James and the Giant Corn Genetics: Studying the Source Code of Nature

August 11, 2009

Irrigation in India

Filed under: Uncategorized — James @ 6:49 pm

An article yesterday on the science website yesterday discusses the loss of groundwater in northern India. The technical details of how this are measured* are interesting in their own right. But just keep in mind what the final outcome will be if nothing changes from the way it is today.

The region of northern India supports 600 million people many of them in abject poverty and is drawing 54 cubic kilometers of water a year more than is replaced by rainfall. The end result will be human suffering on a scale even greater than currently found around the world.

What can avert this disaster? Three things:

  • Substantial increases in rainfall throughout the year in northern india (beyond human control)
  • Major breakthroughs in desalinization and pumping (desalinization isn’t my field, so I don’t know how likely that one is, however humanity has been studying the field of moving water from one place to another for thousands of years so the odds of a new pumping breakthrough are slim to none)
  • “Drip” irrigation systems. Most irrigation wastes a lot of water. Drip irrigation reduces waste by irrigating each plant individually (no point in getting the ground between plants wet) and doing so slowly so the water soaks entirely into the ground eliminating run off which both saves water and addresses a major source of agricultural pollution and topsoil loss. The downside is drip irrigation is, comparatively, expensive. Which means someone other than the subsistence farmers who need it would have to pay for it.
  • Water-use efficient and salt tolerant crops. Plants that need less water means less irrigation obviously. The benefit of salt tolerance is in the ability to reclaim land where the earth has become too salty for crops to grow well** as a result of irrigating with salty water, and using that same salty water to irrigate, reducing the demand for fresh water.

I’ve listed these option in what I’d guess is increasing return in investment. Throwing 10 billion dollars are changing the earth’s weather patterns won’t make any difference at all. Throwing the same money at desalinization would have real benefits. Investing ten billion in subsidizing drip irrigation systems for subsistence farms would have a huge impact. It probably wouldn’t cost ten billion dollars to get draught and salt tolerant crops into the hands of the farmers who need them. The benefit of stress tolerant crops is that after they’ve been breed, the cost of actually getting them to those who need them is quite low.*** After all plants, like people, are self replicating. Now if someone would just invent a drip-irrigation system that could build additional copies of itself we’d be set.

*Two satellites orbit the globe and can measure water loss based on changes in their orbit which are caused by variation in the strength of earth’s gravitational field.

**Salt is very bad for plants that can’t handle it. Plowing salt into their farmland is an effective if time consuming method to deal with people you don’t like.

***Especially in countries like India where there is a substantial grey market for things like bt cotton seed.

1 Comment »

  1. Related article: http://www.nytimes.com/2009/09/05/world/asia/05drought.html?hp

    Comment by JS Hoyer — September 4, 2009 @ 10:23 pm

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