نشریه مکانیزاسیون کشاورزی
سال هشتم شماره 2 (تابستان 1402)

Determining the exact rate of wheat loss in wheat purchase centers is one of the concerns of the government to ensure farmers' fair purchase of wheat. In this research, the performance of four types of separator sieves with 2×2, 2×20, 1.7×20 and 1.5×20 mm grids was studied for separation of impurities in irrigated and rain-fed wheat cultivars in Kermanshah, Fars and Semnan provinces in moderate regions in terms of qualitative, technical and financial. The results showed that in the case of wheat sieving with a 2x20 mm sieve, the highest amount of protein and zaleny sedimentation volume was observed, although these changes in bakery properties, including grain hardness, were not significant. In addition, samples sieved with 1.5 x 20 mm sieve had the lowest Falling number. the average useless loss for irrigated and rainfed wheat varieties was 1.55% and 1.61% and the average useful loss for wheat varieties was with mesh 2×20, 1.7 × 20, 2 × 2 and 1.5 × 20 mm was 4.7%, 1.85%, 0.6% and 0.084%. By changing the separation sieve from 2×2 mm mesh sieve to 2×20 و and 1.7×20 mm mesh sieves, the useful loss rate increased and the financial value of wheat purchased in the purchase centers are coming down. Also, in the preliminary separation of impurities (weed seeds), 2×2 mm mesh sieve was more efficient than other sieves. Thus, the use of 2×2 mm mesh sieve to determine the useful loss of wheat in purchase centers can be useful and beneficial to farmers

Design of new tools for pruning hedges cultivated with a shrub like wild privet can have a great impact on the quality of pruning and their appearance in parks. The movement of wild privet stalk during cutting is considered one of the issues of pruning when using common tools, which usually causes uneven pruning. In order to design a new pruning tool, it is necessary to know the shearing mechanical properties of the stalk, such as shear force, cutting energy and shear strength of the stalk. To determine them, a series of a series of experimental tests were performed. The parameters such as shear force, cutting energy, and shear strength were determined with two quasi-static and impact cutting methods in three cutting positions of the fifth, tenth, and fifteenth internode position. In the quasi-static cutting test, the stem samples were subjected to cutting with four cutting speeds of 5, 10, 15, and 20mm/min, and in the impact cutting test, the samples were subjected to cutting with four speeds of 1, 2, 3, and 4m/s. The average moisture content of the samples at the time of the experiment was measured at 75% on a wet basis. The results of quasi-static stalk cutting showed that cutting speed had a significant effect on the parameters of shear strength (P<0.01), and cutting energy (P<0.05), and the stalk cutting position had a significant effect on shear strength (P<0.05), and cutting energy (P<0.01).

The water shortage crisis necessitates the implementation of new technologies to increase water productivity. The aeroponics and hydroponics methods can be part of these technologies. In this study a high pressure aeroponics system including two separate units was designed and constructed for conducting research experiments. In this technology, the roots of the plant were suspended in a horizontal arrangement in the air and subjected to periodic spraying of the nutrient solution. The nutrient solution based on Hoagland's formula was transferred by a diaphragm pump and after passing through the filter, it was sprayed on the roots of the plants through the nozzle at regular intervals. Other equipment such as pressure switch, pressure gauge, drain valve, programmable timer, and diaphragm accumulator were used in the hydraulic circuit of the system. The sprayed solution was collected at the end of the chamber and returned to the tank due to the gravity force. The design was such that there is always some solution in the bottom of the tank and the roots can use this solution as well, so this system can be considered as a hybrid type. The results showed that this hybrid method significantly increased leaves and root growth compared to the traditional method. The systems built in this research are part of the path to better use of agricultural water and still need to be optimized. Due to the development of vertical farming and urban agriculture in the world, aeroponics systems can play a significant role in this regard.

Energy consumption has increased directly and indirectly in the agriculture sector to meet the needs of growing population. Regarding the scarcity of production resources including energy, the present study aimed to measure the technical efficiency of rainfed wheat farms and its effective factors. For this purpose, the required data collected from 217 farmers in Ahar county and input and output (wheat) quantities converted to energy equivalents. The results of estimating the translog stochastic frontier production function along with the inefficiency function showed that the energy factors of labor, pesticides and machinery have a significant effect on output energy of wheat. Meanwhile, factors such as distance from fields to village, land slope, number of rainfed wheat farms and the cultivated land of wheat are affective on inefficiency use of energy. The mean of energy efficiency of wheat producers was 51%. Therefore, the output energy can increase by 49 % if efficient use of input energy and principal component of field operation followed. Considering the existence of suitable methods for improving energy efficiency is recommended with increasing information of farmers, holding extension courses and applying modern technologies

This work presents estimates of the emissions resulting from the production of sugar beet from Consumption of inputs in cultivation to the final product at the farm gate. Life cycle assessment method was used. The study covers the impact of abiotic and fossil depletion potential, acidification potential, eutrophication potential, global warming potential for time horizon 100 years, ozone depletion potential, human toxicity potential, freshwater and marine aquatic ecotoxicity potential, terrestrial ecotoxicity potential, and photochemical oxidation potential. The results of this analysis are presented for the functional unit of 1 tonne sugar beet without allocation. Abiotic depletion, abiotic depletion (fossil fuel), acidification, eutrophication, global warming, ozone depletion, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity, and photochemical oxidation were calculated as 3.78×10-4 kg Sb eq, 3.57×10+3 MJ, 310 kgCO2 eq, 8.25 ×10-6 kgCFC-11 eq, 37.70 kg 1,4-DB eq, 47.40 kg 1,4-DB eq, 5.45×10+4 kg 1,4-DB eq, 1.72 kg 1,4-DB eq, 5.37×10-2 kg C2H4 eq, 3.16 kg SO2 eq, 1.73 kg PO4 eq, respectively. Almost all impact categories were dominated by electricity and chemical fertilizers. Replacing grid electricity as the main source of irrigation energy source with renewable electrical energies reduced the environmental burdens for sugar beet production. Due to the limited water resources in Iran, changing and improving the cultivation pattern on micro and macro scales can significantly affect the environment.

Wheat is one of the most important crops in the country and plays an essential role in meeting the food needs of the people.Wheat production is associated with waste, and most of this waste comes from the harvesting stage. The amount of this loss in Iran is more than the world's allowed amount and any effort to reduce this loss can be effective in improving the product's performance. If losses are evaluated using precision agriculture techniques on site-specific, corrective measures can be taken according to each location to reduce losses and increase efficiency. In the present study, an attempt was made to prepare a grain loss map with acceptable accuracy by using a suitable interpolation method. For this purpose, natural, head and rear losses were collected simultaneously with the change in combine settings during harvesting. Then, using kriging interpolation methods, inverse distance weighting and moving average, the mapping of grain losses was done in ArcGIS software. The results of cross-validation and comparison of the accuracy of the methods showed that the mean value of the loss prediction error in all the interpolation methods is close to each other. For example, the RMSE value in the header loss for the inverse weighting method was calculated as 0.006017, which is lower than the values calculated for the kriging and moving average methods, which were obtained as 0.006732 and 0.006095, respectively. According to the results, the inverse distance weighting method is the best interpolation method for creating grain loss maps.