Irrigation system provide explanation to the increase the production of the agricultural sector. The management operation of irrigation systems is important aspect to gain the success in the production of crops and orchards. The purpose of this article is to consider knowledge and investigations that identify the principal criteria and processes to operate the irrigation systems for promote the agriculture more productive and viable.
The layout of systems must have its base in requirement that are suitable, which signify to take into account agronomic, economic, soil related, hydraulic and environmental factors. The layout and managing of irrigation systems at filed level is an aspect of the first importance for an efficient use of water, economic enhancement of the agriculture and its environmental viability.
Mostly Water required by plants is supplied in the form of precipitation, but when it could not supply as demanded by plants, it is then mandatory to supply artificially irrigation. There are a lot of irrigation methods available that depends upon water availability, crop, soil properties, field topography, and theirs cost. The production and growing of crops depended on irrigated agriculture where natural source of water is not enough to provide water for growth. Mainly production depended on irrigation design and proper management.
Proper management of available water at farm level is required because of increasing need, finite resources, ground water table change in space and time, and problematic soils (Kumar and Singh, 2003).Proper water irrigation management at farm is one of the basic source in beneficial operation and management of irrigation system. Irrigation water management consists irrigation time, the amount of water application during each development stage of plant, and operating and managing the irrigation system.
Dynamic and efficient irrigation schedules requires the authentic determination of water need for the crops to help the farmers to decide irrigation numbers and time of irrigation. New emerging technologies such as remote sensing, crop modeling, and lysimeter are contributing to get a productive knowledge of the crop irrigation. New Irrigation technologies helped the farmer to apply the proper irrigation to crop for better yield. Different Irrigation systems are applied , designed and managed to supply the need of a crop on the field.
Proper management controlled deep percolation, runoff, evaporation, and application losses to establish economically production process. Playán and Mateos (2006) shared that technologies in irrigation systems at field level depend on the water availability, climate distribution, type of crop and soil ,the social and economic circumstances, and the distribution system.
Water Resources
The major sources of Irrigation water consisted on groundwater, land surface water (rivers, lakes or reservoirs) or from non- conventional ways like treated wastewater and saline water, drainage water, or fog collection. Mostly irrigation source is using surface water, also called floodwater harvesting. In form of a flood, water is transferred to normally dry river beds using a network sources of dams, gates and water channels and spread in large areas. The soil moisture contents stored in soils particles will be used to grow crops. Surface water irrigation areas are in particular located in semi-arid or arid, mountainous regions.
The term Floodwater harvesting is considered as a irrigation method, rainwater harvesting is usually not considered as a form of irrigation due to natural phenomena. Rain water harvesting method is the acquiring of runoff water from home roofs or unused field. Globally around 90% of wastewater remains untreated, causing serious water pollution. This untreated wastewater mostly used as a source of irrigation water in agriculture sector. City areas provide fruitful markets for fresh produce, that are engaging to farmers.
The International Water Management department has worked worldwide in many countries like India, Pakistan, Vietnam, Ghana, Ethiopia, Mexico and other countries on many projects with aimed of assessing and reducing risks of wastewater irrigation. These consists irrigation termination few days before harvesting to die off pathogens in the sunlight, application of water carefully so it does not effects leaves. The World Health Organization has provided guidelines for safe water uses.
There are many benefits of utilizing recycled water for irrigation purpose ,consisting the low cost (comparatively with other sources, especially in an urban area), regularity of supply , and common consistency of water quality. Application of recycled wastewater is also considered as a source of fertilization and plant nutrients supplements for plant, but regular application of wastewater carries risk of soil and water pollution. So, a compiled understanding of soil water conditions is important for effective use of wastewater for irrigation purpose.
Irrigation Systems
Irrigation Systems The efficiency of irrigation system mainly depended on layout and management of systems according to farm requirements. Designing of irrigation system effects on application efficiency and involves many variables and restrictions, whose key objective is to increase benefits and minimize application costs. In a well-organized efficient irrigation system, a set of assists produces maximum benefits. To attain this, a balanced process promoting the design and operation of application systems in agriculture is needed due to many feasible combinations of design variables that satisfy irrigation requirements.
Application of Irrigation systems varies on based in several factors, which the most beneficial for crop, soil, topography, water sources and its quality. The application efficiency of different irrigation methods alter and depends on its designing, management practices, and operational methods (Holzapfel and Arumí, 2006). Definitely, well-managed and designed irrigation systems will have the maximum irrigation efficiency and water circulation levels, which surely give profitable output.
For an proper management steps and operational application of the surface irrigation systems, a sequence of support factors have been developed, along with simulation models and control and derivation formation, such as adduction systems. This is very important for the irrigated agriculture area and a basic factor due to the competition of different water resources. In the last few years, many irrigation methods have upgraded significantly the application efficiency at farm level, improving the management of irrigation water application. For example, Mexico, announcing new technologies and more beneficial associated with real-time irrigation application, demonstrated water conserving in the order of at least 20%, without any decrease in crop production.
Some research have showed the differences in irrigation efficiency for several irrigation systems have different uses efficiency, like furrow irrigation, sprinkler irrigation and trickle irrigation, and efficiency systems were analyzed in Southern New Mexico, USA, with onion yield. So, best beneficial irrigation water use efficiency (IWUE) was noted using the sprinkler irrigation system. The minimum irrigation water use efficiency data were achieved under furrow irrigation systems and subsurface drip compared with sprinkler irrigation was due to more irrigation under subsurface drip and higher evaporation rates from fields using furrow irrigation system.
Comparison of irrigation systems
Bragimov et al. (2007) compared irrigation application efficiency of drip and furrow irrigation .He analyzed that 18-42% of the irrigation water can saved with drip systems with comparison of furrow system and irrigation water use efficiency increased by 35-103% if compared with furrow irrigation system. Another research was made by Maisiri et al. (2005) in a semi-arid agro tropical climate area of Zimbabwe. He noted that drip irrigation used around 35% water of the surface irrigation systems, giving higher efficiency. The gross margin scale for surface irrigation was high than drip irrigation system.
Another experiment analyzed efficiency of surface and subsurface drip irrigation systems in Turkey. Both methods had same production results but comparatively surface drip had more benefits due to complication in replacement and higher expenses for subsurface systems. He also discussed about the surface drip system in early potato under Mediterranean method impacts positively many of the physiological cycles and technological parameters in semi-arid circumstance, as compared to low-pressure sprinkler irrigation system.
Hanson and May (2004) got more yield when drip irrigation system was used compared to the sprinkler systems with same amounts of water application; additionally, drips application systems minimized percolation below the root zone area. Another experiment research observed that low-energy precision operation and trickle irrigation for cotton in Turkey, summarizing that both systems can be used successfully in the arid climatic circumstance of this Region.
Irrigation efficiencies
Irrigation efficiency in agriculture evaluate the profitable use of water in irrigation system. It includes decisions of irrigation water management, including application timing and amount of water. All misfortunes in giving the arranged water system water to the zone flooded Water the board choices emphatically impact application efficiency for surface frameworks, while physical site circumstance and water system offices control to a more prominent degree how uniform water can be connected in sprinkler, miniaturized scale, and subsurface frameworks. Application efficiency is generally measured as the irrigation system circulation uniformity.
How efficiently water channels and pipelines transits water are described conveyance efficiency. Sprinkle, surface, micro and subsurface are the generally used irrigation methods. One or more irrigation method form can be used to apply water. For example, we can use graded furrow, graded border, level furrow, and basin systems application of water using the surface irrigation system.
The most applicable method and system for a farm depend upon physical farm conditions, crop type, time and amount of water availability, and managing skill availability. However, a well management of appropriate irrigation method is required to attain high irrigation efficiency. New irrigation method are more efficient to irrigate the field uniformly. Plant absorb the amount of water that is its requirement, neither too much nor too little. Water use efficiency of a field can be measured as follows:
Field Water Efficiency (%) = (Water Transpired by plants ÷ Water Applied to Field) x 100
However, water shortage is a critical issue to farming in many regions of the world. With reference to agriculture, the World Bank targets food production and management of water as an increasing world issue that is fostering a focusing debate. Physical shortage of water is where there is no enough water to fulfil all demands, consisting that needed for efficient function of an ecosystem. Generally arid areas suffer more from physical water shortage. It also occurs where water sources seem enough but resources are over-committed.
Therefore, design of an irrigation system maximize balanced application as well as save water losses caused by improper management practices, evaporation from soil, wind drift, runoff, or deep percolation produce the more irrigation efficiency. There are a lot of aspects on which efficiency of irrigation depends like which irrigation method used, physical condition of the irrigation system, physical properties of the soil, crop type, plant to plant spacing and population, irrigation timing and amount of irrigation water applied, water management and skill, and ecological conditions.
The loss of water varies with the form of irrigation method and system operation, the environmental circumstances under which the system is running, and the type and condition of conveyance system. A proper designed and installed system that fulfil demand of the crop, water, and site circumstances, water management is the basic key means to ensure minimize losses. In the absence of proper irrigation scheduling, the common phenomena are to over water application, resulting in more runoff and deep percolation.
Application efficiency (Ea)
It is the proportion of the ordinary depth of irrigation water penetrated and stored in the root zone area of plant to the average depth of irrigation water applied. Application Efficiency Low Quarter is the proportion of the ordinary of the lowest one-fourth of amount of irrigation water infiltrated to the average depth of irrigation water infiltrated. This term is mostly used in expressing management efficiencies. The maximum water loss commonly results from applying excessive water. In all conditions management of irrigation has a large impact on the net quantity of water available for proper use.
Application efficiency is basically by affected water management decisions. Evaporation losses depends on which irrigation method is used, system used, and system operation practices. Water irrigation management is essential with all irrigation systems. This is right for sprinkler irrigation systems because the effects of drops on the soil surface can minimize surface water storage and can create a surface seal that minimize infiltration. The word that is mostly used to explain management efficiency is application efficiency.
Irrigation application efficiency is a basic function of water losses, a high cost does not mean an efficient and uniform irrigation. For example, deep percolation and runoff of irrigation water can be eradicated by critically underwatering. If deficit water is stored in the root zone of a plant to fulfill the crop water requirements, crop yield will be minimized. Therefore, a more efficient explanation of an effective irrigation should build the concepts of adequacy and uniformity of application. (See equations below.)
Conclusion
The design and application method of irrigation system influence the application efficiency and involves many variables and constraints whose basic objectives are to enhance benefits and minimize costs of production. Proper designing of irrigation systems is a very important subject to develop irrigation application, efficiency and economic recovery in the production. The design and type of irrigation system must be mainly related with information on irrigation, hydraulic processes, economic, environmental and agronomics aspects specially crop type.
The efficient systems at farm level appears to be an important form for the irrigated agriculture and basic key element due to the competition for water resources with other sectors and to permit the economic and ecological suitability of agriculture. Generally, both surface irrigation and pressurized irrigation systems can obtain a reasonable level of efficiency, when these are properly designed and operated and selected for a site-specific condition. So, it is important to select irrigation design and type of irrigation after considering all the aspects related to irrigation to increase water use efficiency to get more yield.
References:
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Muhammad Roman 1, Sadam Hussain 2, Sarwan khan 3
School of Soil and Water Conservation, Beijing Forestry University, China.