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ali mokhtaran; abdali naseri; Heidarali kashkuli
Abstract
In the new drainage conditions in the center and southwest of Khuzestan Province, by reducing the depth of drainage installation and controlled drainage, studying the dynamics of the mixing zone, understanding the specifications of this region, and its effect on the flow rate of drainage water and salinity ...
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In the new drainage conditions in the center and southwest of Khuzestan Province, by reducing the depth of drainage installation and controlled drainage, studying the dynamics of the mixing zone, understanding the specifications of this region, and its effect on the flow rate of drainage water and salinity is important. In this study, seven groups of piezometers, each consisting of 8 piezometers placed at different soil depths (0.8 to 5m) and at different distances from the drainage water collector were studied in two research farms, namely, field R9-11 Dabal Khazaei agro-industry (with an average drainage depth of 2 m and distances of 65 m) and field R8-7 in Salman Farsi agro-industry (with an average depth of 1.4 meters and 42 meters distances).Water level in piezometers, water salinity in different soil layers, and drainage water flow rate and salinity were monitored daily in three periods of heavy irrigation of sugarcane (March to October of 2013, 2014 and 2017). Results indicated that by starting a heavy irrigation, hydraulic head increased and hydraulic head variance between bottom layer (4 and 5 m) relative to the surface layers, established vertical flow and saline inflow upwards. Reducing the installation depth of drains up to 60 cm from in R9-11 compared to farm R8-7 and moving away from the collector up to 400 m in each farm, reduced the installation depth of drains up to 40 cm, and increased the hydraulic load by an average of 8-12 cm. The thickness of the mixing area was up to one meter and the reduction of the average salinity line in the mixing area was 8%. It was found that in addition to irrigation water salinity, drainage water salinity was affected by groundwater salinity and the difference in drainage depth, position of the impermeable layer, and the presence of sand lenses. By decreasing drainage depth, the drainage water discharge decreased sharply, such that the averag drainage water from each lateral in farm R9-11 was 10 mm/day, and in farm R8-7 it was 3.3 mm/day. The results showed that with increasing the thickness of the salt and fresh water mixing zone due to the optimal reduction of drainage depth, the volume of water consumed in each irrigation cycle decreased due to plant use of this zone, which can be an effective factor in conserving soil and water resources.
Dorsa Namdarian; Abdolali Naseri; Saeed Boroomand nasab; Masoud Parvizi almani
Abstract
This study aimed to investigate the effect of subsurface drip irrigation on leaf area index, root distribution, quality and yield of sugarcane for the first ratoon. For this purpose, a field with subsurface drip irrigation management was studied. Three measurement stations were selected in the field. ...
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This study aimed to investigate the effect of subsurface drip irrigation on leaf area index, root distribution, quality and yield of sugarcane for the first ratoon. For this purpose, a field with subsurface drip irrigation management was studied. Three measurement stations were selected in the field. The amount of water consumed for this field in 2017- 18, was 19531 mm. During this period, 117 mm of rainfall also occurred. Number of plants, number of green leaves, leaf length and width over one meter of plants row were counted and measured six times at 91, 99, 105, 112, 119 and 128 days after harvesting of plant. Number, length and width of leaves averaged 7.2, 101 cm and 2.9 cm respectively. The LAI value was affected by the number of plants. Weight of 20 stalks, brix, POL, purity (PTY), Quality Ratio (Q.R), brown sugar yield (Y) and white sugar yield (SY) in subsurface drip irrigation were 15.8 kg, 22.2%, 19.8%, 89.1%, 6.7, 21.3 ton/ha and 14.9 ton/ha respectively. Also different root characteristics were measured. Root weight, length, area, volume and diameter were 79.5 g, 707.55 cm, 793.3 cm2, 70.8 ml and 1.05 mm, respectively. Shoot/ root ratio was 5.73 g / g. Finally, in deeper and lower layers of soil, the root diameter is 20% more than the surface layer.
ali Sheini Dashtegol; Saeed Boroomandnasab; A.Ali Naseri
Abstract
To ensure optimal operation of the drip irrigation system, it should be evaluated periodically. This research was conducted to evaluate the technical and hydraulic performance of subsurface drip irrigation system in sugar cane plantation in Sugar Cane Research and Training Institute of Khuzestan during ...
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To ensure optimal operation of the drip irrigation system, it should be evaluated periodically. This research was conducted to evaluate the technical and hydraulic performance of subsurface drip irrigation system in sugar cane plantation in Sugar Cane Research and Training Institute of Khuzestan during growing seasons of 2016-2017 and 2017-2018. For this study, four laterals were selected in experimental field (the first, one third, two third and the last laterals) and four sections including the first, one third, two thirds, and the last were determined on each laterals. Then, the volume of effluent water was measured for three minutes at any measurement point and the system parameters were calculated. Results of the evaluation of the drippers in the laboratory showed that the manufacture's coefficient variations (Cv), coefficient of uniformity (Cu), and distribution uniformity (Eu), coefficients were 15%, 90%, and 84 percent and the values of the exponent x and the k coefficient in the discharge-pressure equation were, respectively, -0.043 and 2.41. Means of Cu, Eu, coefficient of flow variations (Vqs), and Uqs during two growing seasons were 89.2%, 87.8%, 10.3%, and 89.7 percent, respectively. Based on these results, system performance was generally good. Also, by measuring pressure at different points of the system in the middle of the second growing season, the ASAE assessment indicators including: Vqs, Uqs,Vhs, and Vpf were 9%, 91%, 25%, and 13 percent, respectively. Thus, in terms of the overall performance of the drippers and uniformity of distribution the studied irrigation system was considered to be relatively good to good.