The relationship between machine and soil
S. M. Seyedan; A. Heidari
Abstract
IntroductionSoil protection against water and wind erosion is of great importance. Since most soils of arid and semi-arid regions of Iran are poor in organic matter and continuous use of conventional tillage (moldboard plow) has increased the severity of soil organic matter depletion and degradation ...
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IntroductionSoil protection against water and wind erosion is of great importance. Since most soils of arid and semi-arid regions of Iran are poor in organic matter and continuous use of conventional tillage (moldboard plow) has increased the severity of soil organic matter depletion and degradation of soil structure. Therefore replacing conventional tillage with conservation tillage (reduced tillage and no tillage) is needed to improve soil structure and increase soil organic matter. Due to the increasing population growth and the limitation of arable land, it is necessary to remove the fallow year in dryland. Legumes are crops that can be in rotation with wheat. Materials and MethodsThis study was conducted to evaluate the effect of crop rotation and different tillage systems on rain-fed wheat farming in Kaboudarahang Township during 2012-2014. The experiment was conducted as split-plot in a randomized complete block design with three replications. In this study, different crop rotations including fallow-wheat rotation, and chickpea-wheat rotation as main plots and different tillage systems including conventional tillage (moldboard plow + power harrow), conservation tillage (chisel plow equipped with roller), conservation tillage (sweep plow equipped with roller) and direct drilling were investigated as subplots.In the economic evaluation of this project, the economic impacts of the treatments were analyzed using the partial budgeting method and the cost-benefit ratio. For this purpose, the difference between treatments income and cost compared with control treatment has been calculated and compared. The differences in the benefits of the treatments are due to the different yields of wheat. Results and DiscussionResults showed:1- The highest wheat yield in the first and second years of the study was 605.3 and 2135.1 kg ha-1, respectively in rotation of fallow wheat.2- In the first year, the highest wheat yield (690.7 kg ha-1) was related to direct planting (no tillage), but in the second year, the highest yield (2268.6 kg ha-1) was related to conservation tillage (sweep blades + roller).3- In the first and second year, the highest value of treatment was related to direct planting and conservation tillage (sweep tiller + roller), respectively.4- In the chickpea-wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. Thebenefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 5.7 and 2.8 rials can be earned respectively. Therefore, economically, these tillage treatments are superior to the control treatment (conventional cultivation).5- In the wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. The benefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 4.2 and 1.3 rials can be earned respectively. Therefore, it is economically justified and these tillage treatments are superior to the control treatment (conventional tillage).ConclusionThe results of this study showed that in the first and second years, economically the direct method and the conservation tillage treatment (sweep blades + roller) were superior to the conventional method, respectively. Therefore, conservation tillage methods can be replaced by the conventional method (plowing with moldboard plow) in dryland farming. Also, in dry years, direct cultivation (no tillage) is a good and economical method.
M. Fereydoni; H. Haji Agha Alizaheh
Abstract
IntroductionAs the world's population grows, more food need to be produced. Plasma technology is one of the methods that can improve plant growth. Cold plasma is effective in increasing growth and germination indices. In this article, the effect of cold plasma based on corona discharge was investigated ...
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IntroductionAs the world's population grows, more food need to be produced. Plasma technology is one of the methods that can improve plant growth. Cold plasma is effective in increasing growth and germination indices. In this article, the effect of cold plasma based on corona discharge was investigated on germination of Adel, Mansur, and Azad chickpea varieties.Materials and MethodsIn the corona discharge method, a relative vacuum should be used. Corona discharge is formed when there are pronounced spatial in-homogeneities in the electric field, in particular, when the electric field exceeds the breakdown threshold in a limited spatial region. This commonly occurs when highly asymmetric electrodes are employed, such as a point and a plane. Thermodynamically corona is a very non-equilibrium process, creating a non-thermal plasma. The avalanche mechanism does not release enough energy to heat the gas in the corona region generally and ionize it, as occurs in an electric arc or spark. Only a small number of gas molecules take part in the electron avalanches and are ionized, having energies close to the ionization energy of 1- 3 ev, the rest of the surrounding gas is close to ambient temperature. Corona discharge is a weakly ionized non-equilibrium plasma based on the avalanche mechanism. If it reaches a close distance with a conductive material or increase the electrical field, it can create longer breakdown streamers and eventually create sparks. The system is designed to convert 220V voltage with a frequency of 50 Hz to 12 kV voltage with a frequency of 9 kHz. Two electrodes with a 2 cm distance are in a vacuum chamber with a negative pressure of 20 pounds per square inch. And the samples are placed between two electrodes. Experiment was performed in form of a.factorial experimental design based on a CRD. In this plan, treatments are randomly placed in experimental units. The type of factorial experiment performed is 3×3×2×2 and multiplied numbers are factor levels. Seed production year factor in two levels, moisture factor in two levels, Seed variety factor in three levels, and exposure duration factor in three levels were examined. Plasma-exposed seeds and non-exposed seeds were grown under the same conditions. The samples were selected completely randomly. The samples were wetted 24 hours before exposure. Then all 18 chickpeas were placed in a dish in order to observe proper repetition. Samples from each dish were exposed to cold plasma under the same conditions between samples for a specified period of time. After exposing the samples to cold plasma, samples of all dishes under the same conditions at 30 °C and 300 lux environmental light were examined for germination evaluation. For this purpose, samples of each dish were placed in a cover of cotton cloth. They got wet every 4 hours. After 48 hours, all samples were examined and the root length of each sample was measured.Results and DiscussionThe results showed that seeds exposed to plasma for 60 seconds had a faster germination speed than those without exposure. Also, seeds that were exposed to plasma for 30 seconds had a longer root length than those without exposure. According to the results of statistical analysis, exposure to cold plasma for 30 seconds has increased root length in Adel chickpea variety up to 12.5% and in Mansour variety up to 18%.ConclusionAfter statistical analysis, appear that root length under the same conditions, during 30 seconds of exposure to cold plasma, is significant at 5% level from non-exposure and 60 seconds of exposure. Microscopic images of samples were examined on the outer surface and inner tissue of seed cell. Studies have shown that the outer surfaces of seeds exposed to cold plasma are smoother, less prominent and smaller contact angle than those without exposure to plasma. This change can increase the hydrophilicity of seeds. But cold plasma had no effect on cell tissue in terms of size and number.
