Z. Hadian, M.h. Azizi,
Volume 12, Issue 43 (4-2008)
Abstract
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 (MRLS) adopted by FAO/WHO Codex Commision Alimentarius.
M. R. Rigi,
Volume 22, Issue 4 (3-2019)
Abstract
The effects of dissolved organic matter (DOM), derived from compost, on the sorption of simazine by soils were studied using a batch equilibrium technique. Six soils with different organic carbon contents were investigated in this study. Simazine sorption isotherms on soils were described by the linear equation, and the distribution coefficients without DOM (Kd) or with DOM (Kd*) were obtained. Generally, the values of Kd*/Kd were initially increased and then decreased with raising DOM concentrations of 0-65 mg DOC·L in the soil-solution system form. Critical concentrations of DOM (DOMnp) were obtained, and the value of Kd* was equal to Kd. The presence of DOM with concentrations lower than DOMnp promoted simazine sorption on the soils (Kd* > Kd), whereas the presence of DOM with concentrations higher than DOMnp tended to inhibit the simazine sorption (Kd* < Kd). Interestingly, DOMnp for the tested soils was negatively correlated to the soil organic carbon content, and the maximum of Kd*/Kd (Kmax) was correlated positively with the maximum of DOM sorption on the soil (Xmax). Further investigations also showed that the presence of the hydrophobic fraction of DOM evidently promoted the simazine sorption on soils, whereas the presence of hydrophilic DOM fraction obviously tended to inhibit the simazine sorption.
B. Raheli Namain, S. Mortazavi, A. Salman Mahini,
Volume 23, Issue 2 (9-2019)
Abstract
Agriculture production with high quality and adequate income for farmers and the least harmful effects in environment are the main objectives of agriculture optimization. The main objective of this study was ranking, optimization and land allocation of Gonbadkavoos’s Drylands for strategic products such as wheat, barley, oilseed rape and soybean under environment and socio-economic scenarios. Because the available information on fertilizer and pesticide consumption was not sufficient and reliable, this data was collected through face-to-face interviews with farmers. The results showed that some slightly and moderately hazardous pesticides were consumed in study area. In this study, the optimized combination of agriculture products was applied by using the modeling approach and considering environmental and socio-economic aspects in Gonbadkavoos County. This approach uses MCAT software, which is based on multi-criteria techniques and metaheuristic algorithms. The results of the environmental scenario show ed that barley, oilseed rape and soybean, with little difference, had the highest benefit-to-cost ratio and profitability, respectively. The slight difference could be related to the use of fertilizers and pesticides. In the socio-economic scenario, oilseed rape, wheat and barley had the highest benefit-to-cost ratio and land allocation, respectively. The represented approach using the decision support system (MCAT) can help planners to design optimal cropping systems and aid good management of fertilizers and water consumption.
