Precision Farming
N. Salehi Babamiri; H. Haji Agha Alizadeh; M. Dowlati
Abstract
IntroductionSoil surface roughness is an important factor in determining the intensity and quality of tillage operations, and obtaining accurate information essential for precision tillage. Using an inappropriate technique due to the lack of precise discrepancy detection can lead to increased time spent ...
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IntroductionSoil surface roughness is an important factor in determining the intensity and quality of tillage operations, and obtaining accurate information essential for precision tillage. Using an inappropriate technique due to the lack of precise discrepancy detection can lead to increased time spent on analysis and potential damage. Generally, there are two methods for measuring soil surface roughness: contact and non-contact. Contact methods are less accurate for measuring the roughness of soft soil because they involve physical contact, which can partially disturb the soil. Most non-contact measurement methods are also performed in stop-and-go conditions, which increases measurement time and related analysis. The aim of this study is to measure soil surface roughness in real-time using optical sensors in the field. The accuracy and precision of two non-contact measurement methods will be compared to determine the best approach for precision tillage operations.Materials and MethodsIn the current research, a real-time soil surface roughness measurement system consisting of mechanical and electrical modules, data collection, and processing was built. The system performance was evaluated at different forward speeds and roughness categories, with two types of infrared and laser sensors. To assess the sensors’ accuracy, the collected data was compared against the pin gauge method, which served as the reference standard. The method exhibiting the least variation from this reference is considered to provide the most reliable data. Also, to further examine the accuracy of the sensors, the roughness data obtained from the sensor at various frequencies was compared against the roughness data obtained from the pin measuring device at the same level, resulting in a suitable curve plot. The interpretation of the obtained mathematical relationship indicates the precision of the sensor data.Results and DiscussionThe results obtained from the optical sensors were compared to the pin meter, used as the reference method, in both stationary and moving conditions. It was demonstrated that the optical sensors detect distance in the static state similarly to the reference pin meter. The calibration curve interpretation factor was 0.99 for the infrared sensor and 1 for the laser sensor, indicating a strong correlation between the sensor signals and their distance from the soil surface. The random roughness index was significant for different roughness classes at the 1% probability level, showing that this index effectively distinguishes between the resulting roughness classes. Analysis of variance results revealed that the measurement method had a significant effect at the 1% level. The method with the smallest difference from the reference method is considered the most appropriate measurement technique. The effect of forward speed was also significant at the 1% level; the speed at which the sensor’s performance did not significantly differ from the reference method was identified as the optimal speed for the system. Additionally, the effect of roughness class was significant at the 1% level, confirming that the created roughness classes had meaningful differences. The results of the sensor accuracy evaluation showed that the data obtained from the laser sensor at speeds of 1 and 2.6 km h-1 had no significant difference with the reference method. Therefore, it is appropriate to use the laser sensor at speeds of 1 and 2.6 km h-1. At speeds higher than 3.5 km h-1, the laser sensor successfully detected smooth surfaces, but did not correctly distinguish uneven surfaces. In general, the laser sensor was able to detect all categories of roughness at a speed of 2.6 km h-1. One reason the laser sensor did not perform well at speeds above 2.6 km h-1 was its low data acquisition rate. By using laser sensors with a higher data collection rate, the soil height profile can be plotted similarly to a pin scale. The infrared sensor was successful only in detecting smooth surfaces but failed to detect other types of surfaces.ConclusionDue to limited accuracy and the risk of damaging or altering the surface roughness, the contact method is not recommended for use on soft soil surfaces. Among non-contact methods, the most suitable technique is the one that provides the highest accuracy and precision while minimizing cost and time for data collection and analysis. In this study, two types of sensors including laser and infrared ranging were selected based on their reasonable price, ease of operation, compatibility with a mobile system, and ability to deliver real-time roughness measurements in the shortest possible time. The results demonstrated that real-time measurement of soil surface roughness can effectively replace traditional, tedious, and time-consuming methods.
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.
