This is a project  done by me and my friend s on low cost drip irrigation

Drip Irrigation

Abstract

Despite the impressive gains in global food production over the past half century, an estimated one out of five in the developing world, are chronically hungry. Many of the chronically hungry are poor farm families, who have neither the means to produce the food they need nor sufficient income to purchase it. For them, access to irrigation water, or the means to use the water they have more productively, is a key to increasing their crop production, their incomes and their household food security. Ironically, a technology typically associated with wealthy farmers, drip irrigation, may hold the key to alleviating a significant share of rural hunger and poverty.

In semi-arid areas where water is precious, large farmers use drip irrigation to minimize evaporation losses by delivering water directly to the roots of plants.  At a cost of around $750 an acre for crops like vegetables, current drip systems are not affordable for small farmers in India .

The following innovations may be considered to make drip irrigation affordable to small farmers in India . Some of these innovations are currently being implemented in developing countries like Bangladesh , Cambodia , Nepal , Sri Lanka and Vietnam .

• Bucket Kits consist of a simple household bucket attached to a pole at shoulder height, which supplies a drip line with 26 micro tubes, each of which waters four plants. A starter bucket kit costs $5 in India , including the bucket, and irrigates a 25 sq. meter kitchen garden to feed a family of 6, using 2-4 buckets of water a day. If the family sells some of the crop, they can use the profit to expand their system.

Fig. Schematic of a Bucket Kit

• The Drum Kit uses a 200-liter drum instead of a bucket, and uses five lateral lines to irrigate a 125 square meter plot for a cost of $25. It can be expanded in 125 square meter increments at a cost of $14 for each expansion unit.

Fig. Schematic of a Drum Kit, Micro tube version

• Using Treadle Pumps instead of the expensive Honda pumps and Queen Gil equipment generally used by conventional drip systems significantly brings down the initial setup cost of the system. The $ 30 Treadle Pump is a low-lift, high-capacity, human-powered pump designed to lift five to seven cubic meters of water per hour from wells and boreholes up to seven meters deep as well as from surface water sources such as lakes and rivers. The treadle pump is simple to install and easy to operate by men, women and children. It is ideally suited for irrigation of up to 0.5 hectares of land. The outlet of the Treadle Pump may be connected to the Sub-main line from which the lateral lines branch out.

The treadle pump is a foot-operated device that uses a bamboo or PVC or a flexible pipe as suction/ tube-well to pump water from shallow aquifers or surface water bodies. It consists of a sheet metal or cast iron pump-head, a bamboo frame with two treadles and a bamboo or PVC strainer. The pump-head has two cylinders welded together with a single suction inlet at the bottom and two plungers with or without a rope and pulley. The cylinders are joined together at the base by a junction  box, which connects through check valves to the suction pipe. As pedaling commences, water penetrates the filter and rises up through the suction pipe to the dynamic groundwater level. The action of the two cylinders provides a virtually continuous stream of water.

Fig. Schematic of a Treadle Pump

Fig. Photograph showing a Treadle Pump

Fig. A woman operating a Treadle Pump in Bangladesh

• The investment in the number of plastic drip lines (lateral lines) is reduced by replacing emitters with low-cost micro tubes, configured so that it is only necessary to use one lateral line for every two-three rows instead of one per row. They cost approximately 70% less than conventional drip systems. The shiftable drip system reduces capital cost significantly by using increased labor. This is done by making lateral lines shiftable, so that each line is capable of irrigating ten rows of plants instead of one.

Fig. Schematic of a Drum Kit, Shiftable Hole and Baffle Version

• Pressure Regulators are used to hold pressure steady in the line. The pipe will break if the pressure exceeds 15 psi. Pressure Regulators are used to prevent the pipe from breaking due to excessive pressure.  These are inexpensive and extremely reliable. Also, proper care must be taken during the fitting of the drippers to prevent leakage. If a leak is observed, remove the dripper and try reinserting it properly. In the worst case, remove the dripper, seal the old hole, make a new hole for it.

• Conventional drip systems attack the problem of clogging by putting a major investment in filtration. To keep the cost down, a simple flour sifter (commonly available in the local markets) with pieces of nylon and cloth inserted as filters, that could be washed everyday, may be used for filtration.

• The frequency of plugging may be brought down by replacing emitters with 0.70 mm baffled holes punched by a heated needle. Also, these baffled holes are far easier to unplug than the emitters and the initial investment is also considerably reduced.

• Non Chemical Weed Control

1.      Use of a Pitchfork: By using a pitchfork in a new and/or large bed with little or no existing crop, it is possible to get out most of the roots of long rooted weeds. To use a pitchfork for weed control, push it under a group of weeds and lift them. Shake the soil off the weeds and dispose of them in the compost pile.

2.      Mulch: Mulch is any material placed over soil. It is designed to retain moisture, deter weeds and keep the soil from eroding. As long as mulch is applied thick enough to keep sunlight from reaching the soil, it will keep new weeds from sprouting. You can use shredded and chipped branches, weed free hay, leaves or compost for Mulch.

3.      Weed Barrier Fabric: Weed barrier fabrics are woven polymer barriers that block light for to prevent weed growth yet allow water and air to pass through the barrier.

4.      Mowing: Keeping weeds mowed regularly can be an effective method of reducing the vigor and prevent them from going to seed. Mowing must be frequent enough to prevent the weeds from storing enough energy between mowings . Frequent mowing during the growing season will "starve" weeds and eventually kill the roots, but only if the plant is not given enough time to recover stored energy between mowings. Mowing must be done at least once in 10 days.

5.      Weed Burners: Use a weed burner to destroy surface roots and plant material. A bottled gas weed burner can be inexpensive and effective. The flame only has to be on the plant material briefly to rupture the plant cells and cause tissue death.

• The reuse of drip tape saves cleanup costs, disposal costs as well as material costs and results in conservation of the resources used in manufacturing the drip tape. In case the drip tape needs to be disposed, it may be sold off to those industries which need plastic as a raw material. This method is recommended since plastic is not a bio-degradable material.  

Despite all of drip irrigation's potential benefits, converting to drip irrigation can increase production costs, especially where an irrigation system already is in place. Making the system automated increases the investment costs and it is generally recommended for larger areas of land. Ultimately, there must be an economic advantage to drip irrigation to make it worthwhile.