by Guy Scott
Many years ago I read the first of a number of papers by various researchers addressed to the question: why do different farmers get different crop yields under essentially identical conditions? The author was an agricultural economist who had found himself amongst a group of farmers arguing about this very topic.
Many were the theories advanced by the farmers, as I recall. So-and-so uses more fertiliser, or better fertiliser; Such-and-such ploughs deeper, Van has inherited better soil; and so on. Our man studied the problem in depth for the duration of a season and discovered the truth; a truth that has been confirmed and reconfirmed many times since. Success in agriculture is essentially a matter of temperament, translating into crop yields through an accumulation of small errors (or a lack of errors) caused by an insufficiency (or sufficiency) of obsessive carefulness.
A maize crop, which is what was studied in the original paper, is “processed” by the farmer in about ten stages. These are (with minor variations): ploughing or ripping; seedbed preparation (harrowing); basal fertiliser application; seed placement (planting); early weed control (whether by chemicals or mechanically); top-dressing fertiliser application; late weed control; pest identification and control; control of theft and assorted forms of depletion of the crop; harvesting. Now what our researcher found was this: that small imperfections in the execution of any of these operations caused a measurable reduction in yield.
He also found, of course, that the reductions are cumulative; and that even a quite careful (but not a very-very careful) farmer could take, say, a five percent “hit” on average at each stage. If you have ever looked after a crop from inception to harvest it is very easy to imagine this. Murphy’s law, sometimes called Sod’s law, will see to it that the plough or ripper takes the opportunity to “ride” through the soil, failing to loosen it to sufficient depth.
There will also be some error in the distribution and depth of planting of seed, regardless of whether you are doing it mechanically or by hand (you have only got to look at a few fields of maize to find some where the lines wave around, if hand planted, or even go blank for some distance where the mechanical planter got clogged or ran out of seed). Fertiliser placement is actually a difficult business; it is all very well saying “I have put 200 kg of compound “D” on this hectare”; yes, but have you put 5 grams on every single one quarter of a square meter? Or is it 6 grams here, 4 grams there? (in which case you have lost easily 5 percent of yield).
A lack of a sense of danger easily translates into insect damage (especially when the crop is very small) before the threat is identified and addressed; a lack of a sense of urgency easily translates into slightly late weed control, easily driving down crop yield potential by five percent. And so on: there is almost no point at which a moderately good farmer cannot have done better and saved himself the five percent commission taken by imperfect execution.
Now five percent taken at ten successive stages does not simply add up to 50 percent, since each cut is taken from a crop that has been reduced by previous cuts. Nonetheless, 10 successive reductions of 5 percent each time takes the crop down by 40 percent – reducing a “perfect” yield potential of, say, seven tonnes (depending on the weather) to around four tonnes.
If you are paying full whack for your inputs and receiving normal kinds of price for your product, this is your profit gone! Meanwhile, your next door neighbour, who has no obvious advantage over you, has indeed gone and produced the full seven tonnes, three of which are pure profit! Is he some kind of a witch? No, but he is some kind of an obsessive; ask his wife and she will tell you: “He only ever talks about his mealies, not even rugby interests him.”
A five percent average level of yield loss at each stage is easily achieved; and it is not too hard to imagine farmers or would-be “farmers” who hit the ten percent level. For a ten-stage crop this cuts the yield by two thirds. I estimate that in my kitchen garden (which I leave to the guys to manage) the attrition rate at each stage averages close to 15 percent. This makes a total of an 80 percent yield loss…..
The effect of a given level of yield loss is worse the more “modern” the cropping system. Modern agriculture, as introduced during the green revolution, tends to be very heavy on inputs (fertiliser, chemical, hybrid seed), on financing costs, and on capital and overheads. But yields can be staggering. The system is described as high-input-high-output in economic terms. The potential profits are high but they represent the difference between two high numbers and the ratio of profit to total revenue is not necessarily very high. Certainly, if you knocked 40 percent of the yield off each year’s yield, you would send any commercial farmer into the deadly spiral of fisherman, big game hunter and, ultimately, newspaper columnist.
Sustainable agriculture for small farmers in Zambia essentially has to be low-input-low-output. Thus sweet potatoes or cassava, for example, are ideal crops is suitable areas since they “hate” inputs other than quite a lot of labour. The profit margin is high and easily survives five or even ten percent attrition. The smallholder hybrid maize industry in Zambia, whose roots are deeply political, survives only because of heavy subsidies on the input side. The yield reductions experienced by most farmers are tolerable only because the cost of production is kept down (and the price kept up) to overcome the imperfections in the production process.
Even then, many producers go further and spread the fertiliser more thinly than the theoretical optimum because they instinctively know that the so-called optimum is not appropriate given the process of creeping losses than I have just described.
What makes a very successful farmer? It is a question that has taxed observers for millennia. On the one hand, the job description demands many feminine qualities; after all, much of a farmer’s time is taken up obsessively (that word again) nurturing and protecting baby plants and animals. He can talk as tough as he likes, but he cannot deny his track-record as a midwife and wet nurse to various delicate life-forms.
But at the same time agriculture is a very violent and thus masculine activity – though the immediate signs of the violence may have vanished by the time you come upon the scene. The farmer is a destroyer of forests to make fields, and of all forms of wildlife that may threaten his selected plants and animals.( Think of the Amazon rainforest!) He is also, historically, and unlike the hunting-gathering peoples, a maker of systematic and large scale wars to protect or steal the fruit of his or others’ labours.
February 28, 2010
by Guy Scott