction effect between carbon dioxide and water deficit on anthocyanin and carbohydrates. Also, the interaction effects among the three factors were not significant on anthocyanin, carotenoids, chlorophyll a and a+b. Water deficit decreased leaf proteins. Increasing intensity of ultraviolet radiation and carbon dioxide enrichment decreased soluble leaf protein in durum wheat under water deficit conditions. The results showed that three main environmental stresses which reduce leaf pigment and plant protection due to negative effects of these stresses along with soluble leaf protein reduction decrease qualitative and quantitative yield of the wheat variety.

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Kernel hardness is one of the most important characterizations on end-use quality of bread wheat and also used for their marketing classification. Kernel texture, mainly controlled by one major locus (Ha) located on the short arm of chromosome 5D. Two tightly linked genes as puroindolin a , and b covered by this major locus and designed as Pina and Pinb respectively. When both puroindolines are in their ‘functional’ wild state, grain texture is soft. When either of the puroindoline alleles is absent or alter by mutation, then the result is hard texture. In this study, 61 Iranian commercial cultivars and 92 landraces were investigated for their kernel hardness and puroindoline alleles using SKCS and, PCR and cleaved amplified polymorphic sequences (CAPS) techniques respectively. Specific primers were used to amplify Pina and Pinb. The results indicated that frequency of hard, mixed and soft genotypes were 65.6, 19.6 and 14.8% respectively, in commercial cultivars and 58.7, 13 and 28.3% in landraces varieties. Among hard type of commercial cultivars, 18 and 5, genotypes have identified as Pina-D1b and Pinb-D1b respectively. Kavir was only cultivar with Pinb-D1e allele. Pinb-D1b allele was identified in two hard types of landrace varieties. Surprisingly, Pinb-D1c was not found in any varieties. Influence of the above proindoline alleles on kernel hardness showed that the SKCS hardness index of Pina-D1b was significantly higher than that of Pinb-D1b. Our knowledge about the genetic basis of kernel hardness could provide useful information in breeding programs of bread wheat.

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Sewage sludge application on farmland as fertilizer is commonly practiced in many countries. Sewage sludge is rich in macro and micronutrients. However, high concentration of heavy metals in sludge may cause pollution of soil, groundwater and human food chain because of toxic metals uptake by crops. The objective of this study was to determine residual and cumulative effects of sewage sludge on concentration of Zn and Cu in soil and wheat. Different levels of 0, 25, 50 and 100 Mg ha-1 of sewage sludge were applied to the soil for four years. To study the cumulative and residual effects of the sewage sludge, applications were repeated on three fourth of each plot in the second year, on one half of plots in the third year and on one fourth of plots in the fourth year. Wheat was grown in the plots. After the fourth year, soil samples from the 0-20 cm depth of the different parts of the plots were taken and analyzed. After harvesting the wheat, roots, stems and grains were separately analyzed for the heavy metal concentrations. Cumulative sewage sludge application significantly (P≤0.05) increased the total and DTPA-extractable concentration of Zn and Cu in soil. Residual sewage sludge in the soil also increased the total and DTPA-extractable concentration of Zn and Cu. Single sludge applications at different rates increased the DTPA-extractable concentrations of heavy metals. In subsequent years with no further sludge application, DTPA–extractable metal concentrations in soil decreased continuously, approaching the levels in the control. However, even after four years, DTPA-extractable concentration of Zn in plots receiving more than 50 Mg ha-1 and Cu in plots receiving more than 25 Mg ha-1 sludge, were still significantly higher than control. DTPA-extractable concentrations of metals were closely correlated with total concentrations. Sewage sludge had a significant effect on concentration of Zn and Cu in stems and grains. Cumulative effects on Zn and Cu uptake by stems were more than residual effects. The results of this study show that cumulative and residual effects of sewage sludge application increased concentrations of micronutrients in soil and wheat.

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Performance of proper deep tillage can reduce negative effects of soil compaction. The objectives of the research were to determine the effects of deep tillage application on soil physical properties and wheat yield. Therefore, in 2006-2007 an experiment was conducted at Tajarak Agricultural Research Station of Hamedan on a soil with clay loam texture. In this research, four tillage methods were used. These methods were: 1) subsoiling with 30cm soil depth + conventional tillage (moldboard plowing) 2) subsoiling with 50cm soil depth + conventional tillage, 3) plowing by combined plow (chisel plow + roller) with 30cm soil depth and 4) conventional tillage (plowing by moldboard plow to 25-30cm soil depth). Randomized complete block design with four treatments and replications was used to analyze data and compare the treatment means. Before and after the application of the tillage treatments, parameters of cone index, bulk density and infiltration rate were measured in soil. Also before yield harvesting, components of yield (grain number in panicle, panicle number in plant and 1000 grain weight) were measured. To measure grain yield in experimental plots, in each plot ten square meter area from the yield was harvested. Result indicated that effect of different tillage treatment on soil resistance was not significant. Effect of deep tillage methods on bulk density and infiltration rate was significant. Deep tillage methods increased water infiltration rate in the soil and decreased soil bulk density. Effect of different deep tillage methods on wheat yield was not significant. However, application of chisel plow increased the wheat yield by 25%. It may be concluded the subsoiling treatment does not affect the crop yield in intensive and fully irrigated field condition. The results of this study indicated that if there is a compacted layer at 30cm soil depth, and with the same climate and soil as those in the experimental site, the application of chisel plow due to economical consideration (low fuel consumption and high field efficiency) can be recommended for soil preparation and cultivation of irrigated wheat.

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Application of sewage sludge has been considered as an organic fertilizer in arid and semi-arid regions of Iran. This study was conducted to investigate cumulative and residual effects of sewage sludge on soil inorganic fractions and their relation to phosphorus (P) availability. Two levels of application (50 and 100 Mg ha-1) and three consecutive times of sewage sludge application (1, 3 and 5 years) with a control treatment were studied in a randomized complete block split plot design with three replications. Composite soil samples were collected from 0-30 depth at the end of 5th year of application. Increasing the rate and application year of sewage sludge enhanced dicalcium phosphate (Ca2-P), octacalcium phosphate (Ca8-P), apatite (Ca10-P), aluminum phosphate (Al-P), iron phosphate (Fe-P) and available P but decreased occluded P (OC-P). Residual effect of sewage sludge application resulted in increased inorganic fractions in blocks treated for 1 year compared to control. Positive correlations were observed between inorganic P fractions and Olsen P, wheat yield and P uptake (except OC-P). We concluded that inorganic P fractions and P availability increased in sewage sludge amended soil.

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Environmental pollution caused by heavy metals such as lead is a serious and growing problem. Due to the importance of wheat in the human nutrition, this research was conducted to study concentration of lead in the soil and also seeds of wheat farms in Khuzestan Province. Therefore, in the agricultural year of 2007-2008, the soil and wheat seed samples were collected from 100 farms whose locations were specified using weighing sampling method. The lead concentrations in soil (total and available), and wheat seeds samples were measured. The result revealed that lead concentrations in soil and seeds in none of the studied regions exceeded the respective critical levels (50 and 30-300 mg/kg, respectively). Ezeh with an average of 0.01 µg/kg had the lowest amount of lead in the wheat seeds, while Bagh‌Malek with an average of 190 µg/kg had the highest amount. The mean concentration of available lead in the soils of study region was 0.6 mg/kg. The concentration of available lead had a negative and significant correlation (r=-0.2*) with the ECe. Also, lead concentration in wheat seeds had a positive and significant correlation (r=0.3**) with the amount of calcium carbonate equivalent. More lead concentration in seeds of bread wheat cultivars showed its higher potential for accumulation of lead than durum wheat.

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Organic fertilizers affect soil chemical and physical properties, particularly chemical forms of zinc in soil solid phase and thereby improve soil Zn availability. The present field study was aimed to evaluate the effects of organic and chemical fertilizer (zinc sulfate) on different zinc fractions in soil solid phase of rhizosphere in two successive years in Rudasht Research Field, Isfahan. Treatments consisted of sewage sludge (5 and 10 t ha-1), cow manure (5 and 10 t ha-1), and ZnSO4 (40 Kg ha-1). The control had no added Zn. Three weeks after applying fertilizer treatments, Back Cross genotype of wheat was cultivated in each plot. Our results showed that the organic fertilizers increased Zn concentration in exchangeable fraction (EXCH-Zn), the organically bound Zn form (ORG-Zn), and Zn bound to iron and manganese oxides (FeMnOX-Zn). However, the changes in Zn fractions were dependent on the fertilizer type. Positive and significant correlation between EXCH-Zn, ORG-Zn, and FeMnOX-Zn, and the total Zn uptake by wheat indicated that these pools of Zn in solid phase are labile pools with a significant role in supplying Zn for plants.

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