JWSS - Journal of Water and Soil Science

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The effects of three kinds of organic matter on the physical characteristics of two soil series (Coarse Loamy, Mesic, Typic, Xerofluvents and Fine Mixed, Calcixerollic, Xerochrepts) were studied along with the measurement of maximum dry bulk density (MDBD) and the corresponding critical moisture content (CMC). Soil samples were taken from a depth of 0-20 cm and the percentage of organic matter and soil texture were determined. Three kinds of organic matters (peat, farmyard manure and filter press apple) were mixed with the soils at four levels (0, 4, 8 and 12% by mass), and were compacted using 10, 20 and 30 proctor hammer blows. The compaction tests on soils were carried out at different moisture contents. The present experiment, using factorial design, was randomly conducted in three replications. The results of this study showed that while the mean MDBD declined significantly (P<0.01) from 1.53 to 1.28 gr.cm^-3, the mean CMC increased from 23.32 to 33.28% as the organic matter increased from 0.12%. In all the experiments, CMC decreased with increasing compaction efforts, so that the effect of mixed organic matter and soil in terms of MDBD reduction and CMC increase was decreasing in the order, peat, farmyard manure and filter press apple. The clay loam soil showed lower values of MDBD but higher values of CMC as compared to the sandy loam. The significant interaction effect observed between incorporation of organic matter and soil compaction were meaningful. Finally an equation as to the relationship between MDBD and CMC was proposed for the purpose of mixing the three organic materials with soil.

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In order to investigate the genetic diversity of morphological traits in 121 genotypes of lima, red and pinto beans, and to study the relation between characters, and to get better understanding of factors affecting the interaction between characters by multivariate analysis, an experiment was conducted in 1997 as a simple lattice design at the Research Station of Agricultural College, Isfahan University of Technology.

High variability was observed among genotypes for all characters studied. The phenotypic coefficients of variability were greater than the genotypic ones for all the traits. Among the characters studied seed yield, number of pods per lateral branches and main stem, length of lateral branches and main stem, number of nodes per lateral branches and main stem, 100-seed weight and number of lateral branches had the highest genotypic and phenotypic variability, while days to maturity had the lowest variability. Traits relative to lateral branches were more variable than the same traits in the main stem. Factor analysis for all the genotypes and, separately, for lima, red, pinto, determinate and indeterminate genotypes revealed 4 factors which justified more than 78.4 percent of the total variation. The results of the analysis based on all the genotypes showed that the first factor was mostly correlated to days to maturity, length of main stem and lateral branches, number of nodes per main stem and lateral branches, which was named “vegetative factor”. The second and third factors had the highest correlations with number of pods per main stem and lateral branches, number of seeds per pod in the main stem and branches and 100-seed weight, which were named “yield component factors”. The fourth factor showed the highest correlation with number of lateral branches and was named for this trait. The first and fourth factors were related to vegetative growth characteristics and physiological source. The second and third factors were related to physiological sink. On the basis of stepwise regression analysis, number of pods per lateral branches was the most important component of yield, and number of pods per lateral branches and main stem had the next following ranks. Number of pods per lateral branches and main stem had the highest relationships with yield.

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Iran with a cultivation area of 45000 ha and production of 150 ton/year is the number one saffron producer in the world. Planting of large size corms will increase flowering, but production of corms (number and size) may be affected by irrigation method or frequency. In this research which is performed in the farm of College of Agriculture, Shiraz University, the effects of method and frequency of irrigation on corm production, and the effect of produced corms on flowering were evaluated in two consecutive years. Two irrigation methods (basin and furrow) with four levels of irrigation frequencies (12, 24 and 36 days and dryland farming) were applied. In August of 2000 sample corm was taken from every plot, and the effect of applied treatment from previous growing period on corm production and the effect of produced corms on future flowering were evaluated and analyzed. Based on the results, in furrow irrigation, total number of corms and total number of corms smaller than 4 gr is significantly higher than basin irrigation. In all of the above cases, irrigation frequencies did not show a meaningful difference between themselves or in comparison with dryland farming treatment. Total weight of corms and number and weight of corms larger than 8 gr in basin irrigation were more than furrow irrigation. This is to the extent that it is considered as the main reason for the difference in the flowering of corms, and has caused the flowering of basin irrigation to be significantly higher than furrow irrigation. In basin irrigation, irrigation frequencies of 12 and 24 days had the highest amount of flowering. No significant difference was observed on average corm production between the treatments in the two irrigation methods. However, irrigation treatments in both irrigation methods showed significant differences when compared with dryland farming treatment. So, basin irrigation with irrigation frequency of 24 days is preferred over furrow irrigation due to lower water consumption and production of larger size corms which is effective in flowering.

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Irrigation water Scarcity is the major limiting factor for crop production in irrigated farming. Therefore, optimal use of water is influenced by seasonal rainfall especially where the water price is high. Nitrogen also plays a key role in plant nutrition. In this study, wheat grain yield production as a function of applied water (irrigation plus seasonal rainfall) and nitrogen fertilizer (applied plus soil residual nitrogen) using existing data of a field experiment, were used. This function was obtained based on the data from the Maraghah Agricultural Experiment station. Based on this production function, maximum attainable yield can be 8.12 t/ha obtained by the consumption of 1.56 m of water (irrigation plus rainfall) and 193 kg/ha of nitrogen. An economic analysis based on the Iso-Quant curve was conducted to optimize the application rates of production inputs (water and nitrogen). When land is limited, the optimum water and nitrogen use will be based on maximizing net returns from land unit area. The optimal levels of these inputs were determined on the basis of farmer ability for paying the costs of water and nitrogen. Furthermore, optimum amounts of water and nitrogen were determined for different levels of wheat yield. The results indicated that despite low price of irrigation water and nitrogen fertilizer, at present market value, optimum values of water were more variable than those of nitrogen, for its high effective role in wheat production. The results also indicated that when there is no limitation of the source and use of water and nitrogen, and farmers are also able to pay their costs, application of 1.47 m of water (irrigation plus rainfall) and 190 kg/ha of nitrogen (applied plus soil residual) will produce maximum profit per hectare, reaching Rls 12,207,506. When water is limited, optimum levels of water and nitrogen will be based on the maximizing profit per unit of water. In this analysis, the use of 0.556 m of water (irrigation plus rainfall) and 190 kg/ha of nitrogen (applied plus soil residual) resulted in maximum net income per unit of applied water (irrigation plus rainfall) amounting to Rls/m3 1203. This amount of water use, which is 64.4 % lower than its amount under maximum yield condition, resulted in 181 % increase of cultivated area. Graphic expansion path on the isolines of yield showed more dependence of wheat production on water than nitrogen. Therefore, the optimum amounts of nitrogen in the three mentioned conditions are close to each other due to its subsidized price and lower effect on wheat production relative to water.

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Regarding the public concerns about serious health risks from pesticide, the occurrences of 105 pesticide residues including Organochlorine, Organophosphorus, Organonitrogen, Dicarboximides, Strobilurin, Triazine, Pyrethroids were assessed using a descriptive method in 25 fresh and greenhouse vegetable samples (fresh carrot, greenhouse tomato and cucumber). Ethyl acetate was used for extraction of pesticides from samples and the extract was cleaned up by Envicarb Solid Phase Extraction column chromatography. Pesticide residues were identified and quantified using gas chromatography ion trap mass spectrometry detector. The mean recoveries and limit of detection of the pesticides in samples were respectively 61.67-117% and the reproducibility of relative standard deviation values for the pesticides was 3.49-14.55%. Our data demonstrated that 80% of the total analyzed samples contained detectable residues including trifluralin, permethrin, chlorpyrifos, fenvalerate, fenpropathrin and iprodione, which were below the accepted maximum residue limits (MRL_S) adopted by FAO/WHO Codex Commision Alimentarius.

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Safflower (Carthamus tinctoius L.) is an Iranian native crop that is adapted to different environmental conditions of this country. Sixteen safflower varieties/lines were spring-planted in 6 research stations including Sararood (Kermanshah), Maragheh, Ghamlo (Kordestan), Khodabandeh (Zanjan), Shirvan (North Khorasan)and Khohdasht (Lorestan) with and without drought stress conditions each in a RCBD with 3 replications. Some drought resistante indices including Mean of Productivity (MP), Geometric Mean of Productivity (GMP), Tolerance (TOL), Stress Tolerance Index (STI), Stress Susceptibility Index (SSI) for seed yield and genotypes Cell Membrane Stability (CMS) were calculated. Results showed that STI was the most appropriate index to identify drough resistant genotypes. Estimation of STI from mean of all stations revealed that Gila, CW-4440 and PI-537598 with high STI showed high seed yield in both stress and non-stress conditions. Caculation of STI standard deviation for these genotypes showed that Gila had less STI stability over the locations than other two genotypes so, CW-4440 and PI-537598 are more stable in drought stress resistance. Analysis of variance for cell membrane stability (CMS) of genotypes showed the significant differences in 1% level of probability between genotypes. S-541 had the highest and Kino-76 had the lowest CMS. There were significant and strong correlations between STI, MP and GMP with CMS namely, genotypes with more stable membrane having more drought resistance in field condition. So, cell membrance stability can be a useful and fast method to screen germplasm and identify drought resistant genotypes. Cluster analysis based on STI,MP,GMP, CMS and seed yield in both stress and non-stress conditions divided genotypes into 3 groupes. Results of clustering also identified S-541, Gila, CW-4440 and PI-537598 as 4 superior genotypes and confirmed the results of other methods.

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Achillea wilhelmsii Koch. is an aromatic plants belonging to Asteraceae family that has relatively wide distribution in different parts of Iran. In this study, we compared essential oil contents and constituents in two wild populations under two different ecological conditions (Fars and Khorasan Provinces, South West and North East of Iran respectively). The blooming herbs were collected and the essential oils of the samples were extracted after drying by “Clevenger apparatus”. Essential oil constituents were determined by GC and GC-MS. Our results showed that “Khorasan” population of Achillea wilhelmsii contains more essential oils than “Fars” population (0.65 and 0.2 % v/w respectively). Thirty components of “Khorasan” population that were 96.94% of total components were determined successfully and the main components were camphore(19.06%), cembrene(10%), 1,8-cieole(8.78%), alpha pinene(8.06%) and linalool (7.47%). Thirty-two components (91.98%) of “Fars” wild population were determined and the main components were isopentyl-isovalerate(9.46%), alpha pinene(8.75%), 1,8-cineole(8.70%), eudesmol(10-epi-gama)(5.56%), spathulenol(4.94%). Cembrene(10%), Germacrene B( 5.68 %) and Sabinene(4.34%) were detected in Mashhad population but not in Shiraz population. 10-epi Gamma Eudesmole(5.65%), Benzaldehyde dimethyl acetal(4.47%) and Ionone (4.29%) were detected in Shiraz population but not in Mashhad population. In conclusion, there are differences between these two populations as far as essential oils content and constituents are concerned.