نشریه تحقیقات سامانه ها و مکانیزاسیون کشاورزی
پیاپی 73 (پاییز و زمستان 1398)

The acquisition of basic knowledge in quality control of wheat seed using machine vision technology is important. The objective of this research was to develop hardware and appropriate software to determine seven-grain groups in wheat seed samples. Ninety-one features were extracted through 21000 single seed images and the shape, texture and color features were ranked. Five classification models were investigated. The highest classification accuracy was obtained by artificial neural network with two hidden layers and the first 35 superior features. In the test run of this model with independent data, classifying accuracy for big white wheat, small white wheat, broken white wheat, wrinkled white wheat, red wheat, barley and rye were 100, 96.7, 99.3, 90.3, 99, 99.7, and 98 percent respectively with the average of 97.6 %. Shape features were more prominent and textural and color characteristics followed it respectively. Average classification accuracy in models of linear discriminant analysis, quadratic discriminant analysis, K- nearest neighbor and artificial neural network with a hidden layer were 95, 96.7, 91.6 and 97.3 % respectively. In the context of this study, the machine vision system comprising an industrial digital camera and artificial neural network with two hidden layers was identified as a valuable system in the investigation of the visual qualities of wheat seeds.

In this study, in order to determine the optimal mechanization of the wood primary transportation in the Hyrcanian forests of Iran, current machines including Timberjack 450C, HSM 904 and agricultural tractor and number of new machines including LKT 81, TAF 690, Vimek 610 and Mowi 650 were investigated. The Goal Programming technique, a multi-objective optimization method, including environmental, economic, performance, ergonomics, was used. The results showed that Timberjack 450C and HSM 904 skidders had less log transporting costs compared to other machines, and economically are still cost-effectively machines. For the transporting of firewood, Farm tractor is not cost-effectively and the alternative economic option is Mowi 650 trailer. In the case of replacement, the cost of firewood transporting will decrease by 44%. Optimization results, using goal programming regarding all the goals, have shown that existing machines should be replaced by the LKT 81 skidder and the Vimek 610 forwarder to transport logs and firewoods, respectivlly. With the replacement, the costs of log transporting will increase to 15% and the costs of firewood transporting will decrease to 10%. Currently, the mechanization of wood transportation in Hyrcanian forests is not optimal in terms of quadratic goals and needs to be changed. In the forest machinery management, the environmental and ergonomic aspects should be taken into consideration.

One of the methods of using livestock exhaust is compressing and pelletting it, which causes facilitation of transportation, reduction of odor and gradual release of nitrogen. For manure pelleting, extruder and disk pelleting are used. Since the stones existing materials in the stored manure cause damage to the pelletting apparatus, so the removal of the stone from the manure before the processing is necessary. In this research, with the aim of separation the rock from the manure, a gravity separator was designed and fabricated. The performance of the device was evaluated by changing the three slope parameters of the material separator plates, manure moisture content and the size of the stone and manure dimensions The changed level was for 10, 15 and 20 ° slopes of separators, 10, 30 and 50% of the moisture content of manure, and for the particle size of less than 10, 10 to 20 and 20 to 50 mm. The maximum device separation efficiency of the stone from the manure was 76.81% at 10 ° slope, 50% moisture content and a particle size less than 10 mm.

Heavy crop residue on the soil surface impedes no-till drill performance and subsequent crop production in conservation tillage systems and therefore limit its adoption by farmers. Therefore, a field study was conducted to determine the effects of various residue management methods on no-till drill performance. The experimental design was a randomized complete block in five replications. The residue management systems were in four levels of leaving (T1), removing (T2), chopping (T3) and disking (T4). Factor analysis was used to group and identify the most effective indicators of drill performance. The results showed that various residue management methods had a significant effect on planting depth, the speed of emergence, effective field capacity, and depth uniformity. The minimum planting depth and depth uniformity observed for the T1 treatment in the corn crop. The findings revealed that the speed of emergence and depth uniformity was in the order T2>T3>T1>T4and T2>T3>T4>T1 in the corn crop. The results of factor analysis indicated that speed of emergence, planting depth and uniformity of depth were identified as the most effective indicators for evaluating no-till drill performance indexes.

Using bare-root seedlings for sugar beet farming has been given special attention due to recent droughts and introducing a mechanized system for production of seedlings in the nursery is important. To determine an appropriate sowing pattern, a split plot experiment based on the complete randomized blocks design was arranged to evaluate the effect of two seed distribution patterns including drilling and broadcasting (main plots) and applying of sand mulch or without sand (sub plots) on emergence indexes and number of applicable seedlings. To determine the most appropriate digging machine for the seedlings, four digging treatments including: undercutting with a blade digger, digging and sifting with a chain digger, undercutting and digging in two passes with the equipment of first two treatments and digging and picking by labour were compared in terms of quantitative losses and labour requirement in one of the subplots of the planting experiment. The results showed that broadcasting pattern along with applying sand mulch, having more uniform horizontal distribution compared to drilling and higher seed emergence than bare bed, can be introduce as the most appropriate system to host the required number of seedlings for an area equal to 10 times of the nursery. Evaluation of digging treatments revealed that employing the chain digger caused a high percentage of quantitative losses. Undercutting the seedlings by a blade digger, having lowest percentage of damaged seedlings and 30% cut in lobour forces compared to the manual digging, is recommended as the most applicable method among the available technologies.

The factors influencing the efficiency of tillage tools are such as soil moisture content, tool geometry and forward speed. This study was a spilit-spilit plot experimental design with three replications to determine the effect of new bent leg tillage on soil pulverization. Treatments were three soil moisture content levels of 7-10, 10-13 and 13-16 as the main plots, three forward speeds of 5, 7.5 and 10 km/h as the sub-plots and three blade spaces of 12, 16 and 20 cm as the sub-sub-plots. In this research, the effect of bent leg tillage on soil moisture content, forward speed and clod mean weight diameter (MWD) were studied. Results indicated that forward speed, shank spaces and soil moisture content during tillage affected MWD. Increasing forward speed and soil moisture content during tillage and also reducing blade spaces reduced MWD. The findings show that the technology of the new bent leg tillage has the potential to increase forward speed during tillage operation with reducing MWD. Also, it can improve work-rate and reduce the time of seed-bed preparation.

In this study, a software model was developed for the spreader unit of a centrifugal fertilizer and its spread performance was studied with different blade designs to recommend the best suitable blade for spreading of the pellet fertilizer. The blade designs include trapezoid, angled trapezoid, channel (U shape) and angle (L shape) that were compared with the control blade. In order to validate the software's results, a laboratory spreader device was fabricated based on a commercial centrifugal fertilizer machine. The spread pattern of the designed blades was investigated experimentally in a completely randomized design with three replications. The influence of blade design as the dependent variable, on Total Transverse Spreading Pattern (TTSP) and Coefficient of Variation (CV) as the dependent variables, was investigated to achieve the best design for blade in the experimental mode. Results showed that the trapezoid blade, among other blades, had the best spread performance with in the effective swath width during pellet spreading (CV=0.18). Other blades were ranked as angle blade (CV=0.29), channel blade (CV=0.38), angled trapezoid blade (CV= 0.57) and control blade (CV= 0.64) respectively. This ranking observed for both numerical software and the experimental results. Investigation on adaptation and compatibility between the software model and experimental results showed that, for all blades designs, there were acceptable agreements between software model and experimental (R2 ≥ 0.90).

Study on biometric parameters of trout species in the traditional method (based on human and non-automatic factors) are low-efficient due to serious problems such as disease transmission, stress-induced death, inaccuracy, & time-consuming. To overcome the problems of traditional method, an image-based vision system, including imaging and lighting chambers, was developed in this research. The fish biometric parameters were measured using fish movement videography during passage from the dark chamber. Then the selected images from the video were processed. The length, surface area, weight, amount of food consumed, & growth rate of trout were measured under fully controlled conditions and used as comparison criteria (control). Six mathematical models were used to estimate fish weight through measured parameters and among them the weight/length model was used as the best model for estimating fish weight. The accuracy of the system in estimating fish biometric parameters was above than 90% and the system’s capability to estimate the fish required food during the growth process was 98%.

In Iran, salinity is a pervasive issue limiting production of agriculture, so that a large part of the arid and semi-arid regions of the country have saline sodic soils with different levels. Saline soils and waters are among the agricultural resources that can be used for cultivation by using full recognition of problem and proper management. This study was performed to evaluate a special grain drill performance which plants wheat seeds into furrows for semi-arid regions with saline soils conditions in margin of Uremia Lake. The experimental treatments of planting method by the grain drill included, (i) planting into the furrows with 60 cm width and furrow irrigation; (ii) planting into the furrows with 100 cm width and furrow irrigation; and (iii) planting on a flat soil and flood irrigation. Statistical analysis was conducted based on randomized complete block design with three replications. Seed emergence rate, crop performance indices, water consumption, water productivity, and soil salinity distribution after each irrigation practice were measured. According to the results, there was no significant difference between the methods of planting in any of the measured parameters at the 5% probability level. Results also showed that reducing the width of the furrow from 100 to 60 cm caused salinity reduction (about 37 percent) from inside the furrows. The water productivity of the planting into the furrows with 60 cm width was about 40 percent higher than those of other treatments. Therefore, wheat planting method by the grain drill into the furrows with 60 cm width can be recommended in semi-arid regions with saline soils.

In dry clay soils, farmers irrigate the farm before tillage (pre-planting irrigation or PI) to reduce the soil resistance then tilling when the soil moisture sufficiently reduced for machine traffic. In this experiment, Five tillage-planting methods included direct drilling or seeding without PI (T1), tilling with disk harrow (one pass) before direct seeding without PI (T2), direct seeding at field capacity condition of soil after PI (T3), direct seeding  at high soil moisture condition after PI (T4), tilling with disk harrow (two passes), leveling, and seeding with traditional seeder(control T5) were compared in a randomized complete block design with three replications in terms of fuel consumption, operation time, plant number per square meter, number of weeds and grain yield of wheat. Results showed that T5and T4 with a grain yield of 5287 and 5168 kg/ha, were superior to other treatments. The highest number of weeds obtained in T3 with 42.34 m-2, while in T5, most of the weed controlled by disposing of the disk and decreased to 7.33 m-2. Finally, in the presence of enough water and time for PI T4 was better than T5 and recommended due to the lack of first irrigation and germination of wheat seeds with moisture in the soil, reduced fuel consumption from 34.11 to 11.35 lit/ha and reduce time required for tillage-planting operation from 2.91 to 0.40 h/ha compared to the control. Otherwise, T2 with grain yield of 4734 kg/ha is recommended, due to 30% reduction in fuel consumption and a reduction of 57% in time required than the control.

Tillage as a preliminary step for agricultural production consumes large amounts of energy. Regarding the energy crisis and the greenhouse gas emissions caused by the indiscriminate use of fossil fuels, many efforts have been done to reduce energy consumption as much as possible. The aim of this case study is to evaluate the effect of design and operational parameters of cultivators on the required tensile force and fuel consumption during tillage operation with a farm cultivator which had 8 shanks with specific blade geometry on a clay loam soil with specific moisture content. Experiments were carried out using response surface method and central composite design (CCD) by taking three levels of tractor forward speed (3, 5 and 7 km/h), three widths of the blade (5, 10 and 15 cm) and three tillage depth (6, 12 and 18 cm). Design Expert 8.0.6 software was used for experimental data analysis. The results showed that the blade width, forward speed and tillage depth had a significant effect on fuel consumption and tensile strength at %1 probability level. The relationship between the dependent and independent variables was presented as a second-order regression model and optimal values of independent variables were determined. The maximum desirability was determined at tillage depth of 18 cm, the forward speed of 7 km/h and a blade width of 5 cm.

Wheat as strategic product, has the highest area of cultivation and crop production in Iran. In this study energy use pattern for irrigated wheat production in Alborz province of Iran was studied and the score of technical and scale efficiency of producers were analyzed using a non-parametric data envelopment analysis (DEA) technique for discriminate efficient farmers from inefficient ones. The study also helped to identify the wasteful uses of energy by inefficient farmers and to suggest reasonable savings in energy uses from different inputs. Further, the effect of optimization of energy on energy ratio and energy productivity was investigated. Primary data were obtained through field survey and personal interviews using questionnaires from 20 randomly selected irrigated wheat farms from Alborz province, the one of important center of wheat production in Iran. Secondary data and energy equivalents were obtained from available literature using collected data of the production period of 2017–2018. The inputs were human labor, diesel, machinery, fertilizers and chemicals, water for irrigation, seeds and electrical energies; while the yield value of wheat was considered as output. The results revealed that, the total input energy, output energy, energy use efficiency, energy productivity, net energy were 45458.84 MJ.ha-1, 162169.28 MJ.ha-1, 3.57, 0.27 kg.MJ -1 and 116710.44 MJ.ha-1, respectively. It was disclosed that the greatest shares of input energy with 43.06% (19576.2 MJ.ha-1) corresponded to the fertilizers. The production of wheat in the province of Alborz is reasonable because of the positive amount of net energy index. About 20% of farmers were found to be technically efficient. Based on input-oriented CRS and VRS models of DEA, the average values of technical efficiency, pure technical efficiency and scale efficiency were found to be 0.893, 0.990 and 0.901, respectively. The results also suggested that, on average, about 3.51% (1610.62 MJ.ha-1) of the total input energy could be saved without reducing the wheat yield from its present level provided that all farmers operated efficiently by adopting the recommendations based on the present study.