Showing 11 results for Availability
M. R. Ebadi, J. Pourreza, M. A. Edriss, J. Jamalian, A. H. Samie, S. A. Mirhadi,
Volume 10, Issue 4 (1-2007)
Abstract
In order to assess and determine amino acids profile and their availability in different sorghum grain (SG) varieties, three SG varieties including low tannin (0.09% , LTS), medium tannin (0.19%, MTS) and high tannin (0.37%, HTS) were grown at the same location. The grains were analysed for their proximate analyses, tannin and amino acids. True amino acid availability (TAAA) was obtained by Sibbald’s method using ceacectomized single comb leghorn cockerels. The results showed that methionine and cystine were the first and the second limiting amino acids, respectively in LTS and MTS. But in HTS, lysine (0.166%) was the first and methionine (0.176%) was the second limiting amino acid. Methionine content was 0.114% , 0.182% and 0.176% for LTS, MTS and HTS, respectively. Although, crude protein was lower in HTS (10%) than the other SG, but histidine, methionine and isoleucine were higher for HTS in comparison to LTS and MTS. TAAA decreased when tannin content increased and all amino acids had a lower availability in HTS than LTS and MTS (P<0.05). Methionine in HTS and LTS and glutamic acid in MTS had the highest availability. The availability of proline was most affected by tannin, and its availability was 91.55% for LTS, 84.82% for MTS and 22.82% for HTS (P<0.05).
A. Moshgeli , J. Pourreza, A. Samie,
Volume 12, Issue 43 (4-2008)
Abstract
This experiment was conducted to determine the phosphorus relative bioavailability of eight samples of dicalcium phosphate. Bioavailability of Samples of dicalcium phosphate was evaluated and their effects on performance of laying hens were investigated. Commercial samples of Dicalcium Phosphate were provided from the following manufacturers: Iran Phosphate, Partove Bashash, Godaze, Poya Khojaste, Dan Razy Kimia, Phosphore Iran, Golbar Shimi and Dan Avar. The Parameters measured were shell strength, shell thickness, shell ash percentage, shell percentage, shell calcium and phosphorus percentage, Haugh unit, egg weight, egg production, egg output, feed consumption, feed conversion ratio, tibial ash, and tibial calcium and phosphorus. One hundred and six, and 36 weeks old white Leghorn hens, from strain Hi-line W-36, were randomly allocated to 8 dietary treatments and 4 blocks in a completely randomized block design. The experiment lasted for 3 months, starting in the 36th week and ended in the 48week of age. Shell thickness, shell ash percentage, shell percentage, feed consumption, tibial ash and tibial calcium percentage were significantly different (P< 0.05) among treatments. Effect of experimental period on shell calcium and phosphorus percentage, egg weight, egg production, feed consumption, egg output was significant (P< 0.05). Relative bioavailability of samples ranged from 85 to 105.7%. Overall, samples of Phosphate Iran (F) were considered most effective with regard to relative bioavailability and performance.
M. Boyerahmadi, F. Raiesi , J. Mohammadi,
Volume 14, Issue 51 (4-2010)
Abstract
Similar to plants, soil salinity may reduce microbial growth and activities in different ways. The aim of this study was to determine the effects of different levels of salinity on some microbial indices in the presence and absence of plant's living roots. In this study, five levels of salinity using NaCl, CaCl2, MgCl2 and KCl and three soil media (soil with no plant, soil cultivated with wheat and clover) replicated three times consisted our factorial experiment arranged in a completely randomized design. Results show that salinity caused a significant reduction in accumulated microbial respiration, microbial biomass carbon, substrate-induced respiration, and carbon availability index in uncultivated soil and in the soils planted with clover and wheat. Results also show that salinity caused a significant increase in metabolic quotient (qCO2) in uncultivated soil, and soils planted with clover and wheat. Microbial activity of cultivated soils at high salinity levels was almost similar to that of the uncultivated soils. We observed a small difference in soil microbial activity among the three media at high salinity levels, indicating the role of indirect effects of salinity might be less important with increasing salinity levels. We also found out that at low salinity levels, the available carbon was not a limiting factor for soil microflora, while at high salinity levels the activity of soil microbes might be carbon-limited. The lower values of qCO2 in cultivated soils compared with the uncultivated soil support the positive influence of root and its exudates on soil microbial activity in saline soils. The existence of plants in saline environments may help in alleviating the detrimental influence of low to medium salinity on most soil microbial activities, likely via the added root exudates and root turnover.
M. Zolfi Bavariani , M. Maftoon ,
Volume 14, Issue 54 (1-2011)
Abstract
Due to low availability of zinc and copper in calcareous soils and the antagonism of these nutrients with each other, the study of their effects on growth and chemical composition of rice seems to have great importance. Also, the relations among different chemical forms of Zn and Cu and plant responses are very important, which can be used in investigation of antagonisms of these nutrients as well. Therefore, by application of different levels of Zn and Cu, their effects on plant growth and nutrient concentration in the plant were studied and different forms of these nutrients in soil were determined. Results showed that zinc application increased plant growth, Zn concentration and total uptake, but decreased Cu concentration in the plant. However, copper application showed no significant effects on the plant growth, but increased Cu concentration and total uptake and decreased Zn concentration in the plant. Also, the results showed an increase in carbonatic, adsorbed and exchangeable Zn forms and exchangeable Cu form by Zn application. Carbonatic form of zinc has maximum effects on concentration and total uptake of this element in the plant. Copper application increased carbonatic and organic forms of this nutrient in soil, and there was maximum correlation between organic form of Cu and its concentration and uptake in the plant
H. Kheirabad, A. H. Khoshgoftarmanesh, Z. Khanmohamadi,
Volume 16, Issue 62 (3-2013)
Abstract
Due to soil and plant zinc (Zn) deficiency and its effect on reducing yield and quality of agricultural products, application of Zn fertilizers has been intensified in recent years. To achieve optimum fertilizer management, knowledge of factors affecting Zn availability in soil and its uptake by plant is required. Therefore, this study was carried out to investigate the effect of certain soil physiochemical properties on Zn availability in soil and its uptake by corn. The experiment was laid out in a completely randomized design with factorial combination and three replicates in the research greenhouse of Isfahan University of Technology, in winter 2009. In this greenhouse experiment, 11 soil series were exposed to two Zn levels (0 and 15 mg Zn kg−1 in the form of zinc sulfate). The results indicated that Zn application significantly increased the dry matter weight and shoot and root Zn concentration of corn, although the magnitude of this increase varied depending on the soil type. There was no significant correlation between the DTPA-extractable Zn and the uptake of this nutrient element by corn. There was a negative significant correlation (P < 0.05) between the equivalent calcium carbonate content and available P with the DTPA-extractable Zn. A significant linear relationship (R2 = 0.31) was found between the buffer capacity of soil for Zn and clay content. According to the results obtained from the stepwise regression analysis, the DTPA-extractable Zn and buffer capacity of soil for Zn were not correlated with other measured soil properties.
M. Norouzi, A. H. Khoshgoftarmanesh, M. Afyuni,
Volume 18, Issue 70 (3-2015)
Abstract
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.
Msc S. Shahmoradi, Dr M. Afyuni, Dr M. Hajabbasi, Dr A. H. Khoshgoftarmanesh, Dr M. Shirvani,
Volume 21, Issue 2 (8-2017)
Abstract
During last century, waste water of gold mine has accumulated heavy metals such as lead, zinc and cadmium in Zarshuran region soil, and thus has increased epidemic disease in this region drastically. The purpose of this research was to reduce the mobility and bioavailability of zinc, lead and cadmium in rhizosphere of sunflower grown in soil around the mine by inorganic sorbents. A pot experiments was carried out with three levels of raw zeolites (1, 6, 12 wt%), three levels of raw bentonite (1, 6, 12 wt%) and control (without sorbent) in a completely randomized block design with three replications. After cultivation, soil and plant samples were taken and the concentration of lead, cadmium and zinc in their samples were measured. Different levels of bentonite reduced the absorbable concentration of lead and zinc; and also reduced their absorbable concentrations in plant tissue, but had no significant effect on reducing absorbable concentration of cadmium. Transfer factor for all three metals in the roots was more than shoot and reducing the concentration of heavy metals in the plant had no impact on plant growth. According to the study, level of 12 wt% of the raw bentonite was the most suitable sorbent for the stabilization of lead and zinc; and level of 12 wt% for raw zeolite was the best sorbent for stabilization of cadmium.
M. Najafi-Ghiri, Y. Kiassi, F. Khademi, A. R. Mahmoodi, H. R. Boostani, Dr M. Mokarram, M. J. Gholami,
Volume 22, Issue 3 (11-2018)
Abstract
Little information is available regarding the effect of road on the adjacent vegetation and soil. The current investigation was done to study the effect of Darab-Bandar Abbas road on vegetation, soil properties and nutrient availability of the adjacent soils. For this purpose, eighteen soil samples in three different regions from the roadside and the adjacent land (50m from the road edge) were collected and the vegetation type and density were determined. Soil properties and the availability of N, P, K, Fe, Mn, Zn and Cu were also determined. Roadside soil had more organic matter and sand contents and less clay content and pH in comparison to the adjacent lands. The mean contents of N, Fe, Zn and Cu available in the roadside soils were 0.13%, 4.2, 3.2 and 0.7 mg kg-1, respectively; these were significantly more than those of the adjacent lands (0.06%, 2.8, 0.6 and 0.3 mg kg-1, respectively). Vegetation of roadside was more varied, consisting of Artemisia sieberi and Astragalus fasciculifolius. Vegetation cover in the roadside (13.8%) was significantly more than that of the adjacent lands (8.5%). Generally, it could be concluded that roadside soils had a suitable moisture condition and fertility for the vegetation development and this could be considered in the soil conservation management of the roadside soils.
E. Sadeghi, F. Raiesi, A. Hossienpur,
Volume 23, Issue 2 (9-2019)
Abstract
Abiotic stresses such as salinity and contamination individually have a negative effect on the soil enzyme activities, whereas addition of organic matter to soil can alleviate the negative impacts of stresses on the enzyme activity. However, the combined effects of these stresses (multiple stresses) on soil biochemical conditions and the role of organic matter addition in these interactions are largely unknown. The objective of this research was to explore the interaction effect of NaCl salinity and cadmium (Cd)-pollution on the activities of catalase, alkaline phosphatase, arylsulfatase and fluorescein diacetate hydrolysis in a Cd-contaminated calcareous soil treated with alfalfa residue over 3 months of incubation. A factorial experiment with 2 levels of Cd, 3 levels of salinity and 2 plant residue treatments was conducted using a completely randomized design with 4 replications. The results indicated that salinity increased the Cd availability in both uncontaminated and contaminated soils and reduced the soil enzymatic activity. Nevertheless, addition of alfalfa residue reduced the detrimental effects of salinity and Cd-pollution on the soil enzyme activities. This indicated that in saline Cd-contaminated soils with low organic matter, adding plant residues could lower the concentration of available Cd and the effect of soil salinity with a concomitant increase of enzyme activities. So, this study showed that the joint effect of NaCl salt and Cd on enzyme activity was mostly synergistic in plant residue-untreated soils, but it was antagonistic in the plant residue-treated soils.
F. Khafi, A.r. Hossienpour, H. Motaghian,
Volume 26, Issue 2 (9-2022)
Abstract
One of the significant factors affecting biochar properties is the pyrolysis temperature. This study aimed to investigate the effect of pyrolysis temperature on the properties and fractionation of Zn and Pb in biochars produced by sewage sludge. Biochars were prepared at temperatures of 300 to 700 °C and the physicochemical properties, availability, and fractionation of Zn and Pb were investigated. The results showed that pH, pHzpc, percentage of calcium carbonate, cation exchange capacity, specific surface area, and porosity in biochars were higher than in the feedstock. By increasing biochar production temperature, the mentioned properties increased. FT-IR revealed that the OH functional group is present in free form, either in the structure of C-OH and -COOH and aliphatic-CH2 groups in the sewage sludge. By converting sewage sludge to biochar, the intensity of these peaks decreased. In contrast, peaks representing complex aromatic structures appeared. The availability of Zn and Pb in biochar was reduced as compared to sewage sludge. The results of fractionation indicated that sewage sludge has bio-availability and toxicity of Pb and Zn. the amount of oxide and residual fractions of these two metals increased by converting sewage sludge to biochar at different temperatures. Therefore, it seems that biochar production from sewage sludge reduces the toxicity and bio-availability of Zn and Pb. Also, by incrementing the temperature of production, the bio-availability potential (bonding with organic matter), and non-toxicity (residual) of these metals increased.
F. Beigmohammadi, E. Solgi, M. Soleimani, A.a. Besalatpour,
Volume 26, Issue 3 (12-2022)
Abstract
The industrial areas are located near residential centers in the city of Arak and potentially toxic elements (PTEs) pollution is a serious threat to human health and living organisms in this area. Meanwhile, soil contamination by PTEs is one of the challenges in this region and various studies have been conducted in this area. Meta-analysis studies provide a comprehensive evaluation of the results of a subject. In the present study, soil contamination data for PTEs in the 11 years (2009 to 2020) were studied through the studies conducted in Arak. In this study, the risk, potential toxicity, and carcinogenic and non-carcinogenic risks of PETs were assessed using indices and mathematical relationships. Based on the results of pollution indices, the soil of Arak city in terms of PETs including Zn, Cd, Cr, Ni, As, Pb, Cu, and Hg were categorized into the polluted and highly polluted classes. The soil of the region in terms of PETs has significant ecological risk and acute toxicity. Cadmium, arsenic, and mercury showed the ecological risk of 49.3%, 23.2%, and 18.3% respectively, and nickel, chromium, and arsenic were responsible for 34.7%, 23.03%, and 22.07% of the toxicity potential of PETs in the soil. Arsenic, nickel, and chromium have the highest carcinogenic risk for children in both the ingestion and inhalation pathways, and chromium, arsenic, and nickel have the highest carcinogenic risk from the inhalation pathway for adults. According to the results, the most considerable PETs in the study area including As, Cd, and Pb, and the most important source of their emission in Arak are anthropogenic resources and industries.
