One of the highlights of the reforestation congress held in São Paulo last November was the presentation of the results of 26 years of field work by researchers from Colombia. Their research work focused on cattle raising in tree-covered pasture land, an agroforestry practice that is referred to as silvopastoral system. In Brazil, the silvopastoral system is still in its earliest stages. This system is very simple: the cattle, instead of lowering their heads under the hot sun to graze on pastureland, feed on the leaves and fruit from shrubs and trees planted in the middle of the pasture. As a result, cattle ranchers can raise up to five cows per hectare, producing an annual yield of 10 to 15 thousand liters of milk without the need to use fertilizers and hardly any dietary supplements. In contrast, cattle ranchers raising cattle on treeless pasture land raise one animal per hectare – the average in Brazil´s Amazon Region is even lower : 0.9 cattle per hectare, yielding 400 liters of milk a year per hectare. In addition, trees preserve springs, protect the soil from erosion, significantly reduce the population of disease-transmitting flies and ticks, reduce the costs of veterinary medicine, fertilizers, and pesticides, and recover part of the original biodiversity – destroyed by animal husbandry activities – thanks to the fact that they attract birds and other animals.
In Colombia, nearly two thousand farmers converted approximately 45 thousand hectares of degraded pasture land into tree-covered grazing land, the result of a partnership between the Colombian Federation of Cattle Raisers (Fedegan) and the Center for Research on Sustainable Systems in Farming and Animal Husbandry (Cipav), The Nature Conservancy (TNC) and the World Bank. Enrique Murgueitio Restrepo, director of Cipav, pioneered this effort by growing trees on pastural land after convincing rural landowners that leaves and fruit could be as nutritious for cattle as alfalfa and grass.
His arguments were convincing because at that time Colombia´s farmers were looking for alternatives to deal with the crisis in the sugar and coffee markets. The team from Cipav achieved good results, which led to the expansion of the silvopastoral system to farms in other countries, such as Bolivia, Guyana, Panama, Costa Rica, Nicaragua, Guatemala and Mexico and to partnerships with researchers from the U.S.´s Yale University.
The team of 40 researchers from Cipav is currently working to expand the area of forested pastural lands in Colombia to more than 45 thousand hectares, thanks to funding of US$ 7 million from the World Bank. According to Restrepo, this is the first step in an ambitious plan to convert 10 million hectares of existing pasture land. The effort is being led by the Colombian Federation of Cattle Raisers. In Colombia, pastural land takes up approximately 40 million hectares, “and the average deforestation rate in the period from 2005 to 2010 came to 285 thousand hectares, more than half of which was cleared for pastural land,” says Murgueitio.
“The main battle is in Brazil, and not in Colombia,” he states. He points out that in the State of Para alone 10 million hectares of degraded pasture land could be converted into forested pastural land to provide higher economic yields. In his opinion, maintaining four animals per hectare – and not only one, which is the average in Brazil – on an area of 100 hectares, with the same number of animals, would free 75 hectares for other farming activities. Extensive cattle raising, which entails an average of one head of cattle per hectare, is the predominant situation in Brazil. According to the farming and animal husbandry census of 2006, the latest census conducted by the Brazilian Institute of Geography and Statistics (IBGE), cattle ranching takes up nearly half (48%), or 158 million hectares, of the total farmland in Brazil, while farming takes up 59 million hectares. The total cattle herd, comprised of 206 million head of cattle, is bigger than the country´s population of 190 million people.
“We already have enough information to expand this technique all over Brazil,” says Ricardo Rodrigues, professor of the Luiz de Queiroz Higher School of Agriculture (Esalq) of the University of São Paulo (USP). “Degraded pasture lands could be reverted into forested pasture lands, thus resulting in environmental and economic benefits. This would be especially beneficial in areas no longer suitable for farming, where the terrain is at risk of causing erosion and landslides, such as the landslides that occurred recently in a certain mountainous region of Brazil.” This would be one way of increasing productivity and preventing erosion, which degrades treeless pastural land soil in 5 to 10 years.
In May and October, Rodrigues and Sergius Gandolfi, also from ESALQ, went to Colombia at the invitation of researchers from Yale University. In Colombia, they visited farms whose owners had been convinced by Murgueitio´s arguments. Accustomed to the landscape in Brazil, the two professors were amazed when they saw well-nourished cattle in the middle of forested land, grazing on the leaves of the leucena (Leucaena leucocephala) tree, which is considered as being an invasive species in Brazil. They also did not expect to see hedges instead of fences, as is the case in Brazil. “The advantage of hedges is that they do not rot and do need to be replaced,” says Gandolfi. “They can also be a source of income, as farmers can trim the branches and sell the wood to make charcoal.” Trees also reduce the temperature by two to three degrees, thus creating an agreeable environment for the cattle.
In 2009, when they were interviewing farmers from the region of Quindío, Colombia, Alicia Calle and Florencia Montagnin, of Yale University´s School of Forestry and Environmental Studies, noticed that the gliricidia (Gliricidia sepium) tree was the tree of choice for hedges because it grows quickly and provides shade for the cattle. The researchers noticed that the seedlings of this tree species had been recently planted along a five-kilometer perimeter surrounding the pastural land of the farms they were touring.
Progress and resistance
A number of studies conducted in Brazil in the last few years, especially by researchers from the Brazilian Agricultural Research Corporation (Embrapa), highlight the benefits of forested pastural lands, in comparison with conventional pastural land: the lack of shade, for example, can reduce dairy cattle milk yields by 20%. A nationwide survey, conducted by Jorge Ribaski, of Embrapa Florestas, headquartered in the city of Colombo, State of Paraná, registered an increase in forested pastural lands, generally in areas where the soil is more susceptible to erosion. In the northeast region of the State of Parana, the need to have feed for the cattle during winter – when grass becomes scarce – motivated 200 cattle ranchers to let trees grow on approximately 7 thousand hectares of pastural land.
ANA PAULA CAMPOSWeight gain has been easy to show. Ribaski noticed that calves can weigh up to 450 kilograms in 60 months when raised on pastural land in the caatinga (shrub land) region in Brazil´s Northeast. In contrast, calves raised under traditional methods weigh an average of 360 kilograms in 54 months. According to Ribaski, and based on the results of this survey, the Secretary of Agriculture of the city of Alegrete, in the State of Rio Grande do Sul, built a nursery capable of producing 350 thousand tree seedlings to be given out to farmers from the region. This region is undergoing a continuous advance of sandy soil on the farm lands.
However, there is some resistance, as the adoption of a given technology does not depend only on technical arguments. Biodiversity and cattle comfort-related gains are not enough to convince cattle breeders. Moacyr Dias Filho and Joice Ferreira, researchers from Embrapa Amazônia Oriental, in the city of Belém, State of Pará, observed that the farmers who can benefit from the silvopastoral system are usually found in regions with an abundance of farmland for agricultural expansion; as a result, they are not highly motivated to implement new methods. In addition, farmers complain that the benefits are long-term ones, while the raising and planting of seedlings and farm labor entail short-term costs. Another barrier is the risk of accidental fire, which can burn everything down – thus entailing more expenses.
Nevertheless, some results can already be seen. Researchers from Embrapa Sudeste have already selected the most appropriate native trees for the cattle to graze under. In addition, they are following the experimental implementation at farms in the regions around Brotas, Ibirá, Olímpia, Aspásia, Riolândia and Votuporanga. The Colombian experience, especially in relation to the techniques to convince potential users, can be very useful. “Most cattle ranchers do not trust technicians or scientists,” says Murgueitio. “They only accept what other ranchers have already done.”
The pequi and surfers
In Brazil, Rodrigues points out, 20% of the total area of a rural property in the Southeast and 80% in the North are obliged to be covered in native vegetation, according to the forestry code. These lands can be used in a sustainable manner for production. “Very few rural landowners are aware of the possibilities of using these forests on such legally conserved land sustainably, as they are usually viewed as being untouchable,” he says. To demonstrate this possibility, Rodrigues and his team are following the planting of native trees for economic purposes. These trees will be cut down with legal permission in the course of 40 years, in 12-year cycles. The trees are being planted on a 300-hectare area in the municipal region of Campinas.
In 2011, Ana Claudia Sant’Anna, of Esalq, compared the income obtained from collecting the native fruit of the pequi (Caryocar brasiliense), a native fruit from the Brazilian cerrado (tropical savanna) widely used in regional cuisine, with the income obtained from the cultivation of soy beans in the regions of Iporá, State of Goiás, and Pirapora, State of Minas Gerais. The conclusion was that the sustainable extract of at least 10 pequi trees growing on the legally protected lands in the cerrado can be as profitable – or even more profitable – than the production of soy beans. This research study is another argument to convince farmers that these legally protected lands are not untouchable.
“The coexistence of land for production and land for conservation is not incompatible,” Gandolfi said at the reforestation symposium held in São Paulo. In one of his classes of the agronomy course held at Esalq in 2011, Gandolfi told students the story of two American surfers who had come to Rio de Janeiro to enjoy the waves. They were enchanted by the assai (Euterpe oleracea). When they got back to California, they partnered with two other surfers to start a company that sells the juice of the Brazilian assai to athletes in the United States. At the end of the class, Gandolfi asked his students whey they didn´t imitate the surfers and create a million-dollar business to take advantage of the immense wealth found in Brazilian forests.
CALLE, A. et al. Farmer’s perceptions of silvopastoral system promotion in Quindío, Colombia. Bois et Forêts des Tropiques. v. 300, n. 2, p. 79-94. 2009.
MURGUEITIO, E. et al. Native trees and shrubs for the productive rehabilitation of tropical cattle ranching lands. Forest Ecology and Management. v. 261, n. 10, p. 1654-63. 2011.