Drip irrigation in crop is the slow, even application of low-pressure water to soil and plants using plastic tubing placed near the plants root zone.
Drip irrigation is an alternative to sprinkler or furrow methods of irrigating crop. Drip irrigation can be used for crops with high or low water demands.
Due to his continuous struggle and work regarding drip irrigation, high quality yield was obtained. Specific studies were designed on different salient features of drip irrigation for nourishment of the system. In water scarcity area, drip irrigation system is highly successful. High value crop was revolutionized due to invention of this system in areas of brackish water. Commercial beginning of micro irrigation in its current diverse form introduced and this system was installed almost on 11 million hectares throughout the world.
Drip irrigation is the continuous, slow application of water directly to the surface or into the root zone of the crop (James, 1988). Through drip irrigation a volume of water approaching the consumptive use (CU) of the plants (A.M Michael, 1991). Drip irrigation is the continuous application of less volume of water on and in the soil surface by drip, micro sprayers or emitters (Frenken, 2005). For vegetable production in open environment or in tunnel farming drip irrigation plays the most efficient role. (Locascio, 2005).
Most recent studies conclude that about 12-18 cm of water is applied per irrigation per crop in Pakistan, which is very higher than the actual requirement of the crop approximately 7-9 cm of water between two irrigations. On-farm irrigation efficiencies in Punjab range between 23 and 70%. Continuously increasing demands from house hold, commercial and climatic uses may put additional pressure on water sources, therefore, the increasing demand of food for rapid growing population is a real challenge for many upcoming generations. Now it’s a real challenge for agriculture to produce more food with less quantity of water.
Irrigation is requisite to make production of maize more profitable and for commercial reasons. Maximum profit is obtained, along with other factors, that contents of soil and water be maintained within rather narrow limits throughout the growing season Water Use Efficiency showed that the by lowering the amount of irrigation water received, there would be higher water use efficiency obtained for the drier plant biomass and the tuber yields.
- To compare the utilization effects on water and fertilizer under drip and flood irrigation.
- To compare the effect on crop yield.
- To compare the cost-benefit analysis of drip and flood irrigation.
Frank al., (2010) conducted a study to check the behavior of wheat on various soil with treated water through flood drip irrigation. Gypsum and Sulphuric acid which were applied as basic source. The results showed that the growth and yield of wheat significantly improved by soil characters, height of plant, per plant number of tillers, per tiller quantity of grains and per KG weight of grain. Regarding crop yield, the yield was enhanced by all the inputs, while gypsum applied in deep tillage performed appreciably well. The maximum crop yield of 6800 kg/ha was due to gypsum. So, it can be concluded that in drip irrigation gypsum application proved to be more effective.
Robinin al., (2001) conducted a study in Florida to check the impact of water quality on the production of maize under drip irrigation. Three trials plot were established PD1 (Under drip, better quality water), PD2 (under drip, water marginal quality of water), PD3 (Under drip, bad quality water). Data of plant growth, height of crop, yield and the efficiency of water use were evaluating, and the results reflects that quality of water affects the height of plant, rate of germination, crop production and efficiency of water use. The results show that crop yield (9000kg/ha) and water efficiency (13.92kg/ha-mm) was higher in PD1. The yield in PD2, PD3 treatment was reduced by 5 and 12% respectively. It was concluded that where groundwater quality is low, drip irrigation should be more efficient to get better results.
Starr et al. (2008) stated that during irrigation soil water content should be controlled efficiently to conserve water, and it often improves yield of potato. Four different water management options were evaluated by studying volumetric content (UV) effect on irrigation, plant uptake, and yield in potato hills and replicated plots were studies as well. Measurements of UV using a hammer driven probe were used to derive UV index representing the relative UV status of replicated plots positioned along a hill slope. Time series for UV were determined using time domain reﬂectometry (TDR) probes at 5 and Soil water 15 cm depths at the center, shoulder, and furrow locations in potato hills. Sap ﬂow was irrigation determined using ﬂow collars in replicated ﬁeld plots for four treatments: un-irrigated, sprinkler, surface drip, and sub-surface drip irrigation (40 cm depth).
Drip irrigation and yield of maize crop:
Alam et al. (2005) stated that Govt. of Pakistan is encouraging different ways to use water efficiently production of agricultural crops due to the reason that ever-increasing population of Pakistan limits available water resources. Traditional surface irrigation is being employed by irrigators for more than a century in Pakistan, and this over-irrigation causes not only the water logging but also limits access to already available short irrigation water. It is observed that crop yield per unit of water in Pakistan is the lowest as compared to rest of the world. It has been observed that usage of sprinkler and drip irrigation in Pakistan, India and other countries not only saves appreciable amount of water but also results in higher crop yields with respect to surface irrigation methods. Although, these methods have higher initial investments, but these costs can be counterbalance by saving water and achieving higher production. New water resource development projects should employ these efficient and productive irrigation systems especially in those areas where surface water is available for few months. In this way higher productivity of land and efficient water usage would result in to lessen poverty in those areas along with reduction of the ill effects water logging from irrigation.
Impact of drip irrigation on soil:
Houet al. (2010) performed field experiments under drip irrigation in an arid region of Northwest China during 2006 and 2007. In which effect of the time duration of plastic mulching was observed that how it effects the temperature of soil, the evapotranspiration, growth and yields of potato (Solanum tuberosum), and water use efficiency (WUE). Transparent plastic mulch with thickness of 0.0075 mm was covered on beds of potato from zero days (i.e. No cover) to the entire season to check effects of the duration of coverage. The average daily air temperature was sufficient for potato growth during the two growing seasons, but it reached above 30 .8C for some days.
Daily mean temperature of soil under the plastic mulch was 2–9 8C higher than for non- mulching conditions. It was observed that due to mulching conditions the soil temperature was maximum through the premature growth and became less as the plant canopy increased. It made basis for the different potato growth under different mulch durations for the two growing seasons because of differences in the air and soil temperature between years. Mulching beds need reduced irrigation water; although when mulch duration was increased from 60 days it had little effect on evapotranspiration. Benefits of higher tuber yields, and efficient water usage can be achieved from early stage plastic mulching, and this early stage mulching duration extends to 60 days to get benefits.
Drip irrigation and salinity problem:
Thomas et al. (2010) performed detailed study in USA to check the classical ‘leaching requirement’ approach for salinity management and he observed that for subsurface drip irrigation (SDI) it does not work well because there was no leaching in irrigation with SDI above the depth of the drip tape, and the whole time of the growing season salts will accumulate.
During SDI suitable root-zone salinity is maintained, but accumulation of surface salt will occur until rainfall or other external surface irrigation causes leaching. In this research work it was analyzed that SDI in arid-region soils; very high soil salinity may take place at the soil surface resulting in inhibited germination of small seeded, salt-sensitive crops. It was concluded that following several options can be employed for managing salinity by SDI: (1) leaching can be supplemented by using sprinklers or flood irrigation, (2) transplanting, (3) leaching from rainfall in climates with >450 mm of annual rainfall, and (4) bed shaping to allow planting into soil of low salinity.
- Micro irrigation system over view:
Reinders (2007) stated that watchful selection, complete planning, correct designs and effective management determine the success or failure of a micro-irrigation system. It is certain that demanding irrigation of agriculture will not be reduced rather it would increase almost exponentially. There will be dominance by surface irrigation as the primary irrigation method, but with advanced and efficient the new trends, expansion in the area under micro-irrigation will be observed. Success of micro-irrigation lies in people who dream it, are building it with belief in it and will build great future for it along with its enormous size and because it has been long established.
Drip lines were installed in 1 acre. Before the sowing of maize, lateral lines were spread on the raised beds of the 1 acres of the drip irrigated plot. Main lines and sub main lines were already fixed in the field. The emitters are designed at 9 inches distance in laterals. Control valves and flushing valves were also installed at the field.
Drip irrigation units consists of following parts
- Water pond/Tank
- Pressure Gauges
- Sand Filter
- Cyclone Filter
- Water Flow Meter
- Main Lines
- Sub Mains
- Control Valves
Irrigation scheduling for drip and furrow system:
After germination water was applied for half hour on daily basis in drip irrigated plot then after April 6thApril weather became warmer then water was applied for one hour daily and after 20th April field was irrigated for ninety minutes daily. Before sowing Field was irrigated with drip irrigation for two hours. The discharge of the pump was 15m3/While in furrow irrigated field water applied after 20 days period for one hour twenty mins. Discharge calculated for furrow irrigation is 2.85 cusecs.
The following conclusion were found after the research study
- Drip irrigation system is much better than furrow irrigation system for maize crop because it saves water, enhances yield, conserve energy and a sophisticated technology.
- During this research, it was noticed that for maize crop 71 % water was saved.
- According to the cost ratio point of view, it was concluded that 37% cost saves in drip irrigation as compared to furrow irrigation.
- According to whole study period of research, it was concluded that drip irrigation system is an economic system according to water saving point of view.
The following recommendations and suggestions were made after the research study
- Drip Irrigation system should be adopted by the farmers for vegetable crop such as maize.
- There is a lack of indigenous capacity and technical support to the farmers for installation, Operation and Maintenance of the drip system. There is a need of trainings and courses for the farmers.
- The drip system and its spare parts are not readily available from the local markets, only a limited number of manufacturers, suppliers and technicians are available in the big cities of Pakistan. There is need of its availability in the local market.