|“I dare say that around year 2010, there will be a tremendous quantity of basic grain - rice, maize, sorghum, soy and pulse - to be exported to diverse countries of the world that will be produced on the cerrado.” “I had never believed that I would live to see technology developed which would convert these vast areas of well-watered but infertile land from the unproductive natural vegetation of grass and bush to highly productive agricultural land.” “I am convinced that what is happening on the cerrado is one of the most spectacular event in agricultural development that has been accomplished in the world over the last hundred years.” (1995)***
The Brazilian Cerrado
The potential for further expansion in the global arable land area is limited for most regions of the world. This is certainly true for densely populated Asia and Europe. Only in SSA and South America do large unexploited tracts exist, and only some of this land should eventually come into agricultural production. In populous Asia, home to more than half of the world’s people, there is very little uncultivated land left. Indeed, some of the land, especially in South Asia, currently in production should be taken out of cultivation, because of high susceptibility to soil erosion.
Bringing the world’s unexploited potentially arable lands into agricultural production poses formidable challenges. The Brazilian Cerrado, or acid savanna, is a good case in point. The Cerrado is a vast expanse of mostly flat to slightly rolling grasslands, with fire-induced semi-climax brush and stunted-tree ecotypes in some areas. Its total area is approximately 205 million ha, approximately equivalent to the combined area of Spain, France, Italy and Britain. It spans a geographic area from latitude 24° to 4° S and varies in elevation from 500 m to 1,800 m, with unimodal precipitation (October to March) varying from 900 to 1,800 mm annually (see map).
The central Cerrado, with 175 million ha in one contiguous block, forms the bulk of the savanna lands. Approximately 112 million ha of this block is considered potentially arable. Most of the remainder has potential value for forest plantations and improved pastures for animal production. The soils of this area are mostly various types of deep loam to clay-loam latosols (oxisols, ultisols), with good physical properties, but highly leached of nutrients. They are strongly acidic, have toxic levels of soluble aluminum (and of manganese in some areas); most of the phosphate is fixed and unavailable.
Until 50 years ago, the Cerrado was sparsely inhabited and considered to be essentially worthless for agriculture. Some agriculture was practiced on strips of alluvial soils along the margins of streams, which were less acidic and where there had been an accumulation of nutrients. In addition, there was some cattle production, but the natural savanna/brush flora (poor digestibility and nutritive quality) resulted in low carrying-capacity production.
Today, a great agricultural revolution is under way in the Cerrado, the result of a long process of research and development. Bits and pieces of research information on soils and agronomy and some aluminum-tolerant plant germplasm were developed during the 1930s and 1940s at various agricultural universities and provincial and federal government experiment stations (1). By the late 1960s, farming was being attempted in some parts of the Cerrado on a commercial scale as soil amendments began to be applied—liming to correct acidity and aluminum toxicity, combined with NPK, sulfur, and micronutrient fertilizers. A new generation of crop varieties (forage grasses, rice, soybean, maize, and wheat) was developed that possessed tolerance to aluminum toxicity. Unfortunately, this first group of varieties, although tolerant to aluminum toxicity, had low grain yield potential and other defects, especially susceptibility to various diseases.
The creation in 1973 of the Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)—the national Brazilian Agricultural Research Corporation—provided a significant impetus to research aimed at the Cerrado. EMBRAPA scientists initiated a systematic program of interdisciplinary research, integrating past knowledge and generating new research information and products. Much of the soil fertility/ toxicity research and interdisciplinary agronomic research was centered at the Centro de Pesquisa Agropecuária del Cerrado (CPAC), located near Brasilia, while the research on breeding of improved crop varieties with disease and insect resistance was carried out at various EMBRAPA commodity-specific national research centers.
During the 1980s, EMBRAPA and several international agricultural research centers (especially CIMMYT and CIAT) began more intensive collaboration to develop a third generation of crop varieties combining tolerance to aluminum toxicity with high yield, better resistance to primary diseases, and better agronomic type. There are good varieties with aluminum tolerance in the case of rice, maize, soybeans, wheat and several species of pasture grasses, including panicums, pangola, and vaqueria. Triticale is an interesting man-made cereal that has a very high level of tolerance to aluminum.
However, up to the present time, it has not been widely used in the Cerrado, either for forage or for grain production. There are many research challenges in the present situation of commercial crop production in the Cerrado that are still unfolding. Many advances are being made by farmer associations, both alone and in collaboration with scientists.
Much more needs to be done and more research is needed, both by public and private sector organizations. Further research is needed to develop the more exact fertilizer recommendations for different crops in the different areas. Since the zero tillage or minimum tillage is in widespread use, whereby the plant refuse or plant residue is left on the surface, it will be absolutely necessary to work out better crop rotations to minimize the foliar infection with diseases that result from inoculums remaining in the plant crop residue from the previous season or two.
Huge investments are being made to develop transport systems from the Cerrados to the ocean-going ports. Roads, railroads and barge systems will soon link much of the Cerrados to ports and greatly reduce transport costs, which has been a major obstacle to full economic development.
If the improved technology currently available was used now on the 20 million ha of potentially arable rainfed land in the Cerrado, it would be possible for farmers to attain 3.2 tons/ha average yield and 64 million tons of production. The irrigated area could also be increased tenfold—to 5 million ha—with an expected average yield of 6 tons/ha, for a total crop production of 30 million tons. The meat production could also be increased fourfold with improved pastures. In total, food production could be tripled, from the 30 million tons today to nearly 100 million tons, through widespread adoption of improved technology already available (Table 5).
The opening of the Cerrado will help ensure adequacy in world food supply for the next two decades if we continue to use wise policies to stimulate production. Eventually, the technology similar to what made the Cerrados productive will move into the llanos in Colombia and Venezuela and hopefully into central and southern African countries where they have similar soil problems.
Table 5. Potential Food Production if Technology Available in 1995 Is Adopted on Cerrado Area Already in Production
........................................(million ha).................t/ha/year................(million tons)
Source: J. Macedo, CPAC, EMBRAPA,1995
Thirty-three years ago in my acceptance speech for the Nobel Peace Prize, I said that the Green Revolution had won a temporary success in man’s war against hunger, which, if fully implemented, could provide sufficient food for humankind through the end of the 20th century. This has happened. But I also warned that unless the frightening power of human reproduction was curbed, the success of the Green Revolution would only be ephemeral.
I now say that the world has the technology—either available or well advanced in the research pipeline— to feed a population of 10 billion people. Improvements in crop productivity can be made all along the line—in tillage, water use, fertilization, weed and pest control, and harvesting. Both conventional breeding and biotechnology research will be needed to ensure that the genetic improvement of food crops continues at a pace sufficient to meet growing world populations.
The more pertinent question today is whether farmers and ranchers will be permitted to use this new technology. Extremists in the environmental movement from the rich nations seem to be doing everything they can to stop scientific progress in its tracks. Small, vociferous, highly effective and wellfunded anti-science and technology groups are slowing the application of new technology, whether it be developed from biotechnology or more conventional methods of agricultural science.
Only around 4% of the population in industrialized countries (less than 2% in the United States) is directly engaged in agriculture. With low-cost food supplies and urban bias, is it any wonder that consumers don’t understand the complexities of reproducing the world food supply each year in its entirety and expanding it further for the 80 million additional people that are added annually. I believe we must seek to redress this “educational gap” in industrialized urban nations by making it compulsory in secondary schools and universities for students to take courses on biology and science and technology policy.
In conclusion, permit me to leave you with this thought, so eloquently expressed by Andre and Jean Mayer, two American nutritionists, in an article, Agriculture—The Island Empire, published in 1974 in the journal Daedulus of the American Academy of Arts and Sciences:
“Few scientists think of agriculture as the chief or the model science. Many, indeed, do not consider it a science at all. Yet it was the first science—the mother of all sciences; it remains the science that makes human life possible; and it may well be that, before the century is over, the success or failure of science as a whole will be judged by the success or failure of agriculture.”
(*) Publication (23 pages, 2003) of the International Fertilizer Development Center - IFDC, Muscle Shoals - AL, USA.
(**) Father of the Green Revolution-1968; Nobel Peace Prize-1970; Presidential Medal of Liberty (USA)-1977; Congressional Gold Medal (USA)-2006; Professor of Agriculture History at Texas A&M University (USA).
(***) Excerpts of letters to one of his Brazilian friends.
(1) Including research by IRI - Intl. Research Inst. (Rockfeller Brothers), Matão-SP, BR, (1954/64), showing that poor cerrado soils could produce as well as tall forest rich soil provided it is duly limed and fertilized, even without animal manure.
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