جستجوی مقالات مرتبط با کلیدواژه « لوبیا » در نشریات گروه « آب و خاک »

Optimal physical conditions are important for proper germination and improve growth and more crop yeild. In order to investigate the effect of conservation tillage methods on soil moisture retention capacity and yield of white dry bean (Dorsa variety), in rotation with barley, an experiment was carried out at the Markazi Agricultural and Natural Resources Research and education Center during 2017-2018, 2018-2019 and 2019-2020. The experiment was carried out in randomized block design with 3 replications. Treatments were included: 1- the conventional tillage method (the use of moldboard plow – Disc), 2-Reduced tillage with chisel-packer, 3-No-tillage. The percentage of crop residues in the conventional tillage, reduced tillage and no tillage methods were 20, 50 and 90%, respectively. The results showed that the highest and the lowest yield was obtained in the reduced and no-tillage with 2869 and 2076 Kg/ha, respectively. The highest soil moisture conservation was observed in the no-tillage and reduced tillage. So that the amount of soil moisture moisture in the reduced tillage and no tillage on the fourth day after irrigation, were 1 and 1.8 percent higher than the conventional method, respectively. The results showed that the use of the reduced tillage method compared to the conventional method in drip irrigation method without reducing crop yield leads to more soil moisture retention and thus helps to improve water efficiency in bean production. In general, based on the results, due to the low soil organic matter in the region, using reduced tillage method is a suitable option to conserve soil and water resources and increase water productivity in the bean production.

Current study was carried out by the aim of investigating the effect of rhizobium bacteria and arbuscular mycorrhizafungi on yield and micronutrients concentration on bean under different irrigation regimes in 2016 and 2017 years.In a split plots design, thethree regimes irrigation, S1= 95-100% available water(AW), S2= 75-80% AW and S3= 55-60 % AW were assigned to main plots and six bio-fertilizers, including T1= Rhizobium leguminosarum bv.  Strain of 177 and T2= Rhizobium leguminosarum bv.strain of 160 used for seed inoculation, T3= Arboscular mycorrizal (Funneliformis mosseaeand Rhizophagus irregularis) used for soil inoculation, T4= T1+T2, T5= T1+T2+T3 and T6= control were randomized to subplots. There were significant differences (p˂0.05) in yield and micronutrients concentration under irrigation regimes and bio fertilizers treatments. Highest grain yield (2371 kgha-1) was obtained in irrigation on 75-80 % available water and 160 Rhizobium inoculated treatment. The highest concentration of Fe, Mn, Zn and Cu in seed plant were in irrigation on 75-80% available water and co-inoculated treatment. The addition of Fe, Mn, Zn and Cu concentrations were, 21.4 %, 5.7%, 3.5% and 3.3% respectively than control treatment. These results suggest that inoculation of seed bean by Rhizobium and mycorrhiza, can improve yield and resistance to drought stress by increasing of micronutrients concentration in seed bean plant.

Soil tests play a very important role in management of nutrients in the field. The efficiency of a soil test result depends on extractant suitability for determination of available nutrient. Also, for calibration of each nutrient in the soils of a specific region and plant, a critical limit should be determined so that the soil test for each element can be the basis of fertilizer recommendation. Bean (Phaseolus vulgaris L.) is important agricultural product due to high protein. Due to the lack of relevant information in this field, this study was conducted on bean soils in Markazi province. 30 samples of surface soil (0-30cm) with a wide range in terms of available potassium, as well as physical and chemical properties were selected from the bean cultivation soils of the Markazi province and after preparing soil samples in the greenhouse, beans were planted in them.In order to evaluate the response of bean to potassium fertilizer application, two levels of 0 and 100 mgKkg-1 were used as potassium sulfate in this experiment. The greenhouse experiment was performed in a completely randomized design with three replications. At the end of the growing season, harvested plants and plant responses including dry matter weight,  potassium concentration and uptake, and relative growth were determined. Six extractants including distilled water, hydrochloric acid 0.13M, nitric acid 0.5M, calcium chloride 0.025M, Olsen and ammonium acetate 1M were evaluated to extraction of available potassium. The results of analysis of variance showed that the main effects of soil and potassium fertilizer were significant (p<0.01) on dry matter weight, potassium concentration and uptake. But the effect of soil and fertilizer interaction was significant only on plant potassium concentration.Comparison of the mean showed that the effect of potassium fertilizer application were significant on plant responses.The results of correlation coefficient of different extractants with plant responses showed that ammonium acetate (1M) had a positive and significant correlation with plant potassium concentration (0.67**) and uptake (0.63**) while other extractants did not show a significant correlation.Using the Cate and Nelson visual method, the potassium critical level was obtained 150 mgkg-1 soil by extracting with ammonium acetate. Dry matter weight had a positive and significant correlation with available potassium concentration, cation exchange capacity, clay and sand. Plant potassium concentration and uptake had a positive and significant correlation with available potassium concentration (r=0.555**) and soil organic carbon (r = 0.620*).

Iron (Fe) is an important micronutrient that plays a role in several crop physiological processes such as photosynthesis, respiration, and synthesis of heme proteins, DNA, RNA, and hormones. The most common Fe source used in agriculture is Fe-EDDHA. However, the usage of this chelate may be problematic for plant growth. In the recent years, organic chelates have gained attention as they increase the microelements solubility and prevent iron precipitation in nutrient solution. Organic chelates such as amino acids and polysaccharides have many physicochemical (reactive OH, COOH and NH2 groups) and biological (biocompatible and biodegradable) properties that make these attractive materials usable for the agricultural practice. Biodegradability, low toxicity, immune system stimulation, the ability to coordinate metal, less sensitivity to photodegradation, and the effect on physical properties of rhizosphere and root growth dynamic are ideal properties of these components. The objective of this study was to evaluate Fe-organic-chelates efficiency as Fe sources for bean (Strategy I) and corn (Strategy II) growth in the hydroponic system.

In this research, we synthesized Fe-amino acid chelates including  Fe-Glycine (Fe-Gly), Fe-Phenylalanine (Fe-Phe), Fe-Tyrosine (Fe-Tyr), Fe-Methionine (Fe-Met), and Fe chitosan chelates in two forms of acidic hydrolyzed chitosan [Fe-C(A.hyd)] and enzymatic hydrolyzed chitosan [Fe-C(E.hyd)] and characterized by FTIR and CHN analyzer. The efficiency of these iron sources for bean (Strategy II) and corn (Strategy I) in hydroponic system was then evaluated. Seeds of bean and corn were washed with distilled water and transplanted into special containers containing coco peat, perlite and vermicompost (1:1:1) at 25 °C for germination and initial growth. The seedlings were transferred to polyethylene plastic lids fitting tightly over 8-L polyethylene containers under controlled conditions in the greenhouse with a light period of 8 hours per day, the temperature of 20 to 25°C and relative humidity of 65 to 75%. The pots were stacked in black color to prevent light reaching the root of the plant and the solution. In each pot, one plant seedling was placed and the basic nutrient solution was prepared in deionized water. The plants were harvested after 8 weeks, their root and shoot were separated and dried after washing with distilled water in an oven at 75 ° C. The dried samples were ground to fine powder to pass through a 20-mesh sieve. The analysis of Fe in samples was performed using atomic absorption spectrophotometer.

Application of organic chelates of amino acids and chitosan increased the shoot dry matter per plant compared to Fe-EDDHA. Fe content in shoot of corn and bean was highest using Fe-Tyr, Fe-Met and [Fe-C(A.hyd)]. Uptake and accumulation of Fe in roots were observed by using all chelates, but the highest translocation factor was found for the treatments including [Fe-C(A.hyd)] and Fe-Tyr. Translocation factor in bean plants was higher than corn, and around half of Fe in bean plants was translocated from root to shoot. The use of iron chelates in plant growth medium increased the activity of ferric chelates reductase enzymes in bean and corn compared to Fe-EDDHA. However, the mean of this enzyme activity in bean was higher than that in corn. Therefore, the activity of this enzyme can be used as an indicator for determining the iron availability in leaf cells in Strategy I and Strategy II plants. In general, the plants need less energy to absorb Fe when the chelates with a simpler structure are used.

The results indicated that using Fe organic chelates in the hydroponic system could supply sufficient amounts of iron for the plant uptake and also improve the root and the shoot growth of bean and corn. Overall, the effect of Fe organic chelates on Fe content of bean and corn shoots was in the following order: Fe- Chi(A.hyd) > Fe-Tyr > Fe-Met > Fe-Gly >. Activity of leaf ferric chelate reductase in bean was higher than that in corn.

In order to study the effects of rhizobium bacteria and arbuscular mycorrhizal fungi on water use efficiency and the grain yield of bean, under drought stress conditions, two-year year field experiments were conducted during 2015 and 2016 growing seasons. The experimental design was a split plot arranged in an RCBD with 4 replications. Three irrigations including S1= 95-100% AW (Normal irrigation), S2= 75-80% AW(Moderate drought stress) and S3= 55-60% AW (severe drought stress) were assigned to the main plots and six bio fertilizer treatments including T1=177 rhizobium bacteria strain, T2=160 rhizobium bacteria strain used for seed inoculation, T3= mycorrhizal arboscular fungi used for soil inoculation, T4= T1+T2, T5= T1+T2+T3 and T6= control (no seed and soil inoculation) were randomized to the subplots. Based on the combined analysis of variances for two years, there were significant differences (p˂0.05) in the grain yield, yield components and water use efficiency between the irrigation stress and bio fertilizer treatments. The highest grain yield (2371 kg ha-1) and water use efficiency (522 g m-3) were obtained in the S2T2 treatment. In this treatment, 160 and 177 rhizobium bacteria (T2) in moderate drought stress (S2) were used. These results suggested that inoculation with the rhizobium of seed bean in arid and semi-arid areas could improve yield, water use efficiency and resistance to drought stress by increasing the growth in the root and shoot of the plant.

Optimal management of water, as one of the main factors of production has an important role in the supply of essential nutrients, increasing yield and reducing leaching. Nowadays, application of magnetic water in many fields including agriculture has been payed attention by many researchers. In order to investigate the effect of magnetic water on plant nutrient uptake, this research was conducted in the controlled environmental conditions in greenhouse of Tarbiat Modares University. Magnetic water was produced using a magnetic device with a magnetic field intensity of 8 to 10 mT. The objective of this study was to investigate the effect of magnetic water on the essential nutrient uptake by bean (Phaseolus vulgaris) in saline conditions. The experimental design was two factors factorial (2x3) arranged in a completely randomized design. The combinations of the treatments were two levels of water; non-magnetic (Normal) and magnetic and three levels of salinity; 800, 1300 and 2100 ppm NaCl, with three replicates. The results showed that with increasing salinity, macronutrient uptake and protein percentage reduced, while micronutrient and sodium uptake increased. Moreover, comparisons of treatments means showed that the magnetic water increased all the nutrients uptake and protein percentage in the leaves and seeds, but no significant changes were observed in the roots and shoots of bean plants. Despite these findings, more researches are needed to be done in the field to prove the obvious beneficial effects of magnetic water.

The drought stress is the most important of abiotic stress for plants. In dryand regions, the implication of drought tolerant strains of rhizobia is a critical way to enhance yield and development of nitrogen fixation in beans farming.To investigate the effects of rhizobial strains on yield of common bean under drought stress, this study was performed based on randomized complete block design as a split plot experiment with 12 treatments in 3 replications during 2014 and 2015. The treatments were irrigated to achieve the values of 30, 60 and 80 % available soil moisture as drought stresses (sever-, moderate- and non-) in main plots and inoculated seeds by rhizobium bacteria strains 54, 58, 160 and 177 arranged in sub-plots. The volume of irrigation water, water use efficiency, plant nitrogen, yield and yield components were determined. The results in 2 years revealed that, the drought stress and rhizobium treatments showed significant (P-1) was obtained in irrigation level at 60 % available water (moderate stress) and seed inoculated by rhizobium bacteria strain 160. These results showed that, the application of rhizobium bacteria strain 160 increased drought tolerance without any reduction of yield in common bean.

Determination of plants evapotranspiration is one of the most important factors in promoting the utilization of water resources in agriculture. This factor is indicative of the potential depletion rate from wet soil surface and vegetation; hence, it is important to be studied. This research has been done to measure and estimate potential evapotranspiration, and single crop coefficients based on intercropping of forage maize single cross 704 (Zea mays L.) cultivar and bean effort (Vicia faba L.) cultivar, using the drainage Lysimeter, located in the research farm of the University of Tabriz. The potential evapotranspiration of intercropping was obtained, 967.37 mm during the growing season. . In this research reference evapotranspiration was determined, 955.77 mm using FAOPenman- Monteith equation for the studied area. Length of intercropping growth periods in initial, development and final stages, were determined equal to 18, 37, 41 and 17 days, respectively. Alsothe amount of growing degree days at the same stages were 179, 567and 227, respectively. Single crop coefficient was obtained, for initial, middle and final growth stages equal to 0.67, 1.17 and 1.09 respectively. Due to lack of crop coefficients for the case of intercropping, using the obtained coefficients are recommended for this type of crop irrigation scheduling.

This research investigate the potential of Rhizobium leguminosarum b.v. phaseoli to improve growth and nutritional status of common bean (Akhtar cultivar) at three levels of salinity of S0, S1 and S2 (0, 35 and 70 mM sodium chloride, or 0, 3 and 6 ds/m, respectively). The greenhouse experiment was conducted as a factorial design in randomized completely with three replications by using the sterile sand-perlite (2:1 v/v) as a culture substrate. The results showed that salinity decreased plant growth, regardless of microbial treatment and stress level. The inoculated plants with rhizobium had greater shoot and root biomass than the non-inoculated plants at all salinity levels. Salinity stress decreased enzyme activity catalase and potassium and nitrogen concentrations of shoot and increased enzyme activity peroxidase sodium concentration of shoot, particularly in non-inoculated plants with rhizobium. At salinity levels of S1 and S2, enzyme activity catalase of inoculated plants with rhizobium about 196% and 259% and enzyme activity peroxidase about 93%, 73% and 7% was increased than the non-inoculated plants, respectively. Inoculation of rhizobium at salinity levels of S1 and S2, resulted in increasing of potassium concentration about 84% and 10% and decreasing of sodium concentration about 50% and 70%, respectively. Also, the inoculated plants with rhizobium had higher nitrogen concentrations at S0 and S2 in compare to the non-inoculated. Shoot phosphorous concentration of inoculated plants with rhizobium was higher about 55% than the non-inoculated plants.

In order to study the effect of intercropping of corn with bean and bitter vetch and farmyard manure (FYM) on corn nutrition, a factorial experiment was carried out on the basis of randomized complete blocks design with three replications. The factors were types of intercropping systems at levels of sole bean, bean+corn, sole bitter vetch, bitter vetch+corn, sole corn, and FYM at levels of 0, 30 and 60 tons per hectare. The results showed that intercropping of corn with bean and bitter vetch increased significantly concentrations of N, P, Fe, Zn, Cu and Mn of corn shoot compared to the sole corn, while it had not significant effect on concentrations of Ca, Mg and Na of corn shoot. The interactive effects of cultivation type and FYM on concentrations of N, Ca, Mg, Na, Fe, Zn and Cu of corn shoot were not significant but the effects of cultivation type on concentrations of P, K and Mn of corn shoot were dependent on the level of FYM application. Application of 30 and 60 tons FYM per hectare increased significantly concentrations of N, P, K, Ca, Mg, Na, Fe, Zn, Cu and Mn of corn shoot compared to the control. In general, the intercropping of corn with bean and application of FYM at the rate of 60 tons per hectare can be recommended for improving corn nutrition and its forage quality in the study area and similar conditions.

The ability of different soil tests in predicting soil phosphorus (P) is important in soils amended with municipal sewage sludge. The objective of the present study was to evaluate several chemical extractants to estimate available P for bean growing in 10 calcareous soils amended with municipal sewage sludge from Chaharmahal-Va-Bakhtiari province under the greenhouse conditions. For this purpose, the soil samples were incubated with sludge at a rate of 39-ton sludge ha–1. The amount of available P of the soil samples was determined by Olsen, Colwell, ammonium bicarbonate-DTPA, 0.01 M calcium chloride, BrayІ, ІІ, Mehlich І and ІІ methods. A pot experiment in a completely randomized design was conducted to evaluate the bean plant indices. The results showed that the amount of extractable P with the above methods decreased in the following order: Colwell> Bray ІІ> Mehlich ІІ> Olsen> Ammonium bicarbonate DTPA> Mehlich І> Bray І> 0.01M chloride calcium. The extractable P with 0.01M chloride calcium, Mehlich І, ІІ Colwell and Olsen methods correlated significantly with plant indices (P concentration and P uptake). Thus, mentioned methods could be used to estimate plant-available P in the soils amended with sewage sludge.

Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling is one of the most important factors in crop’s quality and quantity. The main objective of irrigation scheduling is to control crop’s water conditions in order to achieve its optimum yield level. So irrigation timing is the vital factor on which crop water stress and eventually yield's level are dependent upon. Moreover, irrigation timing is used in irrigation scheduling. The aim of this study was to evaluate the effect of irrigation time on water consumption, water use efficiency and yield of beans. In order to observe the effect of the amount and the time of the irrigation on water consumption, yields rate and water use efficiency, the current research was carried out at the University of Shahrekord during the summer of 2012. The experiment was done as a completely randomized design with 4 repetitions consisting of irrigation time and the amount of irrigation in 4 and 2 levels (at, 8, 14 and 18) and (deficit irrigation, full irrigation), respectively. Beans seeds were planted in 32 similar vases with a diameter of 45 cm and height of 60 cm, in each experiment. Treatments were begun after 37 days from planting. Treatments were irrigated when the average moisture in the root zone was equal to the lower border of readily available water of full irrigation. At the end of the experiments, plants were completely harvested. Then the plant’s height, number of branches, numbers of pods per plant, pod and seed weight were measured. Results showed that irrigating at different times during the day influenced water use efficiency, water consumption, seeds yield and number of pods in the bush. The water consumption was affected by irrigation time. Among full irrigation treatments, irrigation at 2 p.m. and 6 a.m. had the highest and lowest water consumption, respectively. The total amount of water used in irrigation at 8 a.m., 2:00 p.m. and 6 p.m. compared to 6:00 a.m. was increased by1.6, 9.5 and 4.1 percent, respectively. The results showed that irrigation at 2:00 p.m., caused a significant reduction in yield. Moreover, water use efficiency in 6 a.m. treatments had increased 18.5 percent more than that of the 2:00 p.m. irrigation treatment. The time of irrigation did not have a meaningful effect on bush height, the number of minor branches, the pod's length. The effect of the amount of irrigation water was meaningful on bush height, number of minor branches, seeds yield, the number of pods in the bush, pods length and seed weight. Seed yield at 8:00 a.m., 2:00 p.m. and 6:00 p.m. treatments has shown 0.29, 17.1 and 7.6 percent decrease in comparison with 6:00 a.m. irrigation treatment, respectively. Moreover, 100-seed weights were significantly affected by the irrigation time. The maximum and minimum weights of 100- seed weights were obtained at 6:00 a.m. and 6:00 p.m. irrigation, respectively. Analysis of variance showed that the number of pods per plant was affected by irrigation time. The maximum number of pods per plant was 101 which belong to the 6:00 a.m. treatment. In this experiment in the case of irrigation at 2:00 p.m., the number of pods per plant was significantly decreased in full and deficit irrigation. The results showed that although the irrigation frequency was the same, irrigation at maximum evapo-transpiration caused the plant to be under stress and the yield was reduced. In other word, it can be said that time of irrigation had no meaningful effect on the appearance and shape of the plant while it was effective in terms of the yield. Overall assessments showed that maximum of the measured features were obtained in the case of 6:00 a.m. treatment. The results showed that irrigation at different times of the day and the applied water stress, reduced water use efficiency. These caused traits such as plant height; number of branches; number of pods per plant; pod and seed weight to be affected by the irrigation depth. Based on the results of this experiment it can be stated that, when there is no limit of water supply, it is recommended to irrigate in the early morning, before the steep slope of the temperature rise. However, in the situations with water shortage problems, is better to manage the water and the product.

Change in microorganism activity and chemical properties can be affect on availability and fractionation of Copper (Cu). This research was conducted to investigate the availability and fractionation of Cu in the bean rhizosphere and bulk soils in 10 calcareous soils using rhizobox at greenhouse. Total organic carbon (TOC)، dissolved organic carbon (DOC)، microbial biomass carbon (MBC)، pH، available Cu (by using 7 chemical extractants) and Cu-fractions were determined in the rhizosphere and bulk soils. The results indicated that in the bean rhizosphere soils، TOC، DOC and MBC increased significantly (p)

Sewage sludge uses as a low coast fertilizer to rectify deficit of elements such as zinc (Zn). A suitable extractant for estimation of bean-available Zn in calcareous soils amended with sewage sludge has not yet been introduced. The aim of this research was to assess several chemical extractants for the estimate of available Zn in sewage sludge-amended calcareous soils. For amended soils, 1% (w/w) of sewage sludge was added to 10 calcareous soils, and the soils (amended and un-amended) were incubated at field capacity for 30 days. At the end of incubation, soils were air-dried and available Zn was determined using 7 chemical extractants (DTPA-TEA, AB-DTPA, Mehlich 1, Mehlich 2, Mehlich 3, 0.1 N HCl and 0.01 M CaCl2). Zinc concentration in shoots, Zn uptake, and shoot dry weight of bean were determined in a pot experiment in amended and un-amended soils. The results show that Mehlich 3 and Mehlich 1 extractants extracted the highest and the lowest concentrations of Zn in both amended and un-amended soils, respectively. Furthermore, all three studied indices and Zn extracted by using different methods increased in amended soils. In addition, results indicated that significant correlations were found between extracted Zn using AB-DTPA, DTPA-TEA and Mehlich 3 and plant indices in un-amended soils. On the contrary, in sewage sludge-amended soils only the correlation between extracted Zn using DTPA-TEA and Mehlich 1 with Zn uptake and shoot dry weight and Mehlich 2 with Zn concentration was significant. The results of this study showed that DTPA-TEA could estimate bean-available Zn in the sewage sludge-amended and –un-amended calcareous soils.

The objective of the present study was to evaluate several chemical extractants to estimate available phosphorus (P) for bean growing in calcareous soils from Chaharmahal-Va-Bakhtiari province. The amount of available P was measured by Olsen، Colwell، ammonium bicarbonate-DTPA، 0. 01 M calcium chloride، BrayІ، ІІ، Mehlich І and ІІ extractants. In addition، soil organic P and total P were determined. A pot experiment consisting of a completely randomized design with three replications was conducted to evaluate the plant performance in association with chemical extractants. After the harvest، dry weight، P concentration and P uptake were determined. The results showed that the amount of extractable P decreased in the following order: Colwell> Mehlich ІІ> Bray ІІ> Olsen> Ammonium bicarbonate -DTPA> Mehlich І> Bray І> 0. 01M Chloride calcium. Organic and total P and phosphorus extracted by Colwell، Olsen and Mehlich ІІ methods correlated significantly with plant indices. In addition، the results of stepwise regression analysis showed that the organic P، Colwell and Olsen extractants could explain more variation in the indices of bean plant. The results of this research showed that Colwell، Olsen and MehlichІІ extractants could be used to estimate plant-available P in the studied calcareous soils.

This study was conducted to evaluate N2-fixing ability of rhizobia strains inoculated with common bean. The experiment was carried out in a randomized complete block design (RCBD) with 13 treatments including 10 Rhizobium isolates، two nitrogen fertilizer levels (200 and 400 kg urea per ha) and one control (without Nitrogen and rhizobium) in four replications at Esmaeel Abad research station of Qazvin. Plant sampling was done in two growth stages and nodule number and dry weight، shoot dry weight and total N-uptake and seed yield were evaluated. Results of two years field experiment showed that isolate L-75 showed the superior N2-fixing performance and had the highest positive effect on growth factors and could be recommended to use as inoculants strain in Qazvin region. This isolate، produced highest nodule number and dry weight in both years of study. Seed yield production was promoted by 26 and 40% more than control by application of isolate L-75 in the first and second year، respectively. This study showed that inoculation of common bean with effective rhizobia strains resulted in promoting of plant growth and seed yield production and have the benefit to reduce nitrogen fertilizer application in bean cropping.

Petroleum pollution is one of the most common and dangerous pollutions that is due to petroleum industries such as refineries, and consequently of oil pipes and tanks leak causing environmental pollutions. One of the newest born technologies in this area is phytoremediation, in which plants are used for decreasing of petroleum pollution. This technology is used for remediation of soil, underground and waste water pollution, because of low expenses and simple application. In this research bioremediation system by three plants barley, vetch and bean at three levels of density, with three replications in factorial experiments, randomized complete block design (RCBD) was used. In three steps of plant growth, concentration of total petroleum hydrocarbons (TPHs) of soil was measured. Statistical analysis showed that the amount of soil remediation had a direct relation with increasing plant density levels. The maximum remediation belonged to barley which in it's maximum density level, it reduced the amount of pollution up to 45.78%. Generally, because of high resistance of barley to petroleum pollution and it’s ability for remediation of pollution, barley was recognized as the best plant among the evaluated treatments for remediation of petroleum polluted soils.

Crop residues are beneficial substances that can bring about important changes in soil biological, chemical and physical properties and can also increase or stabilize crops yield. A field experiment was carried out at Research Station of College of Agriculture, Shiraz University, Shiraz, Iran, to determine the effects of wheat (Triticum aestivum L.) residue rates in combination with N levels on some soil properties in common bean (Phaseolus vulgaris L.) cultivation for two years (2008-2009). The experiment was conducted as split split-plot arranged in a completely randomized blocks design with three replications. Treatments were two red bean cultivars as main plots, N levels (0, 34.5, 69, and 103.5 kg ha-1) as sub-plots and residue rates (0, 25, 50 and 75%) as sub sub-plots. The results showed that application of crop residues significantly increased soil organic carbon, N, K, and P contents. Heavy crop residue (75%) application had no effects on these soil properties. Thus, retaining 50% crop residue was optimum for proper soil quality. Increased N application increased soil N, decreased P and K contents, and had no effects on organic carbon.

This research was conducted in order to determine the relationship between grain yield and yield components, using 30 common bean varieties in a randomized complete block design with four replications at the Agricultural filed faculty of Agriculture,Tehran university In this study 18 traits were assessed on 10 random plants from each plot. The result showed that there were significant differences among varieties in terms of trait under study, indicating the existence of genetic variation among varieties. Also results showed that the grain yield had a positive and significant genotypic correlation with number of seed/pod, pod weight, number of pod/plant, biological yield, days to flowering and maturity. Stepwise regression analysis showed that the maximum variation in grain yield could be attributed to the number pod/plant, number seed/plant, 100 seed weight and pod length. The results of path analysis showed that the highest direct effect, being positive, was related to number seed/plant and the lowest direct effect, which was related to number pod/plant. Factor analysis resulted in three factors that accounted for 78/7% of total variation. The first factor accounted for 38.39% of total variation and was designated as yield and yield component factor. This factor is comprised of pod weight, biological yield, grain yield and number of pod/plant traits.