نشریه تحقیقات سامانه ها و مکانیزاسیون کشاورزی
پیاپی 72 (بهار و تابستان 1398)

The weeds must be removed from the field due to their competition with principal crops to use water, nutrients, sunlight, etc. There are different methods to remove the weeds: mechanically, manually or chemically (applying herbicides). For farmers, applying herbicides is a usual way, but brings some concerns, from the point of environmental issues, due to equal application of chemicals all over fields, regardless the presence or absence of weed. For this reason, a machine vision system based on video processing was proposed to recognize Secale cereale L. (as a weed) from potato plant (as principal crop) to make herbicide application more accurate. Nine hundred sixty five objects were recognized after taking videos, pre-processing and segmentation. Fourteen features were extracted from each object. Using the hybrid artificial neural network-genetic algorithm, of 14 extracting features, only 6 features were selected as effective ones: average, the third moment, autocorrelation, correlation, dissimilarity, and entropy. Data were classified into two groups: training data (70% of the total data) and testing data (30% of the total data). The classification was performed using hybrid of artificial neural network - Bio-geography Based Optimization (BBO) algorithm. Performance of classification system was evaluated through analysis of confusion matrix and Receiver Operating Characteristic (ROC). Sensitivity, specificity, and accuracy were calculated using confusion matrix. The results showed that the sensitivity, accuracy and specificity of classification system reached to an acceptable level: 99.49 %, 99.65% and 98.91%, respectively. Our conclusion is that it is possible to manufacture the machine vision system with mentioned aims that work as online.

One of the most important issues in agricultural machinery section is tyre - soil interactions. In this study, a single wheel tester was used to follow experiments in controlled conditions in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tyre was operated at three vertical loads of 6, 9 and 12 kN, three inflation pressures of 80, 120 and 160 kPa and three moisture content of soil: 11.20, 14.86 and 18.68 % d.b to investigate the effect of the variables on these parameters: contact area, contact pressure, compaction, and soil apparent electrical conductivity. It was found that medium contact pressure had a direct relation with vertical load, inflation pressure and moisture content. A regression model with R-square of 0.946 was achieved to predict contact pressure. Soil electrical conductivity changes was predicted with acceptable determination coefficient of 0.850 by using of vertical load, inflation pressure and moisture content. Determination coefficient magnitude for models to predict resistance to soil penetration (cone index) using soil apparent electrical conductivity decreased when moisture content was increased. The vertical load and inflation pressure were found two factors controlling the soil apparent electrical conductivity changes in low and high moisture content, respectively. Error percentage in using soil apparent electrical conductivity parameter to estimate the penetration resistance increased with increasing moisture content.

Now day, global warming is too considerable due to consumption of fossil fuels. Use of fossil fuels in power plants for electricity generates has the largest portion of greenhouse gas and emissions in the world. Agricultural section has the outstanding contribution in electricity industry; furthermore the processing and drying of agricultural products have the highest consumption energy. In the current research, the parameters of energy, the environment (global warming) and social costs of drying of apples slices at three temperatures 45, 55 and 65° C and the air velocity 0.5 m/s for different pretreatment of osmotic, ultrasound, blanching and microwave (each pretreatment at three levels) were evaluated. Result shown that the amount of time, energy consumption, specific energy and heat consumption decreased with increasing temperature and using different pretreatments as compared to control treatment. Also, energy, drying and thermal efficiency, increased with increasing air temperature. The highest amounts of energy and drying efficiency were obtained %5.04 and %5.62, respectively for microwave pretreatment involving 360 W power and 2.5 min at 65° C temperature. Normal treatment with 45°C temperature gave the lowest value of efficiency energy (%2.27) and drying (%2.38). Results revealed that the highest and lowest greenhouse gas for the withdrawal one kilogram of water from apple slices was produced 21.19 and 9.37 kgCO2, 10.05×10-4 and 4.45×10-4 kgCH4, 2.01×10-4 and 0.89×10-4 kgNO2 respectively. Also, the highest and lowest social costs for  leaving one kg of water from apple slices was obtained 34927.60 and 15449.04 Rials for steam power plant, 35263.45 and 15597.59 Rials for power plant and 30561.66 and 13517.91 Rials for combined cycle power plant, respectively.

In mechanized harvesting, it is very important to develop an appropriate rice reaper for decreasing costs and crop losses. In this study, the field performance of two rice reapers (self-propelled and knapsack power reapers) were compared with manual harvesting. The experiment was conducted in split-plot design with the rice varieties as the main factor in two levels (Hashemi and Khazar) and the harvesting method as sub-factor in three levels (three harvesting methods) based on randomized complete block design in three replications. The results revealed that the effective field capacity of a self-propelled reaper (0.237 ha.h-1) and knapsack power reaper (0.048 ha.h-1) was significantly higher than that of the manual harvesting (0.0083 ha.h-1). The time required for harvesting one hectare using the self-propelled reaper, knapsack power reaper and manual method were 4.22, 20.74 and 119.71 h, respectively. The labor requirements in harvesting for manual method were 159.7 man-h.ha-1 and those of the self-propelled and knapsack power reapers were determined 52.22 and 68.74 man-h.ha-1, respectively. The harvesting losses when self-propelled reaper and knapsack power reaper are used and manual method is practiced,  registered as 2.42% and 2.58 and 2.18 %, respectively. The net saving cost using self-propelled and knapsack power reapers were 7940728 and 4444297 Rial.ha-1 as compared to that of manual harvesting. The break-even point for knapsack power and self-propelled reapers were determined 2.00 and 11.42 ha.year-1, respectively.

Sugarcane, a perennial plant, has been cultivated in Khuzestan province, Iran, for a long time. Sugarcane seeds and stems (whole stalk or billet), both, are used for propagation, but stems planting is primary method of cultivation for sugar production purposes. Costs of sugarcane planting in Khuzestan differ when different planting methods are practiced. This study was conducted to find out proper planting methods  for Khuzestan’s conditions. To achieve the aims, various parameters were checked, then influencing variables were determined; experiments were carried out  in Hakim  agro-industrial farms, in 2016 . The following topics were considered: costs indices, billet burial quality, factors affecting field capacity, numbers of tractor coming and going on the farms, and finally ergonomic issues. Indicators were summarized as much as possible by merging into each other or turning. Factors weighting were done, using expert discretions and AHP to indicate the importance of each indicator. Integration of relative weights by multiplying the relative weight of each indicator on the above parameters was carried out and also consistency index was calculated by ratio of incompatibility and random index. In next step, by selecting factors and AHP, three planting methods were compered using Expert Choice software: conventional manual method, semi-mechanized planting method (by cutter planter), and mechanized planting method (by automatic billet planter). Results showed that semi-mechanized planting method was optimal method due to  minimum costs and maximum quality achieved in billet burial practice. Manual planting, in spite of achieving optimal way of planting compared with mechanized planting, received low advantages because of increasing in planting expenses.

Khuzestan province produces 120,000 tones rice every year and possesses the forth rank in rice production in Iran. Paddy rice must be dried before milling. In some regions in Khuzestan, paddy is dried in traditional bed driers, resulting high costs and high losses from the point of quantity and quality. An indirect cabinet solar dryer with three trays and grooved collector was constructed to use solar energy, a project that could help farmers to increase their income and to reduce paddy losses. To measure and to record drying air temperature and humidity at different places (collector air incoming and outgoing and the drying chamber), a Digital Data Logger was designed, fabricated and mounted on the solar dryer. The dryer performance was evaluated by drying two paddy varieties (Shafagh and Anboori) in three levels of mass density of 1, 2, and 3 trays at two different solar dryer types of collectors: simple grooved collector (collector A) and grooved filled by turnery iron chaff collector (collector B). The results showed that maximum and minimum drying period required in different solar dryer treatments were 4 and 6.1 hours for Shafagh with 1 tray and for Anboori with 3 trays respectively. Longer time required for drying paddy rice in upper trays as the air flowing decreased due to increase in mass density. Mean time required for drying Shafagh variety was 12.8% shorter than that of Anboori variety. Increasing in number of trays in the solar dryer resulted in less rice losses. Results showed that utilizing solar energy, as a clean renewable energy source and appropriate method for reducing costs of  drying paddy rice, could be  recommended to use in Khuzestan province condition.

Different reasons can be listed to explain long delays in milling of the harvested sugarcane in sugarcane agroindustry units:  factory's downtime, failures of tractors in waiting line, accident due to crowd of tractors in yard, and shift change that creates quite long queues. To understand the dimensions of this problem, queuing theory was used in the basis of (1) to obtain a supply of sugarcane queuing system (2) to obtain a proper queuing system in the supply of sugarcane (3) to obtain a minimal cost to the queuing system in the supply of sugarcane. The research was carried out in an agroindustrial sugarcane in Khuzestan province. The required data related to arrival and service times of tractors were collected in 2016. Data analysis were performed according to the queuing models in the agroindustry unit. Based on preliminary observations, queuing system of agroindustry unit was a single channel model with one server, so this study was carried out by M/M/1 model. The results showed that average waiting time of queuing system with a single channel in servicing was 2 hours and 6 minutes, so in 60% of cases, the queue length will be longer than what servicing can respond. Calculations indicated that the costs could be minimized by increasing service levels up to 7.3%. The long queue in the queuing system can be improved by increasing service levels including: following preventive maintenance rather than corrective maintenance, using hidden factory, using spare parts, and expanding area for waiting line, accordingly

One of the objectives of precision agriculture is to minimize the volume of herbicide application by using weed management systems. To achieve  this goal, a system based on image processing techniques was developed to detect weeds. In the proposed method, HSV color space was used to discriminate between vegetation and background, and between crops and weeds. In this research, the H component of HSV color space along with suitable erosion and dilation were used to automatically segment background (soil) and foreground (weed). According to what was  obtained, the algorithm could identify weed from sugar beet plants with the accuracy of 94%. The intelligent sprayer system, in the field trials, in comparison with conventional sprayers (Buferagri sprayer), reduced 67.86% of volume of herbicide due to application of computer vision. The use of this method, as an intelligent sprayer system in sugar beet fields, is recommended.

In this study, energy consumption and pollutant emissions in producing local cookies in Guilan province have been assessed. Optimization techniques in energy consumption to reduce pollutant emissions were also shown using two conventional data envelopment analysis (DEA) and multi-objective genetic algorithm (MOGA). Required data, gathered from 30 units preparing local cookies, were used as the preliminary data for energy and environmental analyses. Also, the environmental impacts in cookie production were investigated using life cycle assessment (LCA) approach. Inputs and output were converted to equivalent energies based on equivalent energy values. Results showed that 30533.66 MJ of energy would be needed to produce one ton of cookies. The share of natural gas in providing energy to produce one ton of cookies was calculated as high as 16945.2893 MJ. Based on LCA results, the global warming (GW) index was calculated as 3732.09 kg CO2 eq. per ton of local cookies.Based on the results of DEA models, the optimum amount of energy consumption is 30221.5856 MJ ton-1, the energy saving percentage is 1.02 %, and the reduction of GW index is 190.3739 kg CO2 eq. per ton of cookies produced in the units. Following patterns proposed by MOGA would results  21.62% reduction in energy consumption, main part of which associated with cookies in which walnuts are  used. Based on the optimization results of MOGA, GW index per production of one ton of cookie was calculated as 2923.74 kg CO2 eq.

This study was conducted using a randomized complete block experimental design with five treatments and four replications in Marvdasht region, Fars province, for four years. Treatments included: 1) reduced tillage, 2) wheat and corn direct seeding, 3) corn direct seeding for four years, wheat direct seeding for the first two years and the fourth year, and conventional planting in the third year, 4) wheat direct seeding for four years, corn direct seeding for the first two years and the fourth year, and conventional planting in the third year, and 5) conventional tillage. Results showed that direct seeding and reduced tillage methods decreased fuel consumption, compared to the conventional tillage for 80% and 58%, respectively. Effective field capacity for seed bed preparation and planting increased in direct seeding and reduced tillage methods compared to the conventional tillage for 6 and 3 times, respectively. Conservation tillage methods also increased soil moisture retention (maximum of 32%) with respect to conventional tillage. However, there was no significant difference between tillage methods from the soil aggregates point of view; conservation tillage methods had more stable soil aggregates. For the first three years, wheat yield was significantly affected by the tillage methods (conventional tillage was practiced in most of these years); whereas, there was no significant difference between tillage methods for wheat yield in the fourth year of the study.

Semi-automatic tomato transplanter with conical distributing cups was designed, constructed and evaluated for mechanical transplanting of tomatoes seedlings. In this device, individual seedling was placed inside the cone bowls, by a mechanical distributer, and fell down into a previously plowed furrow via a tube. Cultivation accuracy variables including seedling spacing on the row, mechanical damages to seedlings, and seedling establishment angle, created with vertical line, were investigated. Tests used a factorial randomized complete block design with ten replications. The treatments included traveling speed (1, 2, and 3 kmh-1) and depth of roots established in the soil (5 and 10 cm). Results showed that the interactions between traveling speed and depth of cultivation did not affect the variables studied and the traveling speed factor was significant only at seedling establishment angle and mechanical damage to seedling; this factor had no significant effects on spacing. Also, cultivation depth was effective only at the deployment angle. Results indicated that the most appropriate traveling speed and depth of planting were 2 kmh-1 and 5 cm respectively. The capacity of the machine in this traveling speed, in single-row, was found 0.08 hah-1, theoretically.

The area under cultivation of watermelon in Iran is 1.2 percent of total area of agricultural land or 42.3 percent of the total area under cultivation of different species of cucurbits in this country. Unfortunately, the share of mechanical devices in watermelon cultivation, particularly in harvesting period, is low. Harvesting of watermelon, especially in loading stage, is extremely costly and time-consuming because of absence of appropriate machines. Based on what have been derived from questionnaire completed by some farmers of Fars province, of total manpower required to harvest watermelon, 70% goes for loading of this product. The aim of this study is designing and testing the deployment of the watermelon harvesting machine to improve harvesting efficiency. Farm experiments were carried out with different ways of machine working, including: harvesting and loading watermelon at the same time, loading pre-harvested products, different belt speeds (0.25, 0.4 and 0.55  m/s), and different number of labors for loading (putting harvested watermelon on conveyor belt) and for unloading (receiving watermelon from moving belt to fill up trailer). Loading capacity and losses of products (during loading and unloading) were also calculated. The highest rate of loading capacity (13.2 tons per hour) was in loading pre-harvested products with 7 labors and belt speed of 0.55 m/s. The highest losses (0.38%) was also in this case. The lowest rate of farm capacity (6.15 tons per hour) has been found when harvesting and loading of watermelon were done at the same time (three labors, 0.25 m/s belt speed). No losses could be found when 5 or 7 labors were involved in harvesting and loading and speed of belt limited to 0.25 and 0.4 m/s. Results indicated that combination of 7 labors and the speed of belt equal to 0.4 m/s was the best way of harvesting the products in terms of maximum field capacity and minimum losses. In this method, the manpower needed to pick up and to load one ton of watermelon reduced to 0.61 labor-hr. compared with 1.14 labor-hr.  in traditional way of harvesting.