Sadegh Afzalinia; Seyed Ebrahim Dehghanian; Khadijeh Alijani; dadgar mohammadi; Seyed Mashaallh Hosseini; Afshar Estakhr; Seiid Mansur Alavimanesh; Mashaallah Zare
Abstract
In this research, effect of tillage and planting methods (planting on permanent raised beds, no-till, and conventional tillage) on soil properties such as bulk density, moisture content, and organic carbon and water consumption, water productivity, and crop yield was evaluated in the form of randomized ...
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In this research, effect of tillage and planting methods (planting on permanent raised beds, no-till, and conventional tillage) on soil properties such as bulk density, moisture content, and organic carbon and water consumption, water productivity, and crop yield was evaluated in the form of randomized complete blocks experimental design with three treatments and six replicates in corn-wheat rotation. Results showed that the raised bed planting had the maximum forage corn (95.33 ton/ha) and wheat yield (7.01 ton/ha) and no-till had the minimum silage corn (87.06 ton/ha) and wheat yield (5.23 ton/ha) which had no significant difference with the conventional tillage. Forage corn consumed the maximum water (9531 m3/ha) in the conventional tillage and the minimum water (8155 m3/ha) in no-till; while, there was no significant difference between treatments from the water productivity point of view. Wheat consumed the maximum water (7177 m3/ha) in raised bed planting, but there was no significant difference between treatments from the stand point of water productivity. Results also showed that conservation tillage methods increased soil moisture content in forage corn planting (around 11%), but had no significant effect on the soil moisture content in wheat planting.
AbdolMajid Moinfar; Gholamhossein Shahgholi; Yousef Abbaspour-Gilandeh; Tarahom Mesri Gundoshmian
Abstract
The four-wheel drive and rear-wheel drive tractors are commonly used in agricultural operations. In order to investigate the effect of a type of driving system a series of tests were performed usin the three driving systems of foour wheel drive, rear wheel drive and front wheel drive in different axle ...
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The four-wheel drive and rear-wheel drive tractors are commonly used in agricultural operations. In order to investigate the effect of a type of driving system a series of tests were performed usin the three driving systems of foour wheel drive, rear wheel drive and front wheel drive in different axle loads of 0, 150 and 300 kg, tire inflation pressures of 170, 200 and 230 kPa and travel speeds of 1.26, 3.96 and 6.78 km/h. Bulk density was measured as an indicator of soil compaction at different depths of 10, 20, 30 and 40 cm. Also, under the different conditions, the drive wheel slip was measured. To carry out the tests, the four-wheel tractor of Goldoni 240 was used which has the ability to work with mentioned driving systems. The experiments were carried out under controlled conditions in a soil channel with the length of 3 m and a width and depth of 1 and 0.6 m, respectively. Test were conducted in completely randomised block design with three repetations and results were analysied using SPSS 22 software. The results showed that by changing the driving system from 4WD to RWD and FWD, there was a significant increase in soil density, with the lowest density associated with 4WD system and the highest density related to FWD. The reason for increasing the density by changing the driving system can be attributed to different slip levels in each of these systems due to the lower slip percentage of the 4WD system than the other two systems. Increasing axial load increased soil boulk density. Of note that with increasing the axial load, the stress was transferred from the surface soil to the subsoil layers. As the axial load on tire increases, the subsoil density was closer to the surface layer. Increased axial load on tire and decreasing tire pressure reduced wheel slip. Stepwise regression model with determination coefficient of 0.92 and according to calculated standard coefficients showed that axial load, soil depth, type of driving system, tractor speed, and finally tire pressure, have the greatest effect on soil bulk density, respectively.
