J. Nikbakht; V. Eshghi; T. Barzegar; A.R. Vaezi
Abstract
Introduction: In arid and semi-arid regions such as Iran, water shortage and soil absorbable nutrients deficiency are limiting factors of plants growth. Nutrient deficiencies are compensated by chemical fertilizers. The main issue in fertilizer consumption is to use the optimal amount of fertilizer that ...
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Introduction: In arid and semi-arid regions such as Iran, water shortage and soil absorbable nutrients deficiency are limiting factors of plants growth. Nutrient deficiencies are compensated by chemical fertilizers. The main issue in fertilizer consumption is to use the optimal amount of fertilizer that increases water and fertilizer use efficiency. One of the newest and most effective approach for efficient use of water in agriculture is to magnetize the irrigation water. For producing magnetized water, it is crossed through a permanent magnetic field. By crossing water through a magnetic field, its physical and chemical properties improve. The aim of current research was, investigating the effect of urea fertigation by magnetized water on yield, water and fertilizer use efficiency in cucumber cv. Kish F1.
Materials and Methods: This study was performed as split plot experiment based on completely randomized block design with three replications from June to November 2018 on cucumber cultivate Kish F1 at the Research Farm of Agricultural Faculty, University of Zanjan, Iran. The treatments consisted nitrogen fertilizer levels at 5 levels from urea source (0%, 25%, 50%, 75% and 100% crop fertilizer requirement) and irrigation water (magnetized and no magnetized water). The treatment of 0% urea fertilizer and no magnetized water were considered as control. For crops irrigation, tape-drip irrigation system was used and for magnetizing of water, an electromagnetic field with 0.1 tesla was used. The crop water requirements were calculated by FAO-Penman-Monteith Approach on a daily basis using on-time weather parameters data of Zanjan Station. The irrigation frequency was 3 days. During the growth period, fertilization was done as fertigation approach on four times (15%, 30%, 30% and 25% of total crop urea fertilizer requirement). The first fertilization was applied 45 days after planting and the rests was carried out as 10-day periods after first fertilization.
Results and Discussion: The effect of urea fertilizer levels were significant at 0.1% level on yield, water use efficiency, number of fruits and leaf area, at 1% on chlorophyll index and at 5% on fertilizer use efficiency. Magnetized water was significant at 0.1% level on the all evaluated traits, except chlorophyll index. Treatment interaction effects were significant on water use efficiency, urea fertilizer use efficiency and number of fruits at 1% and no significant effect on the rest of traits. Compared with control, the highest and lowest increase in mean chlorophyll index were in 75% and 0.0% urea fertilizer level and magnetized water (21.1% and 0.4% respectively). At any urea fertilizer level, mean leaf area in magnetized water treatment was greater than no magnetized water treatment. Maximum and minimum difference between magnetized and not magnetized water treatments were in 25% and 0.0% urea fertilizer level (155.8 and 143.6 cm2, respectively). Based on treatments interaction, maximum mean of fruits number, achieved in 75% urea fertilizer level-magnetized water (32.8 number). It was 47.7% more than control. Maximum mean of cucumber yields with 50.3 t/ha, were in 75% urea fertilizer level-magnetized water that it increased 17.9, 2 and 3.8 t/ha compared with control, 100% urea fertilizer level-magnetized and no magnetized water, respectively. Results showed that application of magnetized water to irrigate plants, increased water use efficiency. Maximum water use efficiency achieved in 25% urea fertilizer level and magnetized water as much as 17.7 kg/m3. The trend of variations in mean water use efficiency showed, in no magnetized water, by reducing the application amount of urea fertilizer, averages of water use efficiency decreased but in magnetized water treatment, the trend of variations were incremental from 100% to 75% urea fertilizer level. On results, at each level of urea fertilizer treatment, using magnetized water for plant irrigating, increased mean of fertilizer use efficiency compared no magnetized water treatment. Maximum difference between means of urea fertilizer use efficiency at magnetized and no magnetized water was achieved in 25% urea fertilizer level as 74.3 Kg/Kg (367%). The results also showed, the trend of variations in mean urea fertilizer use efficiency at no magnetized water were decreasing from 100% to 25% urea fertilizer level but at magnetized water, the trend was increasing.
Conclusion: based on results of the current research, the optimum urea fertilizer level in Zanjan Region for cucumber is 75% urea fertilizer requirement, which by applying magnetized water to irrigate cucumber plants, mean of yield increases. In this case, in addition to save 25% of urea fertilizer amount, it is also prevented environmental problems.
A.R. Vaezi; H.A. Bahrami; S.H.R. Sadeghi; M.H. Mahdian
Abstract
Abstract
In the Universal Soil Loss Equation (USLE), soil erodibility factor K can be estimated by using a regression equation that has been presented based on field erosion plots in relatively non-calcareous soils. Therefore, it seems necessary to determine the estimating error of the regression equation ...
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Abstract
In the Universal Soil Loss Equation (USLE), soil erodibility factor K can be estimated by using a regression equation that has been presented based on field erosion plots in relatively non-calcareous soils. Therefore, it seems necessary to determine the estimating error of the regression equation in calcareous soils of Iran. This study was conducted in an agricultural area with a dimension of 30 km in Hashtrood province, northwest of Iran during March 2005-2006. The studied soils had about 1.1% organic matter and 13% lime (TNV). In order to investigate the soil erodibility, 36 regular grids of 5×5 km were considered on the study area. On each grid, three standard plots with 1.2 m intervals were established in dryland farming area having a 9% south hill slope. The actual soil erodibility value of the plots was determined as the annual soil loss per annual rain erosivity factor under natural rainfall events. The K value was estimated using the USLE regression equation. Soil physical and chemical properties were measured in samples taken from 0 to 30 cm depth. The results indicated that mean actual value of the soil erodibility factor in the study area was 0.004258 Mg.h.MJ-1.mm-1 which is 10.75 times smaller than the estimated K-factor. There was a poor correlation (R2= 0.16) between the actual and estimated soil erodibility factor. The estimating error values of the soil erodibility varied from 3.173 to 39.298 with a mean error of 9.984. There was a significant correlation between the calcareous soil erodibility and the amount of coarse sand, silt, organic matter and lime (TNV) of the soil. Regression analysis showed that the calcareous soil erodibility significantly (R2= 0.80, p
