Wednesday, January 5, 2011

50 kgs ... What is a hectare?

Happy New Years everyone, from the land of sand! We mark time by watching the Zambezi rise; rumor floats down [pardon the pun] from Lukulu that the floods have started in earnest. It's a subtle rise ... the Zambezi winds and twists a great deal, and I suspect much of the flooding is simply a function of the water table rising along with the greater volume of water in the river.

Wanted to take a few minutes to point out another fascinating tid-bit of Zambian agricultural lore that makes life interesting for both farmers and agriculture development types: measurements. In most cases in rural Zambia, commodities produced are measured by volume rather than by weight. The classic example is the 50 kilogram (kg) maize sack; farmers purchase or are allotted grain sacks by the Food Reserve Agency (FRA) that are designed to hold 50 kg of dry maize. The preponderance of maize in Zambian agriculture means that these sacks become the medium of packaging for every other agricultural commodity that is sold: sweet potatoes, paddy [unhulled] rice, sunflowers, groundnuts, and so forth (the loan exception is cotton, of which I'll discuss some other time). However, not all crops are created with the same density as maize; sunflowers and rice, for example, weigh significantly less than maize per unit volume.

What's interesting is that few farmers perceive any of their harvests in kilograms per hectare (kg / ha) [a hectare is 10,000 square meters, or two football fields]; saying that you can increase yields by X number of tonnes per hectare is essentially meaningless. First off, I've never met a farmer with a scale. Second, the idea of weight as a dimension appears to be less tangible than say, a stack of bags of a particular commodity. Third, few farmers have any idea of what a kilogram (or a gram, or a tonne) even is; most farmers in their education have had any opportunity to see anything other than a picture of a scale.

Therefore, I've slowly learned that when talking about yield gains/losses, it is better to utilize the volumetric measurement of 50kg maize grain bags rather than weight. A farmer has a pretty good idea of how many bags of maize / rice / groundnuts / etc. should come off a particular field or paddy, which also gives you some indication of soil fertility. When we get to evaluations of our CF practices, I might push for that measure, as it will give farmers a better valuation of the practice.

That leads into our other question ... hectarage. As I mentioned previously, a hectare is the size of two football [soccer] fields, or 10,000 square meters. There are infinite ways to come up with a hectare: 100m x 100m; 20m x 500m; 10m x 1,000m; 50m x 200m; and so forth. Now imagine you are a farmer with limited access to a GPS, cadastral equipment, measuring tape, and so on; then try stepping out (i.e., pacing) 100, 500, or even 20 meters. It gets a bit tricky, especially given all the tall grass, snakes, holes, etc. Furthermore, I have yet to see a field with a straight boundary; they are all manner of shapes and sizes that are determined by rather complex customary or inherited land tenure systems. I still haven't reconciled that one ... however, it might be helpful to rely on the farmer's basic estimates of a given fields yields and work from there.

A friend of mine working in Liberia told me a pretty enlightening story about how farmers estimated the size of a hectare there ... he kept hearing farmers describe widely varying land sizes as "a hectare". Some farmers described 4 hectares as a hectare; others had an inverse relationship, describing a 1/4 of a hectare as a hectare. After awhile, he realized that farmers were determining the size of a hectare based on what they perceived the fertilizer requirements of a given piece of land were. Because farmers received a fixed amount of fertilizer that was designated for use on 1 hectare, they, not knowing that a hectare was, gauged its size based on where they thought their land needed the fertilizer. A farmer with relatively fertile land spread out his fertilizer over a large area and considered that a hectare, and vice-versa for farmers with infertile land.

In summary ... we need to know where they are at before we can start telling them where to go.

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