Search

Pressurized irrigation technologies of course have the potential to raise the productivity of land and water; but, these technologies could not popularize among the smallholders who own millions of farms worldwide. In developing pressurized irrigation technologies, particularly for field crops irrigation, researchers and manufacturers have developed more specialized and expensive technologies with sophisticated and intricate hardware. These new technologies have benefited only the large and wealthier farmers leaving the smallholders to remain confined with conventional methods of irrigation. This paper discusses the design, performance, and applicability of a low-pressure water sprinkling nozzle, named LERN. This nozzle can be operated satisfactorily over the operating pressure range of 79-117 kPa. The water application rate of LERN is reasonably high, i.e. 20-23 mm h-1; therefore, field crops such as rice, wheat, oil seed etc. can be irrigated quickly and efficiently even at small plots, where available options such as impact sprinklers are, in general, neither feasible nor applicable due to high pressure requirement (196 - 294 kPa), non-divisibility over small plots, and relatively high cost of pumping and system networking. Since the pressure requirement at the nozzle head reflects overall cost of a pressurised irrigation system, LERN holds greater promise in development of a cost effective pressurized irrigation system for irrigating field crop even at small plots. [ABSTRACT FROM AUTHOR]

Water conflict is considered as one of the major challenges in agricultural water management. "Agricultural water conflict" is a term describing disputes and differences among water stakeholders over an access to water resources in the agricultural sector. The purpose of this paper was to investigate farmers’ viewpoints toward agricultural water conflicts. A descriptive correlation method was adopted and the study was conducted in Doroodzan dam irrigation network in Fars province, Iran. Multistage stratified random sampling was used to collect data from 294 farmers. The research tool included a questionnaire whose validity was confirmed by a group of professionals. A pilot study was conducted during which the Cronbach's alpha test was calculated to determinate the reliability of data collection instrument. Findings revealed that, among the groups involved in water conflicts, the main conflict was between farmers and the government. Farmers in downstream were the main losers in water distribution. The dominant water conflict was "latent" as well. The main reasons for agricultural water conflict were "water scarcity", "drought", and "the kind of water management". Farmers' satisfaction toward water management was "low". Farmers’ age, education levels, satisfaction toward water management, and attitude toward geographical and climatic conditions had a significant relationship with agricultural water conflict. [ABSTRACT FROM AUTHOR]

Closed-end furrows are commonly used to irrigate crop in northern part of China. The irrigation performance of furrow in this area is often low. The objectives of this paper are to verify reliability of infiltration parameters and Manning roughness estimated with SIPAR_ID software and present an optimized method for design of closed-end furrow system. The study consisted of field experiments and numerical simulation. Field experiments were conducted in two villages of Yangling district in October 2007. Infiltration parameters and Manning roughness values were estimated with SIPAR_ID software. The estimated values were put into the WinSRFR software, and then the advance trajectory, flow depths in the upstream, and irrigation performance were simulated on each test furrow. The results showed that the simulated values with the WinSRFR software were in excellent agreement with the measured data. Therefore, the infiltration parameters and Manning roughness estimated with SIPAR_ID software were reliable. Later, an optimized model for design of closed-end furrow irrigation system was proposed, based on field data and using the project of Uniform design and the WinSRFR software. Its solution required the use of optimized methodology with genetic algorithm (GA), and the inflow discharge and cutoff time were the independent variables. The results showed that adequate and efficient irrigations can be obtained using closed-end furrows through a proper selection of inflow discharge and cutoff time. [ABSTRACT FROM AUTHOR]