Valoração econômica dos impactos ambientais de tecnologias de plantio em região de Cerrados

Abstract

A expansão da fronteira agrícola nos Cerrados com a produção agropecuária em larga escala amplia os custos ambientais, porém sua intensidade depende essencialmente da técnica de plantio adotada. O estudo valora economicamente, através do Método Custo-Reposição (MCR), os impactos ambientais de tecnologias de plantio de soja e milho em região de Cerrados. No caso da soja a adoção do plantio direto eleva o custo de produção em 0,47%, mas provoca uma redução de (- 81,22%) no custo ambiental. No cultivo do milho, os custos de produção do plantio direto são (- 5,92%) menores do que os referentes ao plantio convencional e provoca uma redução no custo ambiental em (- 29,43%). Na região específica do estudo os danos ambientais anuais causados pelo plantio convencional foram estimados em R$ 317.213,39 e no plantio direto de R$ 81.375,76. A adoção do plantio direto nas culturas de soja e milho demonstra sua maior eficácia social pela redução do processo erosivo dos solos e do assoreamento de recursos hídricos.<br>The expansion of the agricultural border in Brazilian savannahs with the farming production in wide scale extends the environmental costs; however it essentially depends on the adopted technique of plantation. The study evaluates economically by Replacement Cost Method the environmental impacts of technologies of soy and corn plantation. In the case of soy the no-tillage raises the cost of production by 0,47%, but it causes a reduction of (- 81,22%) in the environmental cost. As to corn, the costs of no-tillage are (- 5,92%) lower than conventional tillage and cause a reduction in the environmental cost by (- 29,43%). In the specific region of the study the annual environmental damages caused by conventional tillage had been estimated at R$ 317,213.39 and no-tillage of R$ 81.375,76. The adoption of no-tillage in the plantation of soy and corn demonstrates its bigger social effectiveness for the reduction of the erosive process and improvement of the outflow and quality of the rivers

The costs of soil erosion

“…For Marques, the market system is flawed, since most of the cost of soil erosion is borne by society. Rodrigues (2005) studied the costs of soil erosion by comparing no-tillage and conventional systems of soybean and maize in the Cerrado region. When used for producing soybean, the adoption of no-tillage raised production costs by 0.47 , but reduced soil erosion costs by 81.22 %.…”

“…Some authors calculated N and P losses (Stocking, 1988;Colacicco et al, 1989). Others also included K (Marques et al, 1961;Larson et al, 1983;Crosson, 1986;Troeh et al, 1991;Pimentel et al, 1995;Hein, 2007;Montanarella, 2007) and others, Mg and Ca (Sorrenson & Montoya, 1989;Martin et al, 1991;Marques, 1998;Rodrigues, 2005;Bertol et al, 2007;Sarcianelli et al, 2009). …”

“…In these studies, the authors normally used secondary data on soil, nutrient and yield losses to determine the average cost of erosion per hectare and, once these data were obtained, they extrapolated to the entire cultivable area of a given region (Bennett, 1933;Larson et al, 1983;Crosson, 1986;Stocking, 1986Stocking, , 1988Bishop & Allen, 1989;Colacicco et al, 1989;Troeh et al, 1991;Margulis, 1992;Bojö & Cassells, 1995;Pimentel et al, 1995;Pretty et al, 2000;Uri, 2000;Riksen & Graaff, 2001;Hansen et al, 2002;Cohen et al, 2006;Montanarella, 2007;Kuhlman et al, 2010). A significant limitation of these studies is that they often omit the regional Sorrenson & Montoya, 1989;Martin et al, 1991;Marques, 1998;Rodrigues, 2005;Bertol et al, 2007;Hein, 2007;Sarcinelli et al, 2009). Their studies are more accurate in methodological terms and take account of all USLE factors.…”

“…In Brazil, although soil conservation is a respected and well-established science, there are few studies on the costs of erosion, which are normally restricted to few soil types and regions (Marques et al, 1961;Silva et al, 1985;Sorrenson & Montoya, 1989;Derpsch et al, 1991;Marques, 1998;Rodrigues, 2005;Bertol et al, 2007;Sarcinelli et al, 2009). …”

Perdas e custos associados à erosão hídrica em função de taxas de cobertura do solo

“…In Brazil, the association of physical losses caused by erosion with their economic aspects is not new (Telles et al, 2013b), but this approach was considered in a few studies (Marques et al, 1961;Sorrenson & Montoya, 1989;Martin et al, 1991;Marques, 1998;Rodrigues, 2005;Bertol et al, 2007;Sarcinelli et al, 2009;Dantas & Monteiro, 2010;Pugliesi et al, 2011;Andrade et al, 2011). Although these have addressed only the losses of nutrients in the production unit (on-site), representing a small portion of the total costs of soil erosion (Crosson, 1995), this information is important for farmers, researchers and policy makers to form their opinions on the conservation management practices.…”