Perspectives and questions

Hmmmmm.......

I think it will help (help me, at any rate) to identify what we aim to do here. "Consolidate new analysis" - OK, but to what end? How will we know when we have arrived at a meaningful end point? Is it a book or paper? An identification of knowledge gaps and a proposal for research to fill said gaps? A recipe by which third world farmers will gain more food from their water? And, if so, how will we know that the recipe works? And if the recipe is already in the literature and known to work, how does a blog help?

Because this is the CPWF, I assume we want a recipe by which third world farmers will gain more food from their water. Note that I do not imply that the farmers will necessarily be the ones to receive and implement the recipe. It might be that the recipe is for policy makers who, through the right policy, might get better land management which leads to more food from the water. Or whatever.

I assume further that a book or a paper would be an interesting by-product, but not why we are really doing this. And I assume that we think enough is known to get to a good end point without writing a new research proposal.

If we want a robust, rationale debate of stuff already known, which is presumably the reason to have a blog, have we got the best group to arrive at the end point? Many not represented here have written papers about water productivity.

If we want more food for third world farmers, do we restrict ourselves to water and water productivity? Many other things limit production and productivity - land, labour, fertiliser inputs, and so on. Would we be satisfied if we could raise land productivity by producing more from the same land, but with more water, such that the water productivity remained constant? In principle, this can be achieved in any river basin in which yield is below potential and also from which water is discharged to the sea. I assume we would be satisfied because, if not, there is a harsh counterpoint. If, in some basin, water productivity were at a maximum, and a growing population would be reduced to starvation and misery unless land productivity were raised, a disinterest in raising land producitivity would surely lead to that starvation and misery. If we don't want that, then we aren't simply talking about water productivity.

To pick up a point from an earlier post, one can give examples with fish or livestock that are equivalent to the agriculturally biased points in the previous paragraph. Fish in aquaculture can be thought in terms of fish per unit area (of land or water, it doesn't matter), or a land productivity, which we can imagine maximising without changing the water productivity. Is the spectacular rise in aquaculture production in the Mekong delta an increase in land productivity, water productivity or both?

It is interesting to think about dry and wet (semi-arid and humid) river basins. In the latter, over most of the area most of the time, food production is likely to be limited by things other than water. In NE Thailand, in the Mekong Basin, for example, we know that water is scarce in the dry season, but mostly the place is wettish. We also know that rice productivity is very low there, amongst the lowest in the Mekong - perhaps a consequence of limited water? Well, not really. Sugar production is very high, amongst the highest in the Mekong. It would seem to me that we must search for other explanations, and they are likely to be found in the different management and inputs of a subsistence crop (rice) and a commercial crop (sugar). Based on this, and the fact that rice production has been rising slowly but surely for years, I am confident to predict that it will continue to rise for the foreseeable future. Water productivity of rice is increasing, as is land productivity, but I think the main factor is better management and inputs. (Incidentally, Andrew Noble disputes my analysis that rice productivity is likely to increase, and he knows much more about rice in the Mekong than I do. Notwithstanding, I'd bet him a bottle of red that, barring unforeseen disasters, wars, political upheaval, etc., it will continue to rise.)

Let's look at a dry basin. If it is closed, with no water or no water of useable quality reaching the sea, then the an increase in food production must also be an increase in water productivity. If there is irrigation in the basin, it is almost certain that there is a way to do this which is dead easy, but may not be economic. It is almost certain that current irrigation maximises production across several inputs, but especially capital, labour and land. Even in a water scarce basin, production is almost certainly not maximised with respect to water. So, the very simple way to increase water productivity is to spread the water thinner, over more land. If you use that water to add to rain, you maximise the cropping from limited rain. Something of this sort is currently occuring in the Murray-Darling Basin in Australia. After years of drought, the dams are run near dry, and rice farmers (a major irrigation crop in the southern part of the basin) are allocated much less water than they are used to, and less than they need to grow rice. So, some have turned to growing winter cereals, using their scarce water as supplmentary irrigation to finish the crop which is grown mostly on the rain.

Another perspective which offers insight is that of scale and efficiencies. A farmer might increase his water productivity and overall production through more efficient use of water, ensuring more of it gets to the crop. He has increased his irrigation efficiency. The consequence, however, is that less water flows back to the river (or groundwater) and less is available downstream. Loss of production downstream may mean that there is no gain in efficiency or water productivity at the basin scale. The efficiency argument here is well known, but we see that it might be applied to water productivity as well. Are we targetting the farmer or the basin for improvements in productivity? And are we really interested in productivity or production?

So many perspectives, so many questions!