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

Due to the lack of water resources and excessive evaporation in the country, it is necessary to have a detailed irrigation program and a suitable management method. The present research was conducted to investigate the effect of superabsorbent and mulch in Khorramabad in July 2022 in a factorial combination with a completely randomized design in three replications. The first experimental factor was irrigation water treatment in 4 levels including irrigation that provided 100% water requirement (I100), 80% of crop water requirement (I80), 60% of crop water requirement (I60), and 40% of crop water requirement (I40). The second factor included different corrective materials including plant mulch (M), superabsorbent (S), and control treatment (I). The results showed the maximum amount of wet and dry yield and crop height was related to I100-M treatment, i.e. 100 percent water requirement and compost corrective material, which were 89.52 tons per hectare, 29.42 tons per hectare, and 2.27 meters. The maximum wet and biological productivity for I40-S was calculated as 14.24 kg of wet matter per cubic meter of water and 4.75 kg of dry matter per cubic meter of water. The lowest wet and dry yields were related to I40-M, which decreased the yield of the control treatment by 6.5 percent and 0.9 percent. The lowest productivity was related to the I100-S treatment, which was calculated as 3.13 kilograms per cubic meter of water for biological productivity and 9.14 kilograms per cubic meter of water for wet weight productivity. In general, mulch had a better performance in the treatments where the water stress was low, but when the water stress increased, the performance of the mulch treatments decreased. In the superabsorbent matter, the treatments with complete irrigation or with less stress, yield decreased, but the treatments with increased stress showed better results than most of the corrective materials and the control treatment.

Reforming the cultivation pattern is a program that the government pursues with the aim of achieving sustainable agricultural development and maintaining food security.Protection of basic production resources,self-sufficiency in the production of basic products and maintaining agricultural employment are among the goals of this program.In this regard,this research was carried out with an emphasis on the protection of water resources in the Kabudrahang plain of Hamadan province.Using linear programming modeling for the studied area, optimal patterns were determined. Water resource protection policies were examined and tested with two scenarios of reducing the use of underground water by 30 and 50% and the scenario of self-sufficiency in wheat production.The results showed that the water resource protection policy reduces the planned efficiency of the cultivation pattern from 2.44% to 24% compared to the current pattern.The area under cultivation of rainfed crops also increased and the area under cultivation of irrigated crops decreased.The area under cultivation of cucumbers and tomatoes increased, but the area under cultivation of fodder and water grains decreased.Self-sufficiency of wheat under the conditions of the existing and optimal cultivation pattern was achieved, but in the scenarios of water resources protection,self-sufficiency was not possible without applying the condition.Under the scenario of self-sufficiency of wheat, the planned efficiency and the use of labor decreased more than the scenarios of protection of water resources.According to the research findings, in order to protect water resources and sustainable exploitation of these resources,it is necessary to control and reduce their exploitation by 30 to 50 percent.

To monitor and compare the changes of salts in the soil profile around the roots of the corn plant, the plant yield, and the productivity of corn water, an Experimental was conducted in a completely randomized block of three repetitions in two crop years 2017-2018 and 2018-2019 at Ahvaz Agricultural Research Station. Experimental treatments included two subsurface drip irrigation systems with a working depth of 30 cm from the soil surface and tape irrigation and two irrigation intervals of 2 and 4 days. The results of monitoring soil solutes obtained from sampling depths (0-25, 25-50, and 75-50 cm) showed that soil salinity in the second year in both systems as a result of improving the quality of irrigation water from 3.61 dS/m to 2.01 dS/m, it was reduced by two times. The results of soil salinity monitoring showed the highest ratio of salinity reduction with a 2-day irrigation interval in both irrigation systems. The most leaching was done at the irrigation depth of 25-50 cm in the subsurface drip irrigation system and at the depth of 0-25 cm in the tape system. The highest yield of corn dry fodder was 9.13 and 7.13 tons per hectare, respectively, and the best water efficiency based on dry corn fodder at the rate of 13.74 kg/m was obtained in the strip drip irrigation system (tape) with a two-day irrigation interval and in the second crop year. Also, the results of the soil salinity measurement showed that the implementation and exploitation of the drip irrigation system can be the basis for improving the quality of the soil as the most important non-renewable resource of agriculture.

Precipitation deficiency, its uneven spatio-temporal distribution, groundwater decline, and water loss in traditional irrigation systems, make it necessary to introduce appropriate solutions to improve the soils in arid areas. Meanwhile, the optimal use of rainfall, should be a priority in water-scarce areas. Achieving these objectives can be an effective factor in reduction of irrigation costs in planting projects in desert areas. The effect of these supplements on plant traits has been less studied. In this regard, the effect of Abyar and Absar irrigation supplements on the amount and duration of irrigation and soil properties of planting areas has been investigated. Therefore, this study investigates the efficiency of different concentrations of two irrigation supplements on some morphological characteristics (plant traits) of A. canescens in vitro conditions.

A completely randomized design with three treatments and three replications at concentrations of 1:1000, 1:2500 and 1:5000 in a five-months period under greenhouse conditions. In addition, the structural and biomass traits of aerial and underside of A.canescens rootstocks were measured in different treatments. At the end of the research period and removal of seedlings from the soil, plant traits of aerial parts and subsurface, including; shoot length, shoot weight, shoot dry weight, and increase shoot height and root length, root weight and root dry weight were measured for each replication. The statistical analysis was performed by using Duncan test.

The results showed that the effect of supplements on root length and fresh and dry weight of the plant was not significant. Based on the results, the effect of supplements on root width was increasing and had a significant effect at 95% confidence level. the effect of supplements on the length, weight and dryness of the shoot was significant and increasing. However, the effect of supplements on increasing the height of the aerial part was significantly reduced at 95% confidence level. Overall, an increase in the concentration of the supplements showed a negative effect on the structural and biomass traits of aerial and species. Therefore, the use of irrigation supplements with low concentrations (1:1000 and 1:2500) for structural and biomass of A.canescens transplants is recommended in greenhouse conditions and before their transfer to the natural environment.

The use of Abyar & Absar, has negative effects on the structural and biomass traits of aerial parts and root of A. canescens. Also, it had a significant effect on root width only among root characteristics. The effect of supplements on the amount of root length and their wet and dry weight was not significant. The effect of supplements on the width, length, weight and dryness of the shoot was significant and increasing. It is suggested to investigate the effects of irrigation supplements on plant traits and characteristics of different species in different field conditions as well as other concentrations.

Due to water shortage in the country, improving the irrigation management of potato fields can reduce water consumption and increase the efficiency of this important product. For this purpose, it is necessary to have sufficient and accurate information about the status of applied water and water efficiency in the conditions of farmers' management. Therefore, the amount of applied water, yield, and water efficiency in the conditions of farmers' management in two major potato production areas in Razavi Khorasan province were investigated. The two areas of Fariman and Torbat Heydariyeh with the highest area of cultivation and production of potatoes were selected as pilots cities. The method of irrigation in all fields was the drip method. In experimental farms, irrigation and agronomic characteristics, water source and irrigation network characteristics, required meteorological data, applied water volume, potato yield, and water efficiency in the crop year 2019 were measured. Also, the volume of water used by farmers was compared with the estimated irrigation needs based on meteorological data from 2019 and the last ten years calculated by the Penman-Monteith method. The amount of applied water based on meteorological data in 2019 was about 26% and to 10-year statistics was about 15% more. The results also showed that the volume of applied potato water in the studied farms varied from 9888 to 14573 m3/ha and its average was 11885 m3/ha. Potato yield in selected fields varied from 28600 to 60000 kg/ha and the average was 40399 kg/ha. Water efficiency varied from 2.22 to 5.25 and the average was 3.42 kg/m3

In arid and semi-arid regions, water resource management and optimization of applying irrigation water are particularly important. For optimization of applying irrigation water, the estimated values of actual evapotranspiration are necessary for avoiding excessive or inadequate applying water. The estimation of actual crop evapotranspiration is not possible in large areas using the traditional methods. Hence, it is recommended to use remote sensing algorithms for these areas. In this research, actual evapotranspiration of wheat fields was estimated using METRIC algorithm (Mapping EvapoTranspiration at high Resolution with Internalized Calibration), using ground-based meteorological data and satellite images of Landsat8 at the Faculty of Agriculture, Shiraz University, in 2016-2018. In the process of METRIC execution, cold pixels are located in well-irrigated wheat fields where there is no water stress and maximum crop evapotranspiration occurred. The estimated maximum values of evapotranspiration using the METRIC algorithm were validated favorably using the obtained values by the AquaCrop model with NRMSE (Normalized Root Mean Square Errors) equal to 0.12. Finally, the values of water productivity (grain yield per unit volume of evapotranspiration) and irrigation efficiency were estimated using the values of predicted actual evapotranspiration using remote sensing technique. The values of measured irrigation water and produced wheat grain yield in 179 ha were estimated at 0.86 kg m-3 and 75%, respectively.

Water consumption management and optimal operation of reservoirs are important challenges for sustainable development in arid and semi-arid regions of the world. Increasing water consumption productivity is recognized as an adaptive strategy for coping with drought conditions and increasing water demand due to population growth. Nonetheless, the impact of the increase in water consumption productivity on the operation of reservoirs is neglected in assessment as a management tool. Therefore, in this research, the impact of the increased efficiency in agriculture water on Jareh-Dam operation as a case study has been assessed. For this purpose, an objective function has been developed based on the coefficient of water efficiency to optimize the water release and water storage in the Jareh-Dam. The operation reservoir is then compromised in both optimal and current conditions with considering the four scenarios of water efficiency. Results show that increasing in the coefficient of water efficiency up to 0.5 will result in an increase of 10 percent in the reliability and a 28 percent decrease in the vulnerability. Also, assuming the reservoir performance is constant compared to the base period, with a 17 percent increase in downstream consumption efficiency, a growth of 46.7 percent in the region's gross income is not far from expectation.