جستجوی مقالات مرتبط با کلیدواژه « Furrow » در نشریات گروه « آب و خاک »

In order to evaluating effects of irrigation with saline-sodic water, we conducted three infiltration experiments in clay-loam soil in end-close furrow. We were using 5cm water depth every week, which had EC=12 ds/m and SAR=32. Experiments were done with volume-index method in end-close furrow in third, sixth and tenth irrigation. Therefore infiltration speed and cumulative infiltrations curves were fitted in different times with Kostiakov and Philip models. Results showed that great decrease in infiltration rate was happened since irrigation with saline-sodic water in experiment. Therefore infiltration rate decreased 40.6 and 68 percent from third irrigation to sixth and sixth to tenth irrigation, respectively. So using saline-sodic water can decreased infiltration rate up to 81 percent in 50 days. Evaluation of the simulation results of test data again Kostiakov &loese and Philip model data with RMSE and MBE parameters showed that these models could simulate soil infiltration rate changes good under the effect of irrigation with saline-sodic water. Also simulation accuracy was increased at the end of experience time than initial and mead time infiltration tests

Infiltration in the soil is one of the determining parameters in irrigation, which affects all factors related to irrigation evaluation. On the other hand, spatial and temporal variability of infiltration parameters are a major physical limitation in managing and achieving high application efficiency of surface irrigation. The objective of the present study is to evaluate scaling method in estimating the infiltration equation parameters in furrow irrigation based on Elliott-Walker, Shepard et al., Ebrahimian et al., infilt, Valiants and Milapali methods, and also to evaluation the accuracy of the middle point and end point for the scale process. For this purpose, a reference infiltration curve is considered and then using the time of to reach the middle and end of the furrow, the scale factor of that furrow is obtained. In this research, the measured data for six furrows with soil texture and different input data were considered. According to the results, if the furrow end point is used to calculate the scaling factor in the Scaling method, the accuracy of this method will be significantly increased .Based on the evaluation, Ebrahimian's method had the best results. In the infilt method, there is no noticeable difference between using the middle point and the end point. In many cases, using the middle point in order to obtain the parameters of the penetration equation overestimates the advance value. The simplicity of the one-point scaling method is one of the advantages of this method in comparison with other methods of obtaining penetration parameters

Due to shortage of fresh water resources and increase in the salinity of soil and water resources, use of halophytes has a great importance for forage production and human food security. To compare the effect of different irrigation methods (furrow, bubbler, and drip) on some halophyte forage species, a research was conducted in Sadooq Salinity Research Farm of NSRC in Yazd, Iran, for three years. The experimental design was arranged in complete randomized block design in the form of split plot with three replications, Main plots were different irrigation methods (furrow, bubbler, drip) and halophyte species (A. canescens, A. halimus, A. lentiformis, A. nummularia, and K. indica) were laid out as sub main plots. All plots were irrigated with saline water of 14 dSm-1. During the growing season, all plants were cut every 3-4 months and yield and yield component as well as water use efficiency were measured. Results indicated that A. canescens, followed by A. halimus, with yield of 7.48 and 3.28 ton/ha dry forage, respectively, had the highest forage yield with significant differences (p< 0.05) with each other and with other treatments. Results showed that, under furrow irrigation method, A. canesence and K. indica had the maximum and minimum water use efficiency, respectively. The same trend was also observed for bubbler and drip irrigation methods, as A. canesence had the maximum of water use efficiency under these methods. Based on the results, the highest water use efficiency (2.26 kg/m3) was observed for A. canesence irrigated with bubbler method, and the lowest (0.07 kg/m3) was for K. indica under drip irrigation method. Consequently, based on the results of this experiment and considering the economical and operational aspects of irrigation methods, A. canesence, with dry yield of 7.73 and 8.81 ton/ha under furrow and bubbler irrigation methods, respectively, could be introduced as the best halophyte species for forage production under saline conditions. The results will be more helpful if the experiment is carried out again with determination of water requirement for each plant based on evapotranspiration or soil moisture fluctuations.

Although moving sprinkler systems such as traveling rain-gun are usually designed, so that the instantaneous water application rate which is associated with low pressure is less than the soil final infiltration rate to avoid runoff; there are a growing number of sprinkler systems where potential runoff increases so much causing soil erosion. Moving sprinkler systems such as travelling rain-gun and center pivot can have excessively high water application rates and are prone to runoff problems. This is exacerbated by the trend to low pressure operation, for the reason of saving energy which adds to the problem. The purpose of this paper is to assess, compare and simulate a more fundamentally based approach to predict runoff from sprinkler irrigation systems under moving rain gun conditions on coarse and fine soil textures practiced on both simple plane and ridge and furrow. Experiments were carried out on both simple plane and ridge and furrow plots sloped 0.67 percent with three replications. A travelling rain-gun with length of 200 m was employed to generate rainfall at three different speeds. Results showed no runoff with runoff coefficient of zero on coarse soil. However, a remarkable runoff with coefficient of 0.162 was considered from the fine soil texture on both simple plane and ridge and furrow practices plots, as machine run with the speed of 10 m/hr. Therefore, one of the approaches to overcome runoff problem and increasing irrigation coefficient is using this system over fine soil textures. On the hand, as much as the machine speed is lower, the potential for runoff is larger. In addition to field experiments, there was a good relationship between observed and predicted runoff using EUROSEM. This is because of a high regression coefficient (R > %90) and minimum Residual Mean Square Error (RMSE < 0.2) between them

There are several mathematical models with different solutions for evaluating surface irrigation; one of these models is SIRMOD. In this study, the evaluation indices were analyzed using SIRMOD. In each study field after pertaining field experiments, factors such as inlet discharge, cutoff time, advance and rollback time, infiltration characteristics, geometry of furrow, field length, land slope, and soil moisture were measured and used as model inputs. The water application efficiency was also determined for the current status. Two different solutions were applied for improving the water application efficiency in the study fields; first, cutting off the flow as soon as water reaches the end of the furrow (first scenario), and second, cutting off the flow before water reaches the end of the furrow (second scenario) and then the simulation was executed for the second time. According to the SIRMOD simulation, the average water application efficiency was increased from 35% to 61% for the first scenario and 75% for the second scenario. Results of both scenarios in SIRMOD showed that these two approaches could improve the irrigation Performance of surface irrigation and offer a cut-off time for management of irrigation by farmers.

Potato is one of the main products of agriculture in feeding the world's population and agricultural economy. The production of potato in the world occupies the forth place after wheat, rice and corn. In Iran, annual production of more than 5.5 million tons potato, has made this crop the most important food after wheat. On the other hand, in arid and semi-arid regions, water is the most important limiting factor for production of agricultural crops such as potato. Considering the water use efficiency is one of the most effective ways to deal with the water crisis and increasing the quality and quantity of agricultural productions. Production increasing per unit of water consumed (increasing water productivity) by improving the selection of plant varieties, irrigation management and use of new irrigation methods may be feasible.
Material and The research was performed in the Chahartakhteh research station (32° 18' N. and 50° 55' E.) with 2090 m height above sea level and semi-humid climate with moderate summers and cold winters. Average annual rainfall is about 320 mm mostly during winter. The soil moisture and temperature regimes are Typic Xeric and Mesic, respectively. Soil texture is silty clay.
In order to determine the best method of deficit irrigation for optimizing water use efficiency and yield of two potato cultivars, an experiment was performed in Agricultural and Natural Resources Research Center of Chaharmahal va Bakhtiari farm in 2013. The experiment was based on randomized completely blocks with split - split plot design in three replications. The furrow and tape drip irrigation methods were as the main plots, two potato cultivars as sub plot units and four deficit irrigation managements as the secondary sub plot units including CI(100%), RDI80(80%), RDI65(65%) of available water depletion (AWD) and partial root-zone drying (PRD) during full growth period.
Almera and Burren cultivars are two new cultivars of high yield and quality of early growth period of approximately 90-80 days, high compatibility with Chaharmahal va Bakhtiari climate and more regions of Iran.
Analysis of variance (ANOVA) of studied factors showed that the deficit irrigation management on tuber yield (ton/ha), tuber yield per plant, the amount of starch, soluble sugar, proline, chlorophyll, water use efficiency, and water productivity were significant (P≤0.01). Effects of cultivar on tuber total yield, tuber yield per plant, soluble sugar, water use efficiency, and water productivity were significant (P≤0.01). The interaction between cultivar and deficit irrigation management was only significant (P≤0.05) on tuber yield (ton/ha), proline, water use efficiency and water productivity.
The results showed that Burren cultivar in comparison with Almera was better in tuber yield (19%), water productivity (20%), water use efficiency (19%), and resistance of draught in all deficit irrigation treatments. Maximum tuber yield (59.02 ton/ha) was obtained in Burren cultivar under complete irrigation. Minimum tuber yield (23.1 ton/ha) was obtained in Almera cultivar under deficit irrigation management RDI65 (65% of available water depletion). The maximum water use efficiency (16.79 Kg/m3) and water productivity (14.78 Kg/m3) were obtained under tape irrigation and partial root-zone drying (PRD) treatment. The minimum water use efficiency (7.46 Kg/m3) and water productivity (4.81 Kg/m3) were obtained under furrow irrigation and deficit irrigation management RDI65.
Effect of cultivar was not significant on amount of irrigation water during the growing season. The amount of irrigation water for two cultivars was the same and 4711 m3.ha-1. The amount of irrigation water in the different deficit irrigation managements showed that the highest water use was in CI (5615 m3 ha-1) and lowest water use was in deficit irrigation management RDI65 (4065 m3 ha-1) treatments.
Deficit irrigation management RDI80 ¡PRD and RDI65 in comparison with CI led to reduction of irrigation water amount 16, 21 and 28% of irrigation water amount.
Due to the results of this study, the high consumption of water in agriculture, for optimal use of available water resources, the methods with high water use efficiency and productivity, such as tape irrigation, the PRD irrigation management and the use of drought resistant cultivars is recommended. According to the limitation of water resources, for optimizing water use, the best suggestion for reducing water use on potato, is using Burren cultivar with suitable quality and high yield potential, and deficit irrigation management (PRD).

In order to investigate the effects of furrow irrigation and amount of irrigation water on yield and water use efficiency of corn, an experiment was conducted as a split plot based on a randomized complete block design with three replications for a period of two years at Agriculture Center of Mazandaran. Treatments included three levels of 100, 80 and 60 percent water requirement as the main treatments, and three irrigation methods included fixed every-other- furrow, alternative every-other- furrow and every-furrow irrigation as the subsidiary treatments. Statistical analysis of the results of two year's data showed that treatment with 100% water requirement with every-furrow irrigation and treatment with 60% irrigation water requirement with fixed every-other-furrow had the highest and lowest yield, respectively. The highest water use efficiency was in 60 percent irrigation water requirement with a fixed every-other- furrow treatment and the lowest water use efficiency was related to the treatment with 100 percent irrigation water requirement with alternative every-other- furrow. The value of ky was obtained 0.8 for the total growth stage.

In this study, a complete hydrodynamic model was used to simulate all phases of the furrow irrigation. Two sets of field data, walker and Printz were adopted for the verification of the results. The good agreement was observed among the code, SIRMOD and field data. Then, an optimization scheme was used to determine the best inflow rate and cutoff time in Merkley irrigation. The inflow rate and cutoff time were determined based on the maximum objective function. Therefore application efficiency increased from 57% to 70% and irrigation requirement efficiency increased from 81% to 95%. Then two different scenarios for optimization were determined to obtain desirable efficiencies. In the first case it was assumed that requirement irrigation efficiency and distribution uniformity was greater than 90% and the maximum values for application efficiency to be selected in this area. Application efficiency 60%, requirement efficiency 98% and distribution uniformity 90% were obtained in this scenario. In the second case, it was assumed that requirement irrigation efficiency was greater than 90%, application efficiency was greater than 70% and deep percolation to be minimum in this area. application efficiency 79%, requirement irrigation efficiency 92% and deep percolation percentage 20% was the result of this scenario. Therefore, this numerical model according to desirable efficiencies could be implemented to enhance the surface irrigation scheduling and management.

Distribution of the fertilizer with correct method is the important step for achieving the sustainable agriculture. This study investigates the potassium movement in soil in fertigation, drip and furrow irrigation systems with transplanting the radish crop in sandy loam soil. In this investigation a complete drip and furrow irrigation system was designed in the Research Field of Shahrood. Applied potassium was 100 kg/ha. Fertilizer was applied by fertigation method in drip fertigation system. Also in drip and furrow irrigation systems it was applied with basal application method. After field and laboratory analyses, results revealed that in case of drip fertigation, potassium was confined mostly in the upper layers of the soil i.e. at 0-25 cm soil depth and lower concentration of potassium nearly equal to initial concentration was found in the lower layers of the soil i.e. at 25-40 cm soil depth. Another result of study revealed that in drip irrigation, higher concentration of potassium was found in the middle layers of the soil i.e. 20-30 cm depth and lower concentration was observed in the upper and lower layers. In furrow irrigation, major portion of the applied potassium has moved down in the lower layers i.e. beyond 20 cm and has lead to more leaching losses. Further the drip fertigation in three equal splits was the most beneficial treatment for the growth and yield (15200 kg/ha) of Radish, higher water use efficiency (7.4 kg/m3) and high potassium use efficiency (64%) in comparison with hand application of fertilizer with furrow irrigation/drip irrigation.