نشریه تحقیقات سامانه ها و مکانیزاسیون کشاورزی
پیاپی 75 (پاییز 1399)

One way to reduce soil compaction is to add organic matter and to manage the field traffic. In this research, farmyard manure was incorporated into clay soil with rates of 0, 45, 60, 90 ton ha-1. After 6 months (September to March), at different numbers of tyre passes of 1, 6, 11 and 16, and three soil moisture contents of 8%, 11% and 14% soil compaction was evaluated measuring soil bulk density and soil sinkage. Experiments were conducted in the soil bin at the Urmia University under a single trector’s tire 220/65 R 21l under a constant load of 4 kN, inflation pressure of 110 kPa and at a forward velocity of 2.88 km hr-1. It was found that at manure rate of of 90 ton ha-1, comparing to no-manure treatment, soil bulk density and soil sinkage decreased by 14.7 and 6.94 percent, respectively. Also, increasing the number of tyre passes from 1 to 16 and increasing soil moisture content from 8 to 14 percent, increased soil bulk density 7.21% and 7.92%, respectively. For neural network modeling multilayer perceptron network with six neurons in the hidden layer with sigmoid transfer function and linear transfer function for the output neuron was used. Comparison of neural network output and experimental results showed high correletion with correlation coefficient of R= 0.99 between them. The mean square error (MSE) of the model and mean absolute percentage error of the system (MAPE) were 0.0119071 and 0.0009641,respectivly, which showed high accuracy of neural network to model soil compaction.

Today, one of the main challenges is to control fuel consumption, which has an effective role on other sectors of the economy. In this situation, efficient practices are necessary to reduce fuel consumption leading to lower costs. This paper shows how an intelligent control system has been designed and how an electronic engine speed control system was replaced with the mechanical system. The aim of construction and evaluation of an electronic system was to control engine speed in harvesting machines. The conventional control of engine speed in 7000 series sugarcane harvesters is mechanical. Stepper motor, drivers, micro-controller, joystick and potentiometer were used, as well as the C programming in code-vision to program the microcontrollers. A t test was conducted to compare fuel consumption between the systems. The statistical analysis showed significant difference between the control systems in 1% probability level. Results from the implementation of this system represented the design and proper functioning of the system. The results showed a reduction of about 6.3% in fuel consumption when electronic control system was used, comparing to mechanical control and this was due to the use of intelligent and automatically control of engine speed. Installation of this system on existing sugarcane harvesters will save about 505,000 liters of fuel annually.

In order to find how different types of weeders (powered and non-powered) are working in controlling weeds of peddy lands in which two rice cultivars, Deilamani and Hassansaraei, were grown, a field experiment was conducted in 2017-2018. This study was performed as a factorial experiment with cultivar in two levels, Deilamani and Hassansaraei, and weeding method in five levels including manual motor weeding, using single-row, two-row, three-row weeders, and control. The experiment was performed in a randomized complete block design with three replications. Evaluation parameters in this study included field capacity, field efficiency, weeding efficiency, weed charateristics, plant growth charateristics and the rate of damaged plants. The results showed that the highest (91.91%) and lowest (91.33%) efficiency were obtained when single-row powered weeder and three-row powered weeder, reaspectively, were used. In terms of field capacity, the single-row powered weeder was on the top of the list with 0.198 ha.h-1, and the non-powered manual weeder was at the bottom of the list with 0.0096 ha.h-1. In terms of field efficiency, the single-row powered weeder was on the top of the list with 78.22%, and the non-powered manual weeder was at the bottom of the list with 65.53%. The results obtained from this study indicated that the single-row powered weeder was recognized as the best weeder in controlling the rice weeds where Deilamani and Hassansaraei cultivars are growing.

Bread waste is the common part of food biomass in the world. The aim of this study was to investigate the effects of saccharification time and also substrate concentration on the amount of glucose as well as bioethanol obtained from bread wastes folowing hydrolysis processing. The bread wastes were crushed to small parts and then mixed with water at ratio of 10-15 (w/v%). Alpha-amylase and glucoamylase enzymes were used for liquefaction and saccharification, respectively. The effects of saccharification time and substrate loading parameters on the amount of glucose were investigated by using response surface methodology (central composite design) with Design Expert software. The glucose-derived from hydrolysis processing was measured by glucose kit. Aflatoxin contents of the bread wastes (as control sample) and optimum sample obtained from the hydrolysis processing (sample with the maximum glucose) were measured. Fermentation processing was carried out by using Saccharomyces cerevisiae yeast. The results showed that the highest amount of glucose (100.21 g/l) in enzymatic hydrolysis was obtained at the saccharification time of 48 h and substrate loading of 150 g/l. The hydrolysis processing at the higher concentrations and longer duration, due to high viscosity and adhesion, reduced the concentration of glucose, so high concentration did not have any favorable effect on the hydrolysis processing. The hydrolysis processing reduced Aflatoxin B1 and B2 at a ratio of 76% and 16%, respectively. The greatest amount of bio-ethanol in the fermentation phase (45.35 g/l) was obtained at 36 hours with efficiency of 88.7%. It could be related to the consumption of glucose produced in the hydrolysis phase due to proper growth of the cell mass during fermentation phase in this duration. The recommended time for the fermentation processing is 36 hours.

The furrow opener type and press wheel configuration in no-till seeders can have a major effect on crop emergence in conservation tillage systems. This is particularly important in southern regions of Fars province where in annual double-cropping systems (winter wheat and summer maize) a large volumes of maize residue remain on the soil surface. A field study was conducted to determine the effects of furrow opener type and press wheel configuration on sowing performance and subsequent wheat yield in rotation with corn. The experimental design was a randomized complete block in four replications. The treatments consisted of four different configurations for no-till seeder: no-till seeder with tine opener without press wheel (Notill.1), no-till with tine opener and press wheel (Notill.2), no-till with disk opener without press wheel (Notill.3), no-till with disk opener and press wheel (Notill.4), and conventional planter with shoe opener, and press wheel (Con.Drill). The results showed that furrow opener type and press wheel configuration had a significant effect on planting depth, speed of emergence, depth uniformity and crop yield. The Notill.1 and Notill.2 treatments increased sowing depth by 36.4% compared to Notill.4 and Notill.3 treatments. The highest depth uniformity was observed in Notill.3 and then in Notill.4 treatments,. The findings revealed that upon removing the press wheel from the seeding unit, higher speed in emergence was found in both the disk and tine opener treatments (Notill.1, Notill.3), compared to press wheel treatments (Notill.2, Notill.4). A comparison of mean values wheat yield showed that when the press wheel was not used, the Notill.1 and Notill.3 treatments caused increasing in  crop yield by 11.7% and 14.2%  as compared to Notill.2 and Notill.4 treatments, respectively.

In this research, the carrot was first grounded in equal pieces; the pieces underwent pretreatment using Ohmic and blanching methods. The treatments were preheated at 3 ohmic voltage levels as 40, 60 and 80 Volt and 3 period levels of 2, 4 and 6 minutes. Then parameters examined in the pretreatment blanching in 3 period levels of 2, 4 and 6 minutes. After the pre-treatment, samples were dried in microwave in 3 power levels of 360, 600 and 900 W. The qualitative properties of samples including antioxidant, flavonoids and total phenol content were determined for pre-treated and dried samples. A multilayer neural network of perceptron was used to teach data using 3 and 6 neurons in the hidden layer and three functions of hyperbolic, sigmoid, and linear tangent activation. According to the results obtained from the network, for Ohmic premixing method the best values of R2 and RMSE were observed for antioxidant content (sigmoid-6 neuron), flavonoids content (hyperbolic tangent-6 neuron) and total phenol content (sigmoid-6 neuron). Also, the activation network with 3 neurons in the hidden layer and the hyperbolic tangent activation function were able to obtain the best values of R2 and RMSE for the total phenol content, flavonoids and antioxidants in the blanching pre-treatment.

Weed control by mechanical means can reduce environmental concerns resulting from herbicides application, and also it can help reducing the costs of chemicals and application expenditures. This study was devoted to investigate the suitability of bent leg cultivator for eradication of weeds in sugar beet fields. Field study having seven treatments; bent leg cultivator with 45 mm width, bent leg cultivator with 45 mm width + furrower, bent leg cultivator with 65 mm width, bent leg cultivator with 65 mm width + furrower, conventional cultivator (crescent blade), control of weed in all seasons, and no-weed control were carried out as a complete randomized design in three replications. Field data were used to calculate weed control percentage, sugar beet root yield, sugar content and gross sugar yield. Analysis of data indicated that cultivator geometry affected both percentage of weed control and crop yield. The bent leg cultivator with 65 mm width + furrower, compared to conventional cultivator, increased weed controling (17.0%), root yield (5.5%), sugar content (0.6%), and gross sugar yield (6.1%). Findings showed potential of the new bent leg cultivator in increasing crop yield and decreasing herbicides application.