The relationship between machine and soil
J. Taghinazhad; S. Rahmani
Abstract
IntroductionThe harvesting stage is the most crucial phase in peanut production. In other words, one of the critical stages in producing this product is the harvest stage. Although it has its difficulties, this stage is associated with significant losses, which experts attribute to the high economic ...
Read More
IntroductionThe harvesting stage is the most crucial phase in peanut production. In other words, one of the critical stages in producing this product is the harvest stage. Although it has its difficulties, this stage is associated with significant losses, which experts attribute to the high economic value of peanuts. In recent years, farmers in the Moghan Plain have also started considering this product due to the special conditions of the Iranian economy. In 2020, this study investigated three methods of peanut harvesting in two stages: manual, tractor-mounted thresher (semi-mechanized), and harvesting with a pull-type combine. The first stage involves the complete removal of the plants from the soil, while the second stage involves drying and separating the peanut pod from the plant in Moghan.Methods and MaterialsThe experiment followed a split-plot design in the form of randomized complete blocks with four replications. The main plot consisted of soil moisture levels at harvest time, which were tested at three different levels: a1- 21%, a2- 18%, and a3- 15%. The sub-plot involved testing the separation of peanut pods from the plant using three different methods: b1- combine harvesting, b2- harvesting with a tractor-mounted thresher, and b3- manual harvesting. The study evaluated important harvest indicators such as quantitative loss (first and second-stage losses), actual field capacity, harvest time, and the number of required laborers. The results led to the identification of the best harvesting system.Results and DiscussionThe study revealed that the optimal soil moisture content for the initial stage of harvest was 18%. For most parameters, there was a significant difference observed among treatments at the 1% level. The pull-type combine method had the highest farm capacity with a maximum of 0.46 ha per hour, while the manual harvesting method had the lowest capacity with a minimum of 0.006 ha per hour. The total losses ranged between 5.95% and 10.58%, with the manual harvesting method exhibiting the lowest loss and the pull-type combine method showing the highest loss. Furthermore, the manual harvesting method required more labor compared to the other methods.ConclusionBased on the obtained results, it is recommended to use a pull-type combine for the early harvesting of peanuts and a manual method for obtaining high-quality peanuts in the Moghan region.
E. Chavoshgoli; Sh. Abdollahpour; H. R. Ghasemzadeh
Abstract
IntroductionThe nut sunflower is usually cultivated in small farms and is harvested with a low capacity of harvester at high moisture content. For the rigid threshing components, impact and knead force are so large as it leads to crushing of the grain or inner stress. This reduces marketability and the ...
Read More
IntroductionThe nut sunflower is usually cultivated in small farms and is harvested with a low capacity of harvester at high moisture content. For the rigid threshing components, impact and knead force are so large as it leads to crushing of the grain or inner stress. This reduces marketability and the germination rate of seeds. The mechanical damage degree of sunflower grain is influenced by the material of the threshing beaters, the velocity of impact, moisture contents, etc. Traditional manual methods, that separate grain from the sunflower head, take a lot of time, require large manpower, have high grain damage, and low efficiency. The objective of the present work was to develop and optimize a threshing unit for nutty sunflower that would combine safe impact velocities with appropriate adjusting of its variable to maximize threshing efficiency whilst minimizing grain damage resulting from shearing, cracking, or crushing.Materials and MethodsThe nutty Sunflower heads were procured from the Experimental Orchard of University of Tabriz, Iran at the moisture content of harvesting. Axial threshing units using kinematic equation and properties of the grain, designed and constructed that the variables of its components are adjustable. The beater of the thresher is flexible, which the deformation and vibration undergoing the overall rotation and impact process becomes larger with increasing speed and prevents grain damage. The power required for threshing and separation grain from heads was calculated at about 4.5 kW. Diameter and rotational drum speed value estimated using relation (V= and study of other researches as considering critical impact velocity of sunflower grain. The length of the thresher was 1.2 m that estimated by determining the capacity and the number of beaters. Threshing efficiency (%), separation efficiency (%), and grain damage (%) were parameters of performance for study. The experimental design by the Response Surface Methodology in Design Expert software 11 with central composite experiment design developed and the affecting parameters on accuracy analyzed and optimized. The threshing unit was evaluated against three threshing drum speeds of 380, 280, and 180 (rpm), feed rates 4000, 3000, and 2000 (kg (head)h-1), moisture content of 60%, 45%, and 30 (%w.b).Results and DiscussionThe results showed that the models and effect of variables were statistically significant at the 95% confidence level. The moisture content on threshing efficiency and grain damage had the greatest effect followed by drum speed and feed rate. While for separation efficiency, the feed rate had the most influence. With reducing feed rate and moisture content the threshing efficiency increased, although the decrease in drum speed reduced it. This might be due to sunflower grains adhering loosely to the head at the low moisture contents. The maximum (99.81) and minimum (96.12) percentage of threshed heads was at the moisture content of 30 and 60, respectively. The separation efficiency increased with reducing of feed rate and moisture content. Though, drum speed had insignificant efficacy statistically. The sunflower heads with high moisture content are fragile and brittle, also at high feed rates, the number of impact forces and collisions of heads rises in the condition of threshing. Therefore, the extra MOG is produced and passed from the separator grille. The feed rate of 2000 kg h-1 and moisture content of 30% was the maximum point of separation efficiency that obtained 69.82%. The grain damage decreased significantly with reducing drum speed (380 to 180) and moisture content (60 to 30). This result may be due to the reasons that at higher moisture content the husk of grains becomes soft. The goal of optimization is maximizing threshing and separation efficiency and minimizing grain damage that the optimized values of variables were determined 292.134 rpm for drum speed, 2000 kg h-1 for feed rate, and 30.7406% (w.b) for moisture content.Conclusion A threshing unit of sunflower, using properties of grains and kinematic equation, was designed and constructed. The models and effect of the variable were statistically significant on performances. The moisture content had a greater effect than other factors on threshing efficiency (%) and grain damage (%). Also, the feed rate of crops in thresher had the most influence on separation efficiency (%). With decreasing the moisture content, threshing and separation efficiency increased and grain damage reduced. The threshing efficiency (%), separation efficiency (%), and grain damage (%) were reported in the range of 96.12 to 99.81, 57.34 to 68.55, and 0.49 to 1.25, respectively. The optimized points were determined at the drum speed of 292.134 m s-1, feed rate of 2000 kg h-1, and moisture content of 30.7406% (w.b).
S. Ahmadipour; M. H. Aghkhani; J. Zareei
Abstract
Introduction Today, maximizing the efficiency of fuels and increasing the output power of diesel engines is considered inevitable due to the increasing need for energy resources, the reduction of fossil fuel resources, the need to maintain the environment, reduce air pollution, and limit the electricity ...
Read More
Introduction Today, maximizing the efficiency of fuels and increasing the output power of diesel engines is considered inevitable due to the increasing need for energy resources, the reduction of fossil fuel resources, the need to maintain the environment, reduce air pollution, and limit the electricity supply and fuel supply. In the large cities of Iran, the problem of vehicle pollution is one of the main problems. The lack of proper fuel, soot filters, and absence of requirement for a technical inspection of diesel vehicles have led to an increase in mortality and the growth of lung cancer due to pollution. All of studies indicate that fossil fuels, despite the low cost of production, will increase the cost of both living and environment. A solution for this crisis is to reduce the sources of pollutant-producing sources from the source of these pollutants. In the internal combustion engines, the compression ratio and alternative fuels are two important factors affecting engine performance and exhaust emission. Materials and Methods In this research, a one-dimensional computational fluid dynamics solution with GT-Power software was used to simulate a six-cylinder diesel engine to study the performance and exhaust emissions with different compression ratios and alternative fuels. The compression ratio was chosen to be 15:1 to 19:1 with an interval at unity. Alternative fuels such as (as base diesel), methanol, ethanol, diesel and ethanol, biodiesel and decane were selected. To modeling engine, first, all parts of the engine were introduced as a real six-cylinder engine, and then the required data were entered according to the actual engine conditions at the atmospheric pressure of one atmosphere. Before this investigation was carried out, a validation model for evaluation was done by experimental and simulation data. The validation results showed that software model error is acceptable and the model has a good capability of fitting and predicting. Results and Discussion The engine performance was evaluated in terms of engine power, engine torque, and specific fuel consumption at different engine compression ratio and fuel. The results showed that with increasing the compression ratio, brake power and brake torque increased. Among the fuels used in this engine, the maximum brake power and brake torque in the compression ratio of 19 with the decane fuel were 3.86% higher than that the base fuel and the lowest value was awarded in the compression ratio of 15, with methanol fuel and it was equal with 56.04%. The results indicated that by increasing compression ratio, the brake specific fuel consumption was reduced due to more power than the fuel consumed in the engine. A fuel with lower heating value should be injected more mass to the engine. This will increase the brake specific fuel consumption. In this research, the decane fuel with a compression ratio of 19 with a reduction of 3.72% had the lowest brake specific fuel consumption among other fuels. The CO emission from the engine largely depended on the fuel's properties, the availability of oxygen, the fuel mix with air, temperature, and turbulence inside the combustion chamber. The results highlighted that by increasing compression ratio, CO emission increased and CO emission in biodiesel fuel, with a compression ratio of 15, was decreased by 82.37% compared to the base. CO2 emissions are not too harmful to humans, but they increase the potential for ozone depletion and global warming. With increasing compression ratio, CO2 and HC emissions increased for all fuels, CO2 emissions have risen up the base. The fuel heating mechanism, combustion temperature, oxygen content, and gas fuel availability are the most important factors in the formation of NOx. With increasing the compression ratio, the amount of NOX increases, which is due to the high temperature in the cylinder at a higher compression ratio. The viscosity and density of fuels have an effect on NOX emission, and because of the larger droplets of the fuel, it released NOX. The highest NOx emissions from biodiesel fuel are due to the high oxygen content of this fuel and the lowest NOx emissions from decane fuel, due to the low density of the fuel compared to other fuels. Conclusion The results of this study showed that the decane fuel with a compression ratio of 19 in total had the best functional and pollutant characteristics among the six fuel used in this study. Therefore, this fuel can be the best alternative for diesel fuel.
I. Eskandari; V. Feiziasl
Abstract
Introduction Winter wheat is an important, well-adapted grain crop under dryland condition of the northwest of Iran. Soil water is the most limiting resource for crop growth in dryland areas. Therefore, farmers need to use crop residues and minimum tillage to control the soil erosion and effectively ...
Read More
Introduction Winter wheat is an important, well-adapted grain crop under dryland condition of the northwest of Iran. Soil water is the most limiting resource for crop growth in dryland areas. Therefore, farmers need to use crop residues and minimum tillage to control the soil erosion and effectively store and to use the limited precipitation received for crop production. Crop rotation and tillage system could affect crop yield due to their effects on water conservation and soil chemical and physical properties. Galantini et al., (2000) studied the effect of crop rotation on wheat productivity in the Pampean semi-arid region of Argentina and found that a wheat–vetch (Vicia sativa L.) rotation resulted in higher yield and protein content, and greater yield components than the other rotations.Payne et al. (2000) stated that where precipitation amount is marginal (400 mm), dry field pea offers a potential alternative to summer fallowing. The purpose of this study was to identify the optimal tillage system for increasing crop productivity in a vetch–wheat rotation in dryland farming of the northwest of Iran. Materials and Methods The field experiment was carried out from 2010 to 2014 at the Dryland Agricultural Research Station (latitude37° 12´N; longitude 46◦20´E; 1730 m a.s.l.), 25 km east of Maragheh, East Azerbaijan Province, Iran. The long-term (10 years) average precipitation, temperature and relative humidity of the station are 336.5 mm, 9.4 ◦C and 47.5%, respectively. The soil (Fine Mixed, Mesic, Vertic Calcixerepts, USDA system; Calcisols, FAO system) at the study site had a clay loam texture in the 0–15 cm surface layer and a clay texture in the 15–80 cm depth. This study was conducted in vetch (Vicia pannonica)- wheat (Triticum aestivum L.) rotation. The experiment was arranged in a randomized complete block design with four replications. The tillage treatments consisted of (1) conventional tillage: moldboard plowing followed by one pass of a disk harrow (CT); (2) reduced tillage:chisel packer (CH); (3) minimum tillage: Stubble mulch cultivator (MT); and (4) no-till (NT) with retained previous crop residue. At beginning prior to the tillage operation, only wheat stubble was present on the soil surface. A uniform tillage treatment was applied to all plots using a chisel packer in October. A shallow tillage was also performed using a tandem disk harrow just prior to winter vetch planting. In the second, third, fourth and fifth years, the tillage treatments for the vetch and wheat planting were similar. A winter wheat cultivar (Azar 2) was sown 6 cm depth at a rate of 350 seeds per square meter with an Alvand conventional and Baldan NT 250 no-till drill. Vetch cultivar Golsefied was drilled 8 cm depth at a seeding rate of 85 kg ha−1 using Alvand drill. The following parameters were measured: heads of wheat per square meter, 1000-kernel weight, kernels per head, head length, plant height, and wheat grain yield. Grain yield was obtained with a plot combine harvester. The dry matter content was determined and yield corrected to a standard moisture content of 130 g kg−1. Rain use efficiency (RUE) was calculated by dividing dry weight of grain yield by growing season precipitation. Soil water content and dry bulk density were measured gravimetrically (drying method, w/w) in cropping seasons. Results and Discussion Conservation tillage treatments resulted in water saving in soil layers. In both stages of soil sampling, the most soil moisture variability to initial state was observed in plots which planted as no-tillage. The moisture variability of no-tillage system was 23.4% higher than that of conventional tillage system at 10-20 cm soil layer in flowering stage of wheat. Effect of treatments on soil bulk density in different soil depths illustrated that conservation tillage can reduce soil bulk density during four years. According to the results of this study the overall infiltration in no-tillage was 1.58 times more than that of conventional tillage system. Yields under no-tillage and reduced tillage were higher (4% and 6% respectively) than conventional tillage. Grain yields under direct drilling were similar to those obtained using the reduced-tillage (Chisel packer) system. Conclusion Based on the results of a 4-year field study on a dryland production system in the northwestern cold continental climate of Iran, minimum- or no-till winter wheat crop production in a vetch–wheat rotation were the most efficient soil management practice from the standpoint of grain yield production and rain use efficiency. Overall, in this study, the no-tillage treatment is proposed as the best treatment in terms of grain and biomass yields and mechanical properties of soil.
J. Taghinazhad
Abstract
Introduction One of the most important agricultural crops is rape seed oil as its special features can play an important role in the agricultural region. Due to the presence of more than 40% oil and 25% protein in the grain can play an important role in the supply of edible oil. After determining of ...
Read More
Introduction One of the most important agricultural crops is rape seed oil as its special features can play an important role in the agricultural region. Due to the presence of more than 40% oil and 25% protein in the grain can play an important role in the supply of edible oil. After determining of various factors such as uniformity of planting depth, evenness between shrub, plant height and grain yield concluded that Nordsten drill along the seeding density of 75 cm for mechanized planting is acceptable yield. Afzali nia et al. (1999) in one study aimed to assess the performance of common grain drills in Iran in Zarghan area in Fars Province showed that differences between treatments in terms of seed distribution uniformity factor, plant population per unit area and yield product is not significant. The purpose of this study was to evaluate and select the most suitable types of canola planter and variable seed rate planting density and aims to increase the canola cultivated area by the highest yield. Materials and Methods Moghan Plain, located in the north areas of Ardebil province, is considered as an important areas of canola planting in Iran. This study was performed in the agricultural research center of Ardabil Province (Moghan) (39°39´N; 48°88´E; 78 m a.s.l.) in Northwest of Iran. To evaluate different planters with varied seed rates on canola yield. The experimental design was carried out in a randomized complete block design with strip splits (varied seed rates 6, 8 and10 kg per hectare and different drills consist of B1: Barzagar Hamadani drill (conventional method) B2: Amazon drill pals teeth harrow, B3: Gaspardo drill pals teeth harrow and B4: Agromaster drill) and four replications. To investigatethe different treatments in the experiment, various parameters such as percent germination, seeding uniformity of width and depth intervals, plant establishment, effective field capacity, fuel consumption rate andgrain yield were measured. Results and Discussion The evaluation of results of drill types showed that there was significant difference between the planters type and other performance parameters. Different planters with varied seed rates also had significant effects on germination at 1% probability level and B4 had maximum percentage of seed germination (89.45%). Uniformity of seed distribution was found to be the highest for B4 in vertical distribution uniformity (72.62%) and inter-row uniformity (84.25%). The analysis of variance for two years showed that the grain yield and establishment of seed were significantly affected by year. Result of variance analysis for yield indicated that there was a significant difference between planting machines in 1% of probability level. Therefore, maximum yield in this experiment related to B4 with 2672 kg ha-1. The results of technical and economic comp ration indicate that the added net income of B4, was 4940 thousand Rails per hectare compared to the conventional method. Conclusion Results showed that the average of yield of the first year was significantly greater than that of the second year. Results indicated that use of B4 lead to the highest of yield 2672 kg ha-1. But in terms of plant height no significance was found. The results of technical and economic comp ration comparison indicated that the added net income from B4, was 4940 thousand Rails per hectare compared to the conventional method. Therefore, considering many factors, the Agromaster drill tested in this study was found to be the best suited planter and therefore is recommended for canola planting in the region.
M. Torkian Boldaji; A. M. Borghaee; B. Beheshti; S. E. Hosseini
Abstract
Introduction Thermal processing has a huge impact on the textural attribute of the final food product and texture is a major factor contributing the overall quality of food. Ohmic heating is an advanced thermal processing method in which heat is internally generated within foods by passing an alternating ...
Read More
Introduction Thermal processing has a huge impact on the textural attribute of the final food product and texture is a major factor contributing the overall quality of food. Ohmic heating is an advanced thermal processing method in which heat is internally generated within foods by passing an alternating electric current through them. Ohmic heating can volumetrically heat the entire mass of a food system, resulting in faster heating, better quality and less energy consumption than conventional thermal processing. Gradient voltage and electrode type have high effect on ohmic heating system. Materials and Methods In this study, the effect of voltage gradient and electrode type on moisture reduction time, a/b, ΔE color indexes and energy consumption were studied. For this purpose, four levels of voltage gradients (5, 7, 9 and 11 V cm-1) and four electrode types (Aluminum, Stainless steel, Brass and Graphite) was investigated by ohmic heating in tomato paste processing. Tomato used in this study was purchased from a local market. The whole tomatoes were washed, crushed and mixed in a way that a red less-viscous liquid obtained (Fig. 1). This liquid was considered as tomato samples in the remainder of the article. Ohmic cooking experiments were conducted in laboratory scale ohmic heating system consists of a power supply, a variable transformer, power analyzer, a microcomputer, digital scale (GF-6000) and thermometer (Dual inpur RTD 804U) (Fig. 3). The ohmic cell had a PTF cylinder with an inner diameter of 0.05 m, a length of 0.10 m and two electrodes on both side of the cell. A hole with 3 mm diameter to insert the thermocouple was created and two holes with 5 mm diameter was created on surface of cell. One of them was used for pouring tomato puree and other for exiting steam from cell. Temperature uniformity was checked during previous heating experiments by measuring the temperatures at different locations in the test cell. Ohmic heating was accomplished till the moisture content of the tomato samples reduced from initial moisture content of as 91(wet basis) to a safer level of 70 (wet basis). Moisture reduction time, a/b and ΔE color indexes, temperature and energy consumption were measured. Results and Discussion The results of the nonlinear mathematical model showed that the effect of different voltage gradient levels on moisture reduction time, ΔE parameters and energy consumption had a good agreement (α≤0.01) as well as voltage gradient had a significant effect on a/b color index (α≤0.05). Electrode type had significant effect on processing time, ΔE (α≤0.01), on energy consumption and a/b index (α≤0.05). Interaction of voltage gradient and electrode type was significant on processing time, energy consumption, a/b and ΔE (α≤0.05). In all electrodes by increasing the voltage gradient, processing time and energy consumption were reduced. For example by increasing the voltage gradient from 5 to 11 V cm-1, processing time and energy consumption were decreased on average 38% and 23%, respectively. Minimal processing time and minimal energy consumption were observed in 11 V cm-1 with graphite electrode that were 17 min and 203 kJ, respectively. As well as maximum processing time and maximum energy consumption were obtained in 5V cm-1 with aluminum electrode that were 105.21 min and 321 kJ, respectively. But maximum a/b parameter and minimal ΔE index were observed with stainless steel electrode in 11V cm-1. In determining the best electrode, in addition to the processing time and energy consumption, product quality is also an important parameter. However, graphite electrode has better performance in terms of time and energy consumption, but stainless steel electrode has better performance in term of product quality. Since the production of food, quality is an important parameter, and also the two electrodes graphite and steel are similar in terms of energy consumption and processing time, but stainless steel electrode is better in term of quality, so stainless steel electrode is selected for ohmic heating tomato paste. Conclusion Different voltage gradients and Electrode type have a significant effect on processing time, energy consumption, ΔE and a/b color indexes. Minimal processing time and minimal energy consumption were observed in 11 V cm-1 with graphite electrode that were 17 min and 203 kJ, respectively. But maximum a/b parameter and minimal ΔE index were observed with stainless steel electrode in 11V cm-1. Stainless steel electrode and 11 V cm-1 voltage gradient were the best condition for tomato paste processing by ohmic heating.
K. Abbasi; M. Almassi; A. M. Borghaee; S. Minaei
Abstract
Agricultural mechanization is a method for transiting from traditional agriculture towards industrial and sustainable one. Due to the limitation of natural resources and increasing population we need to have economical production of agricultural crops. For reaching this destination; agricultural mechanization ...
Read More
Agricultural mechanization is a method for transiting from traditional agriculture towards industrial and sustainable one. Due to the limitation of natural resources and increasing population we need to have economical production of agricultural crops. For reaching this destination; agricultural mechanization has a remarkable role. So it is necessary to have an extensive view for mechanization, because with the help of mechanization the agricultural inputs such as seeds, fertilizer and even water and soil can effectively be managed for an economical and sustainable production. This study has been carried out in many provinces of Iran. The data of agricultural tractors and cereal combine harvesters were firstly gathered by means of questionnaire. The tractors were categorized in four power levels of less than 45, 45 to 80, 80 to 110, and more than 110 hp. In addition, it was also carried out for cereal combine harvesters; it was in three power levels, i.e. between 100 to 110, 110 to 155 and 155 to 210 horse-power in 3 ages, i.e. less than 13, between 13 to 20, and more than 20 years. Information regarding to cultivation areas, production volume, and yield of main crops gathered from statistics of Ministry of Jihad-e-Agriculture. Then agriculture mechanization level index (hp ha-1) in each province was calculated. Four main crops including irrigated and rain-fed wheat and irrigated and rain-fed barley, which met the required criteria to be used in the model, were statistically analyzed. Correlation analysis was carried out in order to get an effective model between yield of the four main crops in Iran and agriculture mechanization level index. Pearson correlation index showed that there is a direct and significant correlation between these variables. Subsequently, outliers were identified in order to get a model with necessary efficiency to predict the yield through mechanization level index, by scatter diagram and estimating regression lines in 1% probability level. The effective model was estimated with acceptable coefficient of determination 0.851, after removing outliers.
A. Heidari; I. Eskandari
Abstract
A three-year field experiment (2004-2007) was conducted on a silty clay loam soil at Tajarak Research Station of Hamedan to determine proper grain drill for wheat in Hamedan dryland areas. In this study, three grain drills including: Hamedani Barzegar; Sahalan Kesht; and Kesht Gostar with wheat seed ...
Read More
A three-year field experiment (2004-2007) was conducted on a silty clay loam soil at Tajarak Research Station of Hamedan to determine proper grain drill for wheat in Hamedan dryland areas. In this study, three grain drills including: Hamedani Barzegar; Sahalan Kesht; and Kesht Gostar with wheat seed broadcasting and disking were used. The experiment was a randomized complete block design with four replications. In laboratory, the precision of metering device and the amount of seed damage by metering mechanism were measured. At the end of growth season (harvesting time), crop yield and the associated parameters (spike per m2, number of grain per spike, wheat kernel) were determined. Results showed that planting methods did not affect wheat grain yield significantly. However, wheat grain yield was significantly higher for Kesht Gostar grain drill than the other two machines in two drier years. Mean wheat grain yield was 1224 kg ha–1. Mean wheat grain yield was the greatest (1275 kg ha-1) for Kesht Gostar and the least (1174 Kg ha-1) for Hamedani Barzegar grain drill. Mean straw yield was not affected by planting methods. Mean wheat straw yield was the greatest (2349 kg ha-1) for Hamedani Barzegar grain drill, and the least (2009 Kg ha-1) for the combination of seed broadcasting and disking. The amounts of rainfall during growing season strongly influenced wheat grain and straw yields. Mean wheat grain yield was 1572 Kg ha-1 and 1026 Kg ha-1 in wet year and dry years, respectively. This study showed that a wide range of grain drills is adaptable for dryland wheat cropping system for the semiarid Hamedan areas.
D. Momeni; M. H. Rahmati
Abstract
Temperature and humidity are two important parameters affecting the quality and quantity of greenhouse products so two double greenhouses were manufactured in 3.5, 40 and 11 m in height, length and width respectively in agricultural research center of jiroft and kahnooj to study these effects. Both of ...
Read More
Temperature and humidity are two important parameters affecting the quality and quantity of greenhouse products so two double greenhouses were manufactured in 3.5, 40 and 11 m in height, length and width respectively in agricultural research center of jiroft and kahnooj to study these effects. Both of greenhouses are similar in materials, final height, gutter height, covering and field operation but in one of them one heating system, two ventilation fans and one wooden pad were assembled and temperature and humidity besides yield were registered in both of them. The results showed that temperature changing trend inside and outside of the unheated greenhouse were in same phase and this isn't suitable in cold night so the greenhouse with heating system had more yield and picking cucumber fruit numbers than another. Therefore it is necessary to be heated by artificial systems. Because of rapid relative humidity changing in outside of greenhouse in the end of the season, the efficiency of fan and pads cooling system is so low then using of evaporating cooling systems such as fans and pad wasn't proposed and recommend to optimize the temperature by ventilation and shading the greenhouse and in hot days production will be cut.
