WHARF: World Hunger Alleviation through Response Farming

A Few Home Truths:

  Essentials for Sustainability: What Must Occur to Continue Farming in Place?

1. The family must survive, and their quality of life and financial position must improve. Only this will slow population growth, now requiring farm land expansion and ever greater unit yields.
2. Soil erosion must be prevented, and soil fertility and tilth must be improved - a reversal of todays seemingly inevitable degradation.
3. Survival requires a constant food supply, demanding absolute minimization of crop failures, and at least subsistence level production in virtually all drier seasons. It also requires boosted yields in moderate rainfall seasons, and still greater yields in wet seasons in order to meet ever growing food needs and better the family's pocketbook and quality of life.
4. On newly deforested lands, the above needs may be met through the first two or three years, after which the situation lapses into what may be termed "1-ton agriculture", in which excess fertility (nitrogen mostly) has been tapped out. Crops thereafter must rely on nature's rate of nitrogen regeneration, typically allowing an average seasonal yield of basic food grains somewhere around 1,000 kg/ha. This yield can be attained in all but the very driest seasons because nitrogen, not water, is the limiting factor. It follows that yields are similarly limited in wetter seasons, erasing all hope of escaping poverty. With continuing low yields, soil organic matter - the stuff of good soil tilth - steadily declines. The soil becomes less workable, internal drainage and aeration suffer, and yields spiral still further downward, finally becoming untenable.

 The Fundamental Problem

 Seasonal rainfall in monsoonal regimes is notorious for variability and uncertainty, and our science has not been able to cope with the latter. In plain language, we have not been able to say, with any useful degree of certainty, whether the coming cropping season will be relatively wet or relatively dry, or essentially "normal". Until we develop this capability, sustainability of low resource farms/farm families in place is out of the question; slashing & burning new areas of natural vegetation, destroying wildlife habitat, will continue to be their only hope for survival.

 There are important differences in the agronomics which must be practiced in wetter versus drier seasons, if the essentials for sustainability are to be met. So called subsistence farming is the usual mode of operation today because it minimizes total crop failure rates and out of pocket costs. Aiming at higher yields is costly, requires different mixes of crops, new varieties, different tillage, row spacings and plant numbers, etc., and increases the crop failure rate in drier seasons. For example, poor peasant farmers have no money to buy fertilizers, and most would not dare, even though some increase in soil fertility might help stabilize their present subsistence yield levels. To cover the cost they would require higher yields with some produce to sell, which in turn requires changes in the farming system such as greater plant populations, switching to longer maturity varieties, or even to more desirable crops, all of which increase crop water requirements and the risk of complete crop failure if rainfall does not oblige. Production credit to purchase fertilizers and other inputs is not available for the same reason - the risk is too great.

 But credit would become available, and farmers would dare to make changes such as those suggested, if lenders and farmers could be assured (at a high level of certainty) that the coming rainfall season would not be a dry one, e.g. it would be in the normal to wet range, compared to all seasons. Conversely, if the forecast for the coming season were rains in the normal to dry range, they would benefit by aiming their decisions at a moderate to subsistence yield level, thus avoiding high costs and increased risk of crop failure.

 Paradoxically, peasant farmers in India, West Africa and elsewhere, for centuries have understood how to effectively reduce uncertainty about rainfall in the coming season, based on the date of onset. Generally speaking (and there are exceptions requiring special study), normal to wet seasons begin relatively early, while normal to dry seasons tend to start later. Noting this, peasant farmers have traditionally altered some management decisions from season to season to conform with projected rainfall - but with limited success. Agricultural scientists by and large have actually taken a step backward to the more conservative concept of a fixed "best bet" cropping system for use in all seasons in any given rainfall zone. However, in defense of our scientists, little else could be done prior to the advent of desktop computers capable of massive data storage, retrieval and analysis. The result is that slash & burn agriculture continues unabated at this time.

 In summary, rainfall variability calls for seasonal flexibility in emphasis on crops, inputs and practices, including tillage measures, with those used to establish crops in wetter seasons differing from those applicable in drier seasons. But uncertainty about expected rainfall in each budding new season leaves both farmers and their advisors without helpful seasonal guidelines.

The Solution, and Desperately Needed Action

 The solution lies with desktop computers and the perfect memory inherant in long term daily rainfall records - the worlds most extensive, most valuable, and most unused data base, which today largely molders away in pest infested back rooms of aging government buildings the world over, totally vulnerable to destruction by warfare, fire, natural disasters and other causes. Now, for the first time in the history of humankind, we have both the detailed data we need and the computers which can easily handle them. Should the daily rainfall histories so painstakingly gathered worldwide over the past two centuries be allowed to perish (and some do every day), our only presently known avenue for seasonal rainfall prediction is irredeemingly lost. Slash & burn agriculture will reign on, menacing humankind and the planetary ecolology.

 Some - those who initiated rainfall data collections when computer power was scarce, argue that representations of daily rain data statistically respun from decadal or even monthly summaries are adequate to the task, but that is not true - only the actual data are. And neither human memory nor personal experience nor statistical packages adequately deal with climate changes such as the abrupt drop in rainfall throughout the African Sahel in 1968. The only clear solution is to feed the original daily data into a computer, then ask the right questions. Only then will history speak and the correct answers appear.

 Low resource farmers are not positioned to keep up with the ever growing body of scientific knowledge available to guide them in making seasonal adaptations in their cropping systems, once expected rainfall conditions become known with more certainty. But agricultural scientists and extension agronomists are. And with todays rapid pace of development of computerized models and expert systems which emulate crop growth and yield responses to different management decisions, these answers too will be correct. Then monsoon nurtured agriculture will become sustainable with greatly lessened rates of crop failure and much increased overall production. The soil will stay in place and be upgraded. Slash & burn will disappear. The natural vegetation will flourish, as will the wildlife it shelters.

Developments Toward True Sustainability on Tropical Smallholdings: Recent History

While leading a long term project to develop cropping systems for low resource farmers in Kenya - just as a new age was dawning for desktop computers and essential database and spreadsheet software - Dr Stewart observed that early onset of the rains is better, and performed calculations for one key location in the project area. The analyses, carried out in 1980 with a hand calculator, took three months. They successfully established quantitative season prediction criteria, critical "onset" dates after which changes in management procedures should be invoked, and details of agronomic advice for both Plan A (early onset) and a modified Plan B (late onset). The prediction criteria and agronomic responses were then verified in 32 farmers' fields through four successive growing seasons in which rains ranged from excellent to terrible. The new methodology is termed "Response Farming"

 Upon project termination in Dec, 1983, Dr Stewart returned home to Davis, California, and together with colleagues, established WHARF. Meanwhile, Australian and Kenyan scientists, in a follow-on project utilizing sophisticated computerized crop models, have independently confirmed the 1980 findings, presenting their own in an international symposium in Brisbane, Australia in 1990

 Additionally, other respected scientists in India, West Africa and the USA have successfully carried out feasibility studies for response farming in many locations, plus actual field research and on-farm practice in West Africa (ICRISAT). WHARF publications, international presentations and consultancies have inspired graduate degree research projects at universities in the USA and Australia, and incorporation of response farming into USAID funded development projects in India, Jordan and Sri Lanka

 Throughout, WHARF has continuously engaged in (i) global rainfall data bank building, (ii) development of new and unique computer algorithms to determine narrowed bands of rainfall probabilities which relate directly to actual dates of rainfall onset and crop seed germination, and to the growing periods of individual crops, rather than fixed calendar periods, (iii) refinement of agronomic advisories to guide farmers in responding to rainfall forecasts, (iv) feasibility studies for response farming in new locations, and (v) presentation and publication of findings

 Also throughout, the computer hardware/software industry has built toward the present capability which enables any researcher to store and crunch almost limitless amounts of historical daily rainfall data in search of predictors for season rainfall, and for details of its behavior patterns as they affect crop water use, growth and yield, and equally, allows each field farm advisor to analyse the beginning rainfall events in each budding new season, and advise his farmer clients of their rainfall expectations in the coming season, and the steps they should be taking

 Now: The moment has arrived to gather the world's daily rainfall records, upgrade the computer modelling efforts of WHARF and other scientists, and establish pilot projects to test and demonstrate the effectiveness of response farming in making tropical smallholdings truly sustainable

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