Mohammad Jolaini; mohammad karimi
Abstract
Introduction: After wheat, rice and corn, potato is the fourth most important food plant in the world. In comparison with other species, potato is very sensitive to water stress because of its shallow root system: approximately 85% of the root length is concentrated in the upper 0.3-0.4 m of the soil. ...
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Introduction: After wheat, rice and corn, potato is the fourth most important food plant in the world. In comparison with other species, potato is very sensitive to water stress because of its shallow root system: approximately 85% of the root length is concentrated in the upper 0.3-0.4 m of the soil. Several studies showed that drip irrigation is an effective method for enhancing potato yield. Fabeiro et al. (2001) concluded that tuber bulking and ripening stages were found to be the most sensitive stages of water stress with drip irrigation. Water deficit occurring in these two growth stages could result in yield reductions. Wang et al. (2006) investigated the effects of drip irrigation frequency on soil wetting pattern and potato yield. The results indicated that potato roots were not limited in wetted soil volume even when the crop was irrigated at the highest frequency while high frequency irrigation enhanced potato tuber growth and water use efficiency (WUE). Though information about irrigation and N management of this crop is often conflicting in the literature, it is accepted generally that production and quality are highly influenced by both N and irrigation amounts and these requirements are related to the cropping technique. Researches revealed that nitrogen fertilizers play a special role in the growth, production and quality of potatoes.
Materials and Methods: A factorial experiment in randomized complete block design with three replications was carried out during two growing seasons. Studied factors were irrigation frequency (I1:2 and I2:4 days interval) and nitrogen fertilizer levels (applying 100 (N1), 75 (N2) and 50 (N3) % of the recommended amount). Nitrogen fertilizer was applied through irrigation water. In each plot two rows with within-and between-row spacing of 45 and 105 cm and 20 m length. The amount of nitrogen fertilizer for the control treatment was determined by soil analysis (N1). In all treatments, nitrogen fertilizer applied in 5 times until flowering stage. Potassium, phosphorus and microelements applied according to the soil analysis results. The subsurface drip tape was used for irrigation. Tapes with 300 µm thickness, 30 cm dripper spacing and 4 lit/hour discharge were applied. Tapes buried at 20 cm soil depth before planting. Water amount was measured by the volume meter at each irrigation treatment. Water amount calculated based on crop water requirement and plot area and irrigation frequency. On maturity stage, 8 m of two central rows of each plot harvested for determining tuber yields. Water use efficiency was calculated as the ratio of the tuber yield to the total consumed water volume. Statistical analysis was performed using MSTAT-C software. Means were compared by Duncan's multiple range tests at 0.05 and 0.01 significant levels.
Results Discussion: Results of combined analysis showed that yield and water use efficiency (WUE) did not affected by irrigation frequency. Yield and water use efficiency affected by nitrogen level (p
mohammad karimi; J. Baghani; M. Joleini
Abstract
Introduction: One of the serious problems in the further development of maize cultivation is increasing irrigation efficiency. Using conventional irrigation causes a shortage of water resources to increase the acreage of the crop. With regard to the development of maize cultivation, agronomic and executable ...
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Introduction: One of the serious problems in the further development of maize cultivation is increasing irrigation efficiency. Using conventional irrigation causes a shortage of water resources to increase the acreage of the crop. With regard to the development of maize cultivation, agronomic and executable methods must be studied to reduce water consumption. Using drip irrigation system is most suitable for row crops. Hamedi et al. (2005) compared drip (tape) and surface irrigation systems on yield of maize in different levels of water requirement and indicated that drip irrigation increases the amount of yield to 2015 kg/ha and water use efficiency to 3 time. Kohi et al. (2005) investigated the effects of deficit irrigation use of drip (tape) irrigation on water use efficiency on maize in planting of one and two rows. The results showed that maximum water use efficiency related to crop density, water requirement and planting pattern 85000, 125% and two rows, respectively with 1.46 kg/m3. Jafari and Ashrafi (2011) studied the effects of irrigation levels, plant density and planting pattern in drip irrigation (tape) on corn. The results showed that the amount of irrigation water and crop density on the level of 1% and their interactions and method of planting were significant at the 5 and 10% on water use efficiency, respectively. The yield was measured under different levels of irrigation, crop density and method of planting and the difference was significant on the level of 1%. Lamm et al. (1995) studied water requirement of maize in field with silt loam texture under sub drip irrigation and reported that water use reduced to 75%; but yield of maize remained at maximum amount of 12.5 t/ha. The objective of this study was to evaluate the drip (tape) irrigation method for corn production practices in the Qazvin province in Iran.
Materials and Methods: In this study, yield and yield components of corn (SC 704) were investigated under different levels of irrigation water in drip tape systems in one and two rows planting patterns with different plant densities. The experiment was conducted on randomized complete blocks as a split plot (Split block) design with 3 replicates in the Qazvin region. Four levels of irrigation including: 80, 100 and 120 percent of water requirement with drip irrigation (tape) and 100% water requirement with furrow irrigation (control treatment) as main plots and method of planting (one and two rows) with three levels of crop density including: 75000, 90000 and 105000 as subplots were considered. After harvesting, grain yield, number of rows per ear, number of kernels per ear row, number of grains per ear and 1000-kernel weigh were measured.
Results and Discussion: The results of simple variance analysis of attributes showed that the method of planting has a significant difference on the level of 5% for grain yield, but on the other the measured attributes did not have any significant effect. The respective effect of planting method and crop density showed a significant difference on the level of 5% for grain yield, number of kernels per ear and the 1000-grain weight, whereas it did not have any significant effect on the other measured attributes. The respective effects of irrigation method, planting method and crop density showed a significant difference on the level of 1% for the attributes of the number of kernels per ear. The planting in one row resulted in significantly higher grain yields than the other planting patterns. In mean comparisons of the interactions between irrigation methods, crop density and planting method, grain yield in drip irrigation at a level of 120% water requirement in the two rows planting pattern and crop density equal to 75000 plants was shown in the lead on the level of 10%. The results showed that the yields of the treatments were only affected by the method of planting and planting of one row lead the planting of two rows. According to means comparison and water use efficiency in each of the treatments and limitation of water resources, one row planting pattern with crop density equal to 90000 under drip irrigation at 80% and 120% (If there is no water restrictions) of water requirement were suitable.
Conclusion: According to the table of variance analysis, it can be seen that the effect of irrigation on corn grain yield was not significant. Research results of Sorensen and Butts (2005) and Azari et al. (2007) have also confirmed this subject. The grain yield in one row planting method was superior compared to two rows planting method. The superiority of one ton per hectare was statistically significant and substantial. Grain yields varied from 5360 to 12873 kg/ha among the treatments: in drip irrigation at a level of 120% water requirement in the two rows planting pattern and crop density equal to 75000 plants per hectare was 12873 kg/ha and the lowest yield was found in drip irrigation at a level of 80% water requirement in the two-row planting pattern and crop density equal to 75000 plants per hectare as 5360 kg/ha. With regard to mean comparisons of grain yield under the effects of interaction, and water use efficiency for each treatments, I1R1D2, I3R1D2, I1R1D1 and I2R2D3 treatments seem better than others.
M. Jolaini; H.R. Mehrabadi
Abstract
Given the scarcity of water resources using modern methods of irrigation in agriculture will be inevitable. Today, process improvement, development and use of drip irrigation practices as one of the most advanced methods of irrigation in agriculture is increasing. So this study was conducted to determine ...
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Given the scarcity of water resources using modern methods of irrigation in agriculture will be inevitable. Today, process improvement, development and use of drip irrigation practices as one of the most advanced methods of irrigation in agriculture is increasing. So this study was conducted to determine the impacts of irrigation interval and drip irrigation method and their interactions on yield, water use efficiency and quality characteristic of cotton in Kashmar Agricultural Research Station, Khorasan Razavi Province. The study was carried out during 2006-2008. Experimental design was a completely randomized design with four replications. Treatments were included irrigation intervals (2, 4 and 6 day) and drip irrigation methods (surface and subsurface drip irrigation). The results showed that the irrigation methods had significant effect on Yield and Water Use efficiency (P≤ 0.01). There was significant difference between yield in surface and subsurface drip irrigation that was 3074 and 3988 kg/ha, respectively. Water use efficiency was 0.349 kg/m3 in subsurface drip irrigation that was greater than surface drip irrigation. The highest yield and water use efficiency in drip irrigation and subsurface irrigation 4 days, 4315 kg/ha and 0.375 kg/m3 respectively and the lowest with 2 days 3107 kg/ha and 0.265 kg/m3, respectively. Yields in irrigation intervals of 2, 4 and 6 days were 3491, 3725 and 3364 kg/ha, respectively, with no significance difference. The highest water use efficiency and yield were obtained in subsurface irrigation method with 4 days interval as 4315 kg/ha and 0.375 kg/m3 respectively, while the least water use efficiency and yield was obtained in surface irrigation method with 2 days interval as 3107 kg/ha and 0.265 kg/m3, respectively. Finally, using subsurface drip irrigation with irrigation every 4 days was chosen as the best treatment.
M. Joleini
Abstract
Abstract
This study was conducted to determine the impacts of plastic mulch, drip irrigation method and different amount of water and their interactions on yield, water use efficiency (WUE) and quality characteristic of tomato (Mobile cultivar). The study was conducted in Torogh Agricultural Research ...
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Abstract
This study was conducted to determine the impacts of plastic mulch, drip irrigation method and different amount of water and their interactions on yield, water use efficiency (WUE) and quality characteristic of tomato (Mobile cultivar). The study was conducted in Torogh Agricultural Research Station, Razavi Khorasan province. The study was done during 2007-2008. Experimental design was randomized complete blocks (RCBD) in split split plot with three replications. Design treatments included different amount of water (60, 80 and 100% water requirement) in main plot, drip irrigation method (surface and subsurface) in sub plot and mulch (with/without mulch) in sub-sub plot. The combined analysis showed that irrigation water amount, irrigation method and mulch treatments had significant effect on yield and WUE (P≤ 0.01). Yield in 60, 80 and 100% water requirement treatments was 31.141, 54.575 and 62.265 ton/ha, respectively, which showed significant difference. The highest WUE (7.881 kg/m3) was in 80% irrigation treatment, followed by 60 and 100% (with 5.925 and 7.232 kg/m3), respectively. There was significant difference between yield in surface and subsurface drip irrigation (that was 43.380 and 55.274 ton/ha), respectively. Water use efficiency in subsurface drip irrigation was 7.927 kg/m3 that was greater than surface drip irrigation. Yield in mulch and without mulch treatment was 55.641 and 42.714 ton/ha, respectively. Application of mulch increased water use efficiency about 30 percent. Subsurface drip irrigation with 80% water use and using of mulch was the best treatment.
Keywords: Tomato, Deficit irrigation, Drip irrigation, Mulch