جستجوی مقالات مرتبط با کلیدواژه « residue » در نشریات گروه « کشاورزی »

Nicosulfuron belongs to the group of herbicides that has soil residue and its residue in the soil cause damage to sensitive crops in crop rotation.. In order to study the nicosulfuron herbicide persistence in the soil under biological and chemical degradation of nicosulfuron herbicide in soil, under controlled conditions, an experiment was carried out in a factorial randomized complete block design with three replications during 2015-2016. The first factor included conditions of sterile and non-sterile soil and fertilizer, the second factor included the application of organic and bio-fertilizers at four levels of cow manure, vermicompost, mycorrhiza (2 % w/w) and control treatment without fertilizer, the third factor also included incubating periods at eight levels 0, 4, 8, 16, 35, 50, 80, 100 days. The results showed that nicosulfuron degradation was chemical hydrolysis under sterile conditions, and was biodegradation and chemical hydrolysis under non sterile conditions. Nicosulfuron degradation rate was not significant difference in control treatment (without organic fertilizers application) under conditions of sterile, non-sterile fertilizer and soil, But increased with application of organic and bio-fertilizers and deacresed residue herbiced. The lowest residue rate was obtained from the application of cow manure under non-sterile (0.01 mg/kg/ day) and sterile 0.03 mg/kg/ day) conditions. The highest and the lowest degradation rate were obtained from the application of cow manure under non-sterile conditions and control treatment under sterile conditions. Also the lowest and the highest half-life was obtained by 15.33 and 38.5 day from the application of cow manure under non-sterile conditions respectively.

Nicosulfuron belongs to the group of herbicides that has soil residue and its residue in the soil cause damage to sensitive crops in crop rotation.. In order to study the nicosulfuron herbicide persistence in the soil under biological and chemical degradation of nicosulfuron herbicide in soil, under controlled conditions, an experiment was carried out in a factorial randomized complete block design with three replications during 2015-2016. The first factor included conditions of sterile and non-sterile soil and fertilizer, the second factor included the application of organic and bio-fertilizers at four levels of cow manure, vermicompost, mycorrhiza (2 % w/w) and control treatment without fertilizer, the third factor also included incubating periods at eight levels 0, 4, 8, 16, 35, 50, 80, 100 days. The results showed that nicosulfuron degradation was chemical hydrolysis under sterile conditions, and was biodegradation and chemical hydrolysis under non sterile conditions. Nicosulfuron degradation rate was not significant difference in control treatment (without organic fertilizers application) under conditions of sterile, non-sterile fertilizer and soil, But increased with application of organic and bio-fertilizers and deacresed residue herbiced. The lowest residue rate was obtained from the application of cow manure under non-sterile (0.01 mg/kg/ day) and sterile 0.03 mg/kg/ day) conditions. The highest and the lowest degradation rate were obtained from the application of cow manure under non-sterile conditions and control treatment under sterile conditions. Also the lowest and the highest half-life was obtained by 15.33 and 38.5 day from the application of cow manure under non-sterile conditions respectively.

Use of cover crops for controlling weeds is an environmental friendly alternative to conventional chemical and mechanical methods. Kohlrabi is a cool-season hardy crop which can be grown in early spring. The crop is well known in Europe and other regions as a health staple in human’s diets. The aim of the present study was to investigate the effectiveness of using sunn hemp and rye cover crops as monoculture or mixed in controlling weeds and improving yield of kohlrabi.

A two-year field study was conducted. Experimental treatments consisted of monoculture rye (Secale cereal L.), sunn hemp (Crotalaria juncea) and their mixture and no cover crop as control.

Cover crops biomass were 379.7 and 473.9 g.m-2 in first and second growing seasons, respectively. Averaged over two years, weed dry weight reduced by 52.6, 42.5 and 45.4 percentage in rye monoculture, sunn hemp monoculture, and mixed cover crops, respectively. Monoculture rye was more effective in suppressing the dominant weeds. Rye reduced lambsquarter, pigweed, and wild mustard by about 44, 60, and 52 percentage, respectively. On average, use of cover crops improved kohlrabi yield by 30%. Sunn hemp followed by mixed cover crops were more effective in kohlrabi yield improvement.

Cover crops provide many ecological benefits. When weed suppression is the main goal of cover cropping, rye with fast growing habit and extensive root system is more efficient. However, legumes or mixture of legumes and grass are more effective in crop yield improvement.

In order to study the effect of Hydromax adjuvant and application of organic and biofertilizers on persistence of nicosulfuron herbicide in soil, an experiment was carried out as a factorial arrangement based on completely randomized block design with three replications during 2014-2015. The first factor included the use of cow manure, vermicompost, biological fertilizer of mycorrhiza with a control treatment, the second factor included the use of 80 and 40 g a.i ha-1 of the recommended dose of nicosulfuron herbicide, and the third factor included the use of Hydromax adjuvant and without adjuvant. To determine nicosulfuron soil residue after herbicide spray, soil sampling was done from 0-15 cm depth of soil at different periods of 0, 2, 5, 8, 16, 30, 60, 90 days after spraying and then the herbicide residue was determined using both HPLC. Results showed with increasing of nicosulfuron rate, it’s soil residue increased. By increasing the rate of herbicide application, degradation rate decreased from 0.039 to 0.037 μg/kg/day, but half-life increased from 17.77 to 18.83 days. Also nicosulfuron degradation rate decreased from 0.037 to 0.034 μg/kg/day, and half-life increased from 18.73 to 20.39 days in soil when Hydromax adjuvant applied with nicosulfuron at 80 g a.i ha-1.

The residual of pesticides in the agricultural production is endangering human health and environmental balance. Concerns about pesticide residues and environmental impacts due to repeated use of pesticides has led to investigations of the residue and fate of these agents. The adverse effects of pesticideschr('39') residue on humans and the environment have increased interest in genetic engineering technology and cultivation of genetically modified crops for pest management strategies. This study was carried out to investigate the residue of permethrin (EC 25%) in a Vendor cultivar of tomato in greenhouse.  Tomato plants were sprayed at doses of 0.5- 1 g/lit. Samples preparation was performed by the QuEChERS method. Further purification was achieved using a silica solid-phase extraction (SPE) cartridge and pesticide residues were analyzed using GC-MS. This study revealed that residue decreased in descending order. Results showed that the Permethrin (0.5, 1 g/lit) levels were detected below than maximum residue level (MRL) recommended by codex (0.5 mg/kg) at 5 and 7 days after application. Permethrin levels (1 g/lit treatment) were detected below MRL 10 days after application.

In order to achieve a conservation agriculture, a new strip tillage implement was designed that could be pulled with a drill by tree point hitch attachment in order to make possible tillage and planting practices simultaneously. The developed drilling machine was then used and compared with other tillage methods. An experiment was designed using Randomized Complete Block (RCB) with three replications. Main plots were: The four tillage and planting methods namely: moldboard plow 2 passes of disc leveler drill (T1), 2 passes of disc leveler drill (T2), chisel packer drill (T3) and strip-till-drill (T4 or STD), and the subplots namely: seed density of 160 (S1), 200 (S2) and 240 (S3) kg.ha-1 were the experimental conditions.. Evaluated indices were fuel consumption rate, operation time, field capacity and residue pulverization rate. The results showed that T4 treatment had the lowest fuel consumption and time with 8.6 lit.ha-1 and 1.62 h.ha-1 rates, respectively. T1 and T4 treatments with 0.2 and 0.62 ha.h-1 had the highest and the least rates of field capacity. Residue pulverization was 46.47% in T4 treatment and was not significantly difference with T2. Crop yield in T4 treatment was 11% higher than average of other treatments. Finally it was found that tractors with medium power such as MF285 (with 53 kW engine power) could pull this implement.

More than 7 thousand hectares of wheat and barley fields, in Isfahan province, and 200 thousand hectares of wheat and barley fields in Fars province has been infected by wild barley (Hordeum spontaneum Koch.). Wild barley is an annual, winter, diploid (2n = 14) plants, with the fragile axis and self-pollinating flowers. Wild oat seeds, after being separated from the mother plant at a depth of 1-3 cm left, and later in next winter sprouted. Conservation tillage and crop rotation are including the components of integrated weed management. Crop rotation because of a certain type of plant and its associated management of weeds in the rotation can provide a different habitat for weeds. Summer and winter plant crop rotation, plant diversity in a crop rotation, the use of reduced tillage systems and attention to the impact of plant residues, including those that are important in rotation. Tillage methods are considered as a way to control weeds. Although most researchers have agreed to increase the number of weeds in reduced tillage systems due to scattered non-sexual organs, in the case of annual weeds, some researchers believe the rise, and some believe that reducing the number of weeds in reduced tillage systems.
To study changes of weed density of weeds in wheat, especially wild barley, a three-year study (2011 to 2014) by using split plot randomized experiment based on a randomized complete block design with three replications was conducted in the Ardestan city. Main factors were different tillage systems including conventional tillage (moldboard plow use), minimum tillage (using a field cultivator) and no-tillage and six different rotations formed the sub plots. The use moldboard plow tillage with a depth of 25 cm has full buried seeds of wild oats. No tillage system without disturbing the soil, weed seeds will be exposed to the outside environment. The area of the sub-plots of 16 square meters (4 × 4) and an area of about 250 square meters for each replication, which, considering the distance between replication, as well as streams of water the total experiment was 1400 square meters. Seed varieties, were obtained from Seed and Plant Improvement Institute. In every year, wheat grain yield, weed dry weight and density of weeds in different rotations was carried out. Dominant weeds in the experiment were wild barley, wild oat (Avena fatua L.) and Phalaris (Phalaris spp). Other weeds that were less dense and less distribution in experiment and classified as other weeds were: barley mouse (Bromus spp), wild mustard (Sinapis spp), Lepidium Draba (Cardaria draba L.) and wild millet (Setaria spp). Statistical analysis was conducted by using SAS software and statistical tests were compared with Duncan at 5 percent.
In the first year of experiment the effect of tillage on the number of wild barley density, wild oats dry weight, Phalaris dry weight, Oats dry weight (all at 5%) and the number of stem Wild Oats (at 1%) was significant statistically. The results showed in the growing season of (2012-2013), conventional tillage systems and barley cropping in the early rotation, respectively, with 5.33 plants, 13.33 stems and 33.33 g dry weights per square of wild barley showed the lowest amounts compared to the other plants in beginning of rotation and also fallow periods. Similar trends were observed for the other tillage systems, except that the amounts of plant, stems dry weight of wild barley in no-tillage were higher than the other two systems. In the crop year of (2013-2014) maximum dry weights of wild barley (284.3 g m-2) was observed in the conventional tillage system and wheat crops in (canola - corn - wheat) rotation, respectively. The number of weed species present in the first and second year crops was respectively 3 and 7 species. In no tillage system compared with cultivator system, wild barley spike length was not significantly different, but in comparison with the moldboard was 13% longer. A similar trend was observed in the number of seeds produced by wild barley, and wild barley seed per square meter in no tillage systems was 40% higher. With regard to the initial contamination wild barely per square meter was 250 seeds per square meter, wild barely seed production after three years (two cropping seasons) and three moldboard plow tillage systems, field cultivator and soil tillage was still a considerable amount and can be a source of pollution for the next year. In simple terms, similar to the present study, short-term rotation despite the positive trend is still not a complete management to control this weed. In summary, the use of conventional tillage systems and the cultivation of crops belong to Poaceae family (except of barley) can be considered as factors increasing wild barley.

To study effects of nicosulfuron herbicide in soil on wheat, barley and rapeseed after corn harvesting, a field experiment was conducted at the research fields of Ferdowsi University of Mashhad, Iran. The experimental design was arranged in completely randomized blocks design with factorial arrangement of treatments with three replications. The factors included organic fertilizers at 4 levels (cow manure at 40 tons ha-1, vermicompost at l0 tons ha-1, 250 g m-2 mycorrhiza and control treatment without fertilizer). Nicosulfuron (Cruz®,4% SC) rates included 40 and 80 g ai ha-1, with and without the adjuvant (HydroMax™) at 0.5% (v/v). Each plot was divided into two halves with and without the herbicide application, in the corn farm. After harvest of corn, each plot was divided into three longitudinal sections and canola, wheat and barley were planted in each section. Results indicated that plant height, number of ears or silique per square meter, number of seeds per ear or silique, 1000-grain weight, shoot biomass and grain yield of rapeseed, wheat and barley significantly reduced when herbicide was applied at recommended dose. The addition of HydroMax with nicosulfuron, reduced aboveground biomass of mentioned crops, significantly. While organic matter decreased herbicide residue of nicosulfuron and increased plant growth. However, the highest seed yield and the lowest percentage of damage were 63, 419 446 g m-2, and 33%, 23%, 28% in rapeseed, wheat and barley respectly, when cow manure was used plus nicosulfuron at 40 g ai ha-1. In this study, crops sensitivity to soil residue of nicosulfuron herbicide in soil was ranked as rapeseed> barley> wheat.

Mulch tillage system is an intermediate system which covers some of disadvantages of no tillage and conventional tillage systems. In farms in which tillage is done with a chisel plow, runoff and soil erosion have a less important relation to moldboard and disk plow and naturally absorption of rainfall will be developed. Thus, the mulch tillage system is an appropriate alternative to conventional tillage and no tillage (Backingham and Pauli, 1993). The unwanted vibration in machinery and industry mainly processes most harmful factors, for example: bearing wear, cracking and loosening joints. And noise is produced in electrical systems by creating a short circuit (Wok, 2011). Self-induced and induced vibration are used in tillage systems. Induced vibration is created by energy consumption and self-induced vibration is created by collision among the blades and soil at the shank (Soeharsono and Setiawan, 2010). A study by Mohammadi-gol et al. (2005) was conducted. It was found that on the disk plow, plant residues maintained on the soil are more than that of moldboard plow. 99% frequency and amplitude, speed and rack angle of blade directly affect soil inversion and indirectly affect preservation of crop residue on the soil. The effect of vibration frequency and rack angle of blade to reduce the tensile strength is also clear. Moreover, in contrast to previous studies when speed progressing is less than (λ), not only the relative speed (λ), but also frequency can reduce the tensile strength (Beiranvand and Shahgoli, 2010; Awad-Allah et al., 2009). Therefore, aim of this study was to determine the effect of vibration and the speed of tillage on soil parameters and drawbar power in using electric power. To perform this test, three different modes of vibration (fixed, variable and induced vibration) and two levels of speed in real terms at a depth of 20 cm were used for farming. The test was performed with a split plot and randomized complete block design and three replications, and the fixed factors were: the depth of tillage: 20 cm, soil moisture: 16 to 17 percent and rack angle: 15 degrees; and the variable factors were the rate of progress in both 4.5 and 7.5 kilometers per hour and six levels of frequency, 1 fixed (zero) 2 variables (self-induced), 3 (positive19) and 4 (negative19), 5 (positive37) and 6 (negative37) Hz were performed. An electric generator was used to create vibration power. The equation (1) was used to calculate the vibration power: (1) Where P: Electric power (W), V: voltage (V), I: current (amps) and Ǿ: phase angle (degrees) between the voltage and current. After the calculation, the required power of 19 Hz was calculated to be 0.6, and the required power of 37Hz, was calculated to be 0.75 kilowatts, respectively. The sample of mean weighted diameter, after tillage in each plot, was about 10 kg soil (0 to 20 cm depth) with 3 replicates and through the equation (2), mean weight diameter was calculated as follows: (2) Where MWD: Mean weight diameter (cm), Xi: Two Elk consecutive mean diameters (cm) and Wi: weight ratio of the soil remaining on the sieve to the total weight of the sample. In order to calculate the specific energy tension due to the width of tillage (28 Cm), equation (3) was used. (3) Where E: tensile special energy in kilojoules per square meter, P1: drawbar pulling power required in kW, P2: the vibration according to equation (1) based on kilowatt, T: tillage time in one square meter per second. According to analysis of variance (Table 2) interaction effects of frequency and speed to keep the residue are significant at 1%, and this situation was shown well in Fig.2 Therefore, in practice, with increasing frequency in both induction and self-induction vibration, the tillage blades created a groove at the soil surface with less turmoil, and this would maintain the maximum residue on the surface of the soil. As is clear from Fig.3, treatment of the frequency of 37+ (code 5) in both the first and second average forward speed is highest in remaining residue with 85% and 74%, respectively (Liu and Chen, 2010) and (Awad-Allah et al., 2009). By applying induced vibrations, a significant reduction in tensile strength occurs, because it reduces the time to deal with the blade of soil tillage and soil fractures with blows of the blade. It is clear that vibration reduces slip and real wheel speed is progressing, and following it, the increase in tensile strength occurs and it should not be considered due to the in efficiency of vibration tillage, since vibration may increase the depth of tillage, with the same vertical force component (Sahaya et al., 2009). Specific energy (plus drawbar and vibration) are shown in Figure.5 and the lowest energy consumption in both the first and the second speeds was on treatment of frequency +19, being 18.9 kJ m and 23.2 kJ m to first and second speeds, respectively. In general, both factors (vibration and speed) affected tillage parameters and energy consumption and induced vibration caused by the system of unequal mass and electrical power properties was very easy to change phase vibration and transfer of power. This study was designed because of the significant effects on the important parameters of quality by vibration frequency of tillage and different frequencies to control the way in which tillage parameters are controlled. We can take it as a precision tillage that introduced variable control rate of percent residue on the soil, clod mean weight diameter that is suitable for the cultivation combined with reduced energy consumption.

Due to the reduction of non-renewable resources, increased global demands for providing energy, seems essential in the present circumstances. Beyond the pyrolysis process, biomass has this ability to become bio-energy (biochar) as a renewable resource. Biochar is known as a mean for carbon sequestration, reducing greenhouse gas emissions, uses as a renewable energy and also for improving soil structure and fertility. Fewer studies have been conducted on its quality benefits in agronomy. The amount of chemicals which are applied in agriculture and the risks of ground water resources contamination are the important issues in all aspects of life levels. Herbicides are commonly used in agriculture and they have this ability to penetrate and leak into the deeper layer of the soil and then groundwater resources, hence, they can cause irreparable hazards on the on quality of living organisms. Previous Studies showed that use of biochar on the soils could increase sorption and reduce the leaching of herbicides. Therefore, the effects of various biochar on uptake and leaching of herbicides can be illustrated as an appropriate way to reduce contamination by these chemicals.

Inappropriate application of pesticides and their subsequent residuals in agricultural products have increased concerns about their health hazards. In order to measure the residue of the most common pesticides applied on cucurbit, tomato, cherry, grape and apple, this study was conducted in Khorassan Razavi province. Samples were collected from the major cultivation regions of above mentioned crops. According to the type of the products, extraction was performed by QuEChERS method. The extracted substances were injected to gas chromatography-mass spectrometer (GC-MS) to detect various pesticides. The results were evaluated according to the national standard. Pesticides residue from cucurbit were: malathion, oxydemethon methyl, diazinon, dichlrovos, metalaxyl, fenpropathrin, and propargite with the average rate of 5.09, 3.33, 0.18, 0.43, 2.38,. , and 6.32 mg kg-1; tomato: fanpropatrin, azinphos methyl, diazinon, phosalone, with the average rate of 7.65, 0.16 and 0.235, 0.1 mg kg-1; from cherry: diazinon, malation, fenitrothion, with the average rate of 11.2, 0.79 and 1.57, mg kg-1; from Grape: ethion, malathion, and diazinon, with the average rate of 2.4, 12.46 and 0.48, mg kg-1; and apple: ethion and fenitrothion with the average rate of 1.59 and 0.06 mg kg-1, respectively.Key words:

Pesticides are found in fresh fruits، vegetables and different processed products as well. In this research، diazinon residue in tomato and also effect of different processes in tomato paste production on residue amount was studied. Applying HPTLC method، measurement of the pesticide residues was carried out on arrival، before washing، after washing and rinsing، in the juice، after concentration، and in the tomato pomace. In this study two different kinds of spiking on the tomato fruit was used: Immerging of tomatoes into 2 ppt solution of diazinon and water for one and ten minutes. Samples were analyzed in triplicate and the standard deviation was 2. 63. Effect of chlorination on reducing the pesticide residues level was also measured after ten minutes dipping. Experimental results revealed that diazinon residues in tomatoes after one and ten minutes dipping were 16. 56 and 19. 8 μg/g، respectively. Effect of different processes during tomato paste production on residue amount after one and ten minutes dipping were as follow: after washing was 13. 04، 16. 6 μg/g، in the juice and in the tomato pomace samples was 12، 13. 68 μg/g and 30. 52، 39. 96 μg/g. tomato paste sample was 8. 84 μg/g for ten minutes dipping. Effect of chlorination on reducing the pesticide residues level of measured 24. 96 μg/g، for ten minutes dipping.

To evaluate the sensitivity of different crops included some pulses to simulated metribuzin soil residues, an experiment was conducted in completely randomized design with factorial arrangement and four replications in Research Greenhouse of College of Agriculture, Ferdowsi University of Mashhad. Treatments included of 8 crops (chickpea, common bean, lentil, corn, wheat, barley, rape seed and sugar beet) and concentrations of metribuzin simulated residue in soil at 6 levels (0, 0.016, 0.032, 0.064, 0.128 and 0.160 mg a.i. kg-1 soil). Plants survival percentage and shoot and root biomass were measured 30 days after emergence. Plants response to metribuzin soil residue fitted with 3 and 4 parameters logistic equations to the shoot and root biomass data as a function of the herbicide soil residue concentrations and was used to calculate the dose for 50% of measured traits (ED50). Results showed that the survival and shoot and root growth were affected by metribuzin soil residue, significantly (pchickpea>common bean>corn.

Widespread use of herbicides throughout the world plays an important role in water and soil pollution. Hence، knowledge of the behavior of herbicides is necessary to reduce their adverse effects on the environment. An experiment was conducted in RCBD with a factorial arrangement of treatments and 3 replications to study the effect of manure and herbicide application rates on trifluralin dissipation in soil. The factors were two amounts of animal manure (0 and 25 ton ha-1) and three application rates of trifluralin (0. 48، 0. 96 and 1. 92 kg ai ha-1). Sampling from the soil was carried out immediately and 7، 14، 28، 48، 90 and 120 days after applying the trifluralin and the herbicide residues were measured using HPLC. Dissipation of trifluralin followed first-order kinetics in the soil and its rate was higher in the amended soil independent of the application doses or cover state. A maximum dissipation rate of 0. 032 mg kg-1 ha-1 was observed in no manure and of 0. 48 and 0. 96 kg ai ha-1 of herbicide; a minimum dissipation rate of 0. 012 mg kg-1 ha-1 was observed in the manure treatment and of 1. 92 kg ai ha-1 for trifluralin. A maximum half-life (57. 75 days) was related to the manure treatment and 1. 92 kg ai ha-1 for trifluralin، and a minimum half-life (21. 38 days) was related to the no manure treatment and 0. 48 kg ai ha-1 for trifluralin. According to the findings of this experiment، the persistence of trifluralin in soil is increased by increasing the application rate of the herbicide and applying manure. It is likely that manure utilization increases trifluralin absorption into the soil which probably results in a reduction in herbicide evaporation.

This study is an objective effort to investigate the role of wood and paper industries management in application of agricultural wastes and residues. The role of wood and paper industries management of country in sustainable development and upcoming chanlenges (including growing population and over exploitation use of sources especially forest resources, environmental pollutions, importance of sustainable development as an ensuring factor of food safety and generations rights) has discussed in present work. Therefore, the amount of agricultural residues usage in pulp and paper industries in Iran was compared, and in addition to expression of general concepts of sustainable development, following propagative approaches introduced to planners and policymakers of wood industries: training people in optimal use of raw materials, management of agricultural residues and use of these materials in the construction of composite materials, correction of management procedures in forest and waste reduction during operational stage, government support for forest planting of fast growing species, utilization of waste papers through recycling and reprocessing in paper industries, support for NGOs active in environment and recycling, cultural works and public enlightenment to clarify the statues and worth of forest and rangelands and sustainable management.