Pedal Powered Water Lifting Machine (PPWLM)
Using the PPWLM, farmers can lift tons of water from any depth and store for irrigating crops.

Solution

The Pedal Powered Water Lifting Machine (PPWLM) can be used by farmers to lift tons of water from any depth. When it rains, water levels are high and thus farmers can lift water with less effort. The water can be stored in a container (cheap flexible plastic bags or drums) for future use, especially during drought period. The water stored in a container can be piped to different farms far away from the container. A single machine can be used by many farmers. Farmers can buy the machine for less than Rs20,000/$350 (when mass produced) or rent it on an hourly basis. The PPWLM can lift about 50 liters per minute at it's maximum capacity from a depth of 10m when pedalled by a single person. More people pedalling at the same time would proportionally increase its lifting capacity. PPWLM is approximately 10 times cheaper than a solar submersible pump, requires almost no maintenance, no running cost, is more reliable, locally serviceable in case of malfunction, low noise, no pollution, light weight (appox 15kg) and has less risk of theft.

The PPWLM need not lift the entire water needed for irrigation. It only needs to lift enough water to keep the crop alive till the next rainy period begins, after which rain would irrigate the crops. Even if rain is short, farmers can lift more water with the help of their friends/relatives. If the crop requires more water than what farmers can lift, they can hire people to lift water for short periods or use PPWLM along with small capacity solar pumps or diesel pumps. If solar pumps and diesel pumps aren't available or unaffordable, they still can save part of the crop using PPWLM instead of a total crop failure.

PPWLM in action
http://www.youtube.com/watch?v=_APJLx4jbFI