Selasa, 20 September 2011

Investing in agriculture

For most people the idea of investing in agriculture conjures the images of extending credit to farmers or building new irrigation schemes but the most important investments needed to assure high agricultural productivity are in maintaining viable agroecosys-tems. Although modern agriculture has eliminated many environmental limits and insulated itself from many environmental interferences through fertilization, irrigation, use of pesticides and breeding of better cultivars, crop production remains embedded within the dynamic complexities of the living biosphere and depends critically on reli-able provision of many natural services and on the maintenance of essential ecosystem structures. These necessities range from having sufficiently friable soils containing large amounts of organic matter and protected against excessive erosion to promoting practices that will minimize nutrient losses from fertilizer applications and increase water use efficiencies in irrigation as much as practicable.
 Achieving these goals is a matter of complex management that can be effective only when we use the best understanding of how agroecosystems operate. For example, the first necessity (maintaining desirable soil structure) requires the use of appropri-ate tillage methods (including minimum tillage practices), recycling of crop residues and animal wastes, regular crop rotations, and where possible also planting of legu-minous cover crops (Agassi, 1995). Without these measures soil bacteria and inverte-brates could not thrive, high organic matter content able to maintain soil structure would decline, soil would not be able to hold moisture and would be prone to erosion losses that would eventually lower its productivity. Similarly, reducing nutrient losses requires measures ranging from repeated soil and plant testing and split applications of fertilizers to selecting appropriate cultivars and regular planting of cover crops (Smil, 2001). These practices require a great deal of understanding and ongoing per-sonal commitment by individual farmers but most of them now rest on fairly well-understood principles.
 In contrast, new methods of more productive farming will require further inten-sification of agricultural research and technical innovation. Not surprisingly, many observers of the current agricultural situation argue for substantially increased public support of basic and applied agricultural research (Pinstrup-Andersen, 2001), and there is no shortage of studies to show the efficacy of this approach. For example, Huang and Rozelle (1996) showed that innovation accounted for almost all of the growth in agricultural productivity in China during the latter half of the 1980s and in the early 1990s. Avery (1997) stressed that only further intensification of crop produc-tion can save the remaining tropical rainforests, and hence most of the world’s existing biodiversity, from eventual destruction. Virtually every assessment of future agricul-tural needs prepared by the FAO or by specialized crop research centers (International Maize and Wheat Improvement Center, International Rice Research Institute) notes that returns to public investments in agricultural research and extension are very high and urges that future funding should be increased. In spite of this well-proven reality research funding remains inadequate throughout the developing world.
Given this state of affairs it is even more worrisome that the developing world may not be able to take full benefit of one of the most important scientific advances of the past generation, our increasingly effective ability to confer desirable traits on plants and animals by means of genetic engineering. Of course, an argument could be made that the rich countries, with their obscene surplus of food, have really no need to use arcane techniques in order to further boost their crop and animal production. But a common view that genetic engineering is a tool of multinational companies geared toward the rich world’s markets and that developing countries have no chance to benefit from biotechnology is wrong. As Wambugu (2001) argues, small-scale farmers have profited by using hybrid seeds and transgenic seeds simply add more value to these hybrids.
This is a very important point that needs constant stressing to scientifically illiterate critics. All but a few of our currently planted crops are products of extensive breeding modifications and today’s world could not feed itself without using these hybrid and high-yielding cultivars. Traditional breeding has made a fundamental difference to the agricultural productivity of the 20th century; current harvests would be impossible without hybrid corn (introduced in the 1930s), HYV of rice and wheat (first released during the 1960s) and hybrid rice (developed in China during the 1970s). Hybrid corn, the planting of which began slowly in Iowa in the early 1930s, has transformed US corn harvests since World War II and is now benefiting both small- and large-scale corn producers throughout the developing world. Hybrid rice, which can boost aver- age yields by 15–20%, has been finally adapted to tropical climates and is now being accepted throughout Asia (Virmani et al., 1996).
Genetic engineering is thus only the latest, and the most powerful, tool of agricultural innovation. Admittedly, it is also a tool with considerable potential for adverse effects and unwanted complications but this reality should not be the reason for banning the  effort and walking away from the prospect of immense future benefits. After all, this combination of risks and benefits is nothing unique to genetic engineering. Modern society constantly confronts such dilemmas and has found ways to deal with them. Perhaps the most apposite example is that of drug companies and the billions of users of prescription medicines who must weigh the benefits against a range of potentially even fatal side effects. Careful research and testing and responsible regulation are the answers, not a ban on the drugs. Genetic engineering alone will not solve food short- ages that are now experienced by hundreds of millions of people but it could become the most powerful tool in that quest.
I will note just a few of the recent bioengineering advances whose potential for producing larger and better harvests or more desirable animals is self-evident. Broader-leafed rice can deprive weeds of sunlight, thus reducing the need for apply-ing herbicides or for laborious weeding. Rice with higher vitamin A and iron content can be the most cost-effective, as well as the most practical, way to end two of the most persistent micronutrient deficiencies in rice-eating countries. Millions of poor tropical families cultivating sweet potatoes in their fields and kitchen gardens would benefit from a transgenic cultivar resistant to feathery mottle virus which can reduce the yields by up to 80% (Wambugu, 2001). And, to give perhaps the most impressive example from animal farming, transgenic pigs able to produce phytase (the enzyme needed to digest phytate phosphorus in their feed) in their saliva will void manure with phosphorus content reduced by up to 75% (Goloran et al., 2001). This impres- sive achievement will reduce one of the principal causes of aquatic eutrophication, algal growth and fish kills in affected waters.
Seeing genetic engineering as the solution to the world’s food problems would be na├»ve. Refusing to proceed with careful research and regulated applications might be one of the most shortsighted human choices ever made as the technique has potential not only for increased and improved food production but also for enhanced environ-mental protection. Well-conceived bioengineering research, together with the stress on environmentally sound farming and higher efficiency in the use of all farm inputs, should be one of the key ingredients with which to build greater food security for tomorrow’s developing world.


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