M. Aghajani; Maryam Navabian
Abstract
Water for rice cultivation is one of the main inputs. The new administration of irrigated rice is increase water efficiency and water conservation in the paddy fields. In this research, for optimization of intermittent irrigation management in proportion to water requirement of different stages of rice ...
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Water for rice cultivation is one of the main inputs. The new administration of irrigated rice is increase water efficiency and water conservation in the paddy fields. In this research, for optimization of intermittent irrigation management in proportion to water requirement of different stages of rice growth was present an optimization- simulation model to maximize irrigation water, transpiration and evapotranspiration productivity Indexes. Irrigation water depth in stages of tiller, vegetative, maturity, harvest and irrigation intervals were selected as decided values in optimization model. Simulation of plant growth stages, using the hydrological model SWAP and genetic algorithm was used to solve the optimization model to maximize agricultural productivity. Finally, the optimum amount of irrigation water productivity, transpiration and evaporation - transpiration were obtained 1.60, 2.90 and 1.33(kg/m3) respectively. Results showed, irrigation water productivity index has more harmonize with Sefidroud irrigation network. Also the index is user-friendly in applying and calculating. So according to maximizing of water productivity index irrigation depth was recommended 51, 29, 39 and 11 mm respectively in stages of tiller, vegetative, maturity, harvest and and 8 days period of irrigation intervals to improve water productivity index in Hashemi variety in Rasht. Optimization results showed optimal intermittent irrigation is successive compared with flood irrigation in rice.
M. Navabian; M. Aghajani; M. Vazifehdost; M. Rezaei
Abstract
Abstract
Rice is most important agricultural crop of Guilan province sensibility to salinity and alkalinity of water and soil. In recent years, using of toxicants and fertilizers in farmlands, constructing several dams upstream, entering agricultural, homemade and industrial sewage in to a river, and ...
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Abstract
Rice is most important agricultural crop of Guilan province sensibility to salinity and alkalinity of water and soil. In recent years, using of toxicants and fertilizers in farmlands, constructing several dams upstream, entering agricultural, homemade and industrial sewage in to a river, and drought have decreased gradually discharge of river and increased salinity of Sefidrud River as an irrigation source of Sefidrud irrigation network of Guilan province. This research tries to determine the optimal intermittent and depth of irrigating of rice in proportion to salinity of Sefidrud River using of optimization- simulation mechanisms as is the decrease in crop efficacy become minimum. To achieve this, an agro hydrological SWAP was used to simulate different stages of rice growing and an optimization model was used in a reasonable range of the intermittent rice irrigation period and depth with regard to different growth stages. Because some types of rice are affected by salinity, field experiments of Hashemi variety in Rasht in 1386 were used to calibrate the model. Optimal values of the intermittent irrigation regime in current salinity of the Sefidrud River (1.747 ds/m) included 8 days intermittent irrigation period and the depth of water for irrigating was 1, 3, 4 and 5 for vegetative, tiller, maturity and harvest stages respectively. The comparison of results of optimization- simulation model with field data in 1389 showed good efficiency of this model in irrigation optimization. In the field experiment 8 days intermittent period with irrigation 5 cm in depth was highest crop performance in 2 ds/m salinity.
Keywords: Rice, Intermittent irrigation management optimization, Sefidrud, Salinity, SWAP model
