oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 513 )

2018 ( 704 )

2017 ( 696 )

2016 ( 966 )

Custom range...

Search Results: 1 - 10 of 401174 matches for " M. Afyuni "
All listed articles are free for downloading (OA Articles)
Page 1 /401174
Display every page Item
Effect of Organic Matter on Soil Chemical Properties and Corn Yield and Elemental Uptake
Y. Rezaenejad,M. Afyuni
Journal of Science and Technology of Agriculture and Natural Resources , 2001,
Abstract: Due to high production of organic residues such as sewage sludge and compost, land application is probably the best way to prevent accumulated residues in the environment. However, the risk involved in the land application of organic residues should be evaluated prior to the assessment of their economic and fertilizer values. The objective of this study was to evaluate the effect of organic residues on soil chemical properties, yield and uptake of heavy metals and nutrients by corn (Zea mays L.). The study was a randomized complete block design with three replications with four treatments including cow manure, sewage sludge, municipal compost and inorganic fertilizer. The organic amendments were applied to the plots at a rate of 50 t ha-1 and inorganic fertilizer treatment consisted of 250 kg ha-1 ammonium phosphate and 250 kg ha-1 urea. Organic amendments significantly increased soil organic matter content, EDTA-extractable Fe, Zn, Cu and Pb and plant available P, K, and N. Uptake and concentration of nutrient in corn grain and shoots were significantly affected by treatments, whereas Cd and Pb concentrations were the same among the treatments. Cow manure and sewage sludge treatments had the highest and compost had the lowest corn silage and grain yields. Overall, the results indicated that cow manure and sewage sludge had a high fertilizer value and led to heavy metal concentrations in soil as well as corn tissues which were much lower than the reported standards.
Estimation of Field Capacity and Permanent Wilting Point from Some Soil Physical and Chemical Properties
F. Noorbakhsh,M. Afyuni
Journal of Science and Technology of Agriculture and Natural Resources , 2000,
Abstract: Field capacity (FC) and permanent wilting point (PWP) are important factors affecting irrigation scheduling and field management. FC and PWP can be estimated from some of the soil physical and chemical properties. Pressure Plate apparatus is usually used for determination of FC and PWP, but this is a time-consuming and laborious procedure; besides, the apparatus may not be available in many laboratories. Samples were taken from 23 locations in Isfahan and Chaharmahal Va Bakhtiary provinces in central Iran. Soil texture, organic matter and cation exchange capacity were determined. Soil moisture at FC and PWP of the soils were measured with a pressure plate. Simple and multiple regression analyses were used to study the relationships between FC and PWP with sand, silt, clay, soil organic matter and cation exchange capacity. Results indicated that FC significantly correlated with sand, organic matter and cation exchange capacity in a stepwise model (r=0.97**). The PWP of soil also correlated significantly with silt, organic matter, and cation exchange capacity in a stepwise model (r=0.95**). Available water capacity (FC-PWP) correlated with sand in a stepwise model (r=0.82**). On the whole, results showed that FC and PWP can be estimated from some soil physical and chemical properties.
Modeling Cadmium and Lead Balances in Agricultural Lands of Isfahan Region, Central Iran
M. Amini,M. Afyuni,H. Khademi
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: Heavy metals including cadmium (Cd) and lead (Pb) are entering agricultural soils from different routes and mainly due to human activities. Accumulated Cd and Pb in the soil would eventually enter the human and animal food chains and pose threat to their health. Therefore, evaluating heavy metal accumulation is necessary to prevent soil and environmental pollutions and should be considered by researchers as well as policy makers. This study was conducted to model the accumulation rates of Cd and Pb in the agro-ecosystems of Isfahan, Mobarakeh, Lenjan, Borkhar, Najafabad, Khomeinishahr and Felavarjan. Cadmium and lead accumulation rates in the agro-ecosystems were computed using a stochastic mass balance model which uses Latin Hypercube sampling in combination with Monte-Carlo simulation procedure. Agricultural information including crop types, crop area and yield, the type and the number of livestock, application rate of mineral fertilizers, compost and sewage sludge and also metal concentration in plant and amendments were used to quantify Cd and Pb accumulation rates. Modeling Cd and Pb accumulation rates indicated that the metals are accumulating in the agricultural lands in the studied townships. The largest Cd (18 g ha-1 yr-1) and Pb (260 g ha-1 yr-1) accumulation rates were found in the township of Isfahan but the minimum accumulation rates were found in township of Lenjan for Cd (3 g ha-1 yr-1) and Mobarakeh for Pb (10 g ha-1 yr-1). The major input route to agricultural soils is phosphate fertilizers for Cd but for Pb is manure on the regional scale. High application rates of sewage sludge and compost in agricultural lands in the township of Isfahan could result in considerable amounts of Cd and Pb entering the soils of this region.
Effect of Manure on Hydraulic Characteristics and Bromide Movement in a Sandy Loam Soil of Kerman
H. Naghavi,M. A. Hajabbasi,M. Afyuni
Journal of Science and Technology of Agriculture and Natural Resources , 2005,
Abstract: The objective of this study was to evaluate effects of cow manure on soil hydraulic properties and bromide leaching in a sandy loam soil (coarse loamy mixed, Typic Torrifluvents). Manure was applied at 0, 30, and 60 tha-1 at three replications in a completely random design. Three months after manure application potassium bromide (KBr) at rate of 300 Kg ha-1 Br was uniformly applied on the surface. Soil bulk density, porosity, organic matter, and soil moisture at18 levels of matric potentials were determined. Soil samples to the depth of 105 cm at 15-cm increments were collected after 100, 200 and 400 mm of irrigation. Soil bulk density, porosity, organic matter content, and soil moisture at different levels of matric potential increased significantly with manure application. Manure application also significantly affected the hydraulic parameters. Bromide leaching was significantly lower in plots with manure application and the greatest leaching occurred at the zero manure application treatment. The center of mass evaluation indicated a relatively similar result with measured values.
Effect of Sewage Sludge on Mercury Concentration in Soil and Corn
M Karimpour,M Afyuni,A Esmaili Sari
Journal of Science and Technology of Agriculture and Natural Resources , 2010,
Abstract: Sewage sludge application on farmland as fertilizer is commonly practiced in many countries. However, high concentration of heavy metals like mercury (Hg) in sludge can cause pollution of soil, plant and the human food chain. In order to examine the risk of Hg transfer into plants a five year field experiment was conducted in which we investigated uptake of Hg from a sludge-amended soil by corn. Sludge application rates were 0, 25, 50 and 100 Mg ha-1. To study cumulative and residual effects of the sewage sludge, applications were repeated on 4/5 of each plot in second year, on 3/5 of plots in third year, on 2/5 of plots in fourth year and in 1/5 of plots in fifth year. After the fifth year, soil samples from the 0-20 and 20-40 cm depths were taken and analyzed for total Hg. Corn plants were harvested and roots, stems and grains were separately analyzed for Hg concentrations. Sludge application significantly increased total Hg concentration in soil. Total Hg concentration in soil ranged from 20 μg kg-1 (in control plots) to 1200 μg kg-1 (in plots with 500 Mg ha-1 sludge application). Sludge application significantly increased uptake of Hg in different plant parts. At the end of the fifth year the average Hg concentrations in root, stem, and grain were 91, 9, and 8 μg kg-1, respectively. Corn yield increased significantly with sludge application and this fertilizer effect was visible five years after a single sludge application.
Effects of Sewage Sludge, Compost and Cow Manure on Availability of Soil Fe and Zn and their Uptake by Corn, Alfalfa and Tagetes Flower
M. Sharifi,M. Afyuni,A. H. Khoshgoftarmanesh
Journal of Science and Technology of Agriculture and Natural Resources , 2011,
Abstract: Micronutrients such as Fe and Zn in adequate level are essential for plant growth cycle and impose a vital role in increasing yields of most agricultural crops. Using organic wastes such as sewage sludge, compost and manure is a proper practice for returning organic matter and some nutrients into the soil, particularly in arid and semi-arid regions. The objective of this study was to determine the effects of sewage sludge, compost and cow manure on availability of Fe and Zn in soil and their uptakes by corn, alfalfa and targetes flower. A completely randomized design with three treatments (sewage sludge, compost and cow manure at 25 Mg/ha) was used. Application of sewage sludge, compost and cow manure significantly increased availabile Fe and Zn of the soil. The application of organic wastes increased the dry matter yield of the plants. Fe and Zn concentration of plants shoots in organic amendments treatments were significantly greater than blank. The highest mean concentration of Fe in plant tissues was obtained in the cow manure and the highest mean concentration of Zn in plant tissues was obtained in the compost treatment.
Effect of Sewage Sludge, Compost and Cow Manure on Growth and Yield and Fe, Zn, Mn and Ni Uptake in Tagetes Flower
M. Sharifi,M. Afyuni,A. H. Khoshgoftarmanesh
Journal of Science and Technology of Greenhouse Culture , 2010,
Abstract: A pot experiment was conducted in Isfahan University of Technology research greenhouse to investigate the effects of sewage sludge, compost and cow manure on growth and uptake of Fe, Zn, Mn and Ni in tagetes flower. A completely randomized research with three treatments (sewage sludge, compost and cow manure at 25 Mg ha-1) and three replicates was performed. Application of organic wastes significantly increased organic matter and CEC of the soil. Application of compost significantly increased DTPA-extractable Fe, Zn, Mn and Ni of the soil. The use of organic wastes increased tagetes flower growth. The growth of plant was highest in the compost treatment. Results indicated that Fe, Zn, Mn and Ni uptake by plant shoot, and the percentage of metals translocated to the shoot was greater in the compost treatment compared to other treatments. In general, the application of compost for tagetes flower had a positive impact on plant growth parameters and micronutrients uptake.
Status of Zinc and Cadmium in Paddy Soils and Rice in Isfahan, Fars and Khuzestan Provinces and their Effect on Food Security
M. Pirzadeh,M. Afyuni,A. H. Khoshgoftarmanesh
Journal of Science and Technology of Agriculture and Natural Resources , 2012,
Abstract: 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.
Impact of Tillage System on Soil Physical Properties and Bromide Leaching
M. Afyuni,M.R. Mosaddeghi
Journal of Science and Technology of Agriculture and Natural Resources , 2001,
Abstract: Tillage system effect, Conventional (CT) vs. No-Till (NT), on soil physical properties and Br transport was studied at two locations in North Carolina. The soil types were a Typic Paleudults at Coastal Plain (site 1) and a Typic Kanhapludults at Piedmont (site 2). Bulk density (BD), total porosity (TP), macroporosity (MP), and saturated hydraulic conductivity (Ks) .were measured in plant row (R), and trafficked (T) and untrafficked (N) interrows. A rainfall simulator was used to apply two early season rainfalls to 1 m2 plots where KBr suspension was surface applied for Br leaching study. The first simulated rainfall event (30 min) consisted of a low (1.27 cm h-1) or a high (5.08 cm h-1) rate applied, 24 h after Br application. One week later, the high rainfall rate was repeated on all plots. Soil samples were taken two days after applying first and second simulated rainfall (a week between them) and the end of season from different depths for measuring Br concentrations. Soil physical properties were affected by both tillage system and position. Bulk density was higher in NT versus CT and in T position versus Rand N positions. Total porosity was lower in NT versus CT but MP was significantly higher in NT. Saturated hydraulic conductivity was about 90% lower at T position versus N and R positions. Coefficient of variation was quite large, making it difficult to obtain statistical differences between tillage systems. The surface l0-cm of soil contained the highest Br concentration for depth treatments with treatment differences occurring primarily in 0 to 25 cm depth. In first and second sampling dates, more Br leached under NT versus CT system. However, there was no significant difference between the two tillage systems in Br leaching at the end of the growing Season. In site 1, Br leached more due to the coarse texture and high Ks of the soil.
Nitrogen Mineralization Potential in a Calcareous Soil Treated with Two Organic Fertilizer
Y. Lotfi,F. Nourbakhsh,M. Afyuni
Journal of Science and Technology of Agriculture and Natural Resources , 2008,
Abstract: Organic fertilization has been practiced in Iran due to the shortage of soil organic matter. In recent years, attention has been payed to the organic fertilizers because their commercial production has recently started and demands for their application have increased. The objectives of this study were to investigate the effects of organic fertilizer type, rates and times of application on the N mineralization potential (NMP) in a calcareous soil (fine loamy, mixed, thermic, Typic Haplargid) in Isfahan region. The soil samples were collected from a previousely established field experiment. The experiment design was split plot with three replications. Each main plot was split into subplots receiving 1, 2 and 3 annual consecutive applications of cow manure and sewage sludge at the rates of 0, 25 and 100 Mg ha-1. The soil samples were taken from 0-15 cm depth, 6 months after the third application of the organic fertilizers. Nitrogen mineralization potential was measured by a long-term leaching-incubation procedure. Results indicated that NMP was similarly affected by cow manure and sewage sludge. Nitrogen mineralization potential in the treatments which received 100 Mg ha-1 organic fertilizers, was 4 and 1.7 times greater than that of control and 25 Mg ha-1 treatments, respectively. A significant increase was also observed in NMP in the treatments which received different times of application. The NMP in the three-year applied treatments was 5, 2.5 and 2.1 times greater than that of control, two- and one-year applied soils. Significant correlations were observed between NMP and corn yield (r=0.531**) and corn N uptake (r=0.568***). The product of NMP and N mineralization rate constant was also significantly correlated with corn yield (r=0.710***) and corn N uptake (r=0.734***). Different patterns were observed between the responses of total N and NMP in the treated soils.
Page 1 /401174
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.