Wednesday, September 14, 2011

Water Delivery Structure: Canal Construction Training

A lot has changed in this farmer's garden. He is doing so well that we decided to call a training session to demonstrate the method of constructing a good delivery canal. This method involves a concrete-like soil that forms a very hard surface. With this soil the canal withstands some abuse, and infiltration is greatly reduced over mud or sand canals.

Project coordinator Blessings Malamba teaches farmers how to compact soil at the base of the canal

Mustard greens grow in the foreground, broccoli in the background, an irrigation canal at right
Plastic linings for the canals have been used in the past, but it is costly. This plastic canal lining is a good example so-called "inappropriate" technology. What makes it inappropriate is that the type of plastic that is readily available and affordable is no more effective than the alternative (concrete-like soil), which is cheaper and more readily available. Of course, high grade plastic would be more effective than the soil method, but it is not appropriate to our farmers.
Peas, green beans, tomato, and mustard greens are irrigated from the trench in this photo

A view of a bean field from the water pump
Appropriateness, in the technical sense, is one of the most critical measures of a technology when it comes to predicting the success or adoption rate of the technology. That goes even for the West, where expensive options may still be appropriate. A good example in the West is that all Humvees are outfitted with automatic transmissions. In spite of the loss in performance and increased maintenance costs, the automatic transmission is more appropriate to unskilled drivers.
Lovely tomato

So here we are, deciding how best to get water to the crops. We must take into account more than the crop water requirements and the flow rate of our pump. We must consider the skill, fitness, time availability, and experience of the farmer as well.


After the training on canal construction, the group rides back to the village in the AWP vehicle