Oferta de serviços ambientais na agricultura

Abstract

1. Agricultura sustentável 2. Poluição ambiental 3. Recursos hídricos I. Título CDD 630.2745 "Permitida a cópia total ou parcial deste documento, desde que citada a fonte-O autor" ABSTRACT Supply of Environmental Services from Agriculture Water erosion is the main cause of soil degradation in tropical and subtropical environments and top soil loss is the biggest challenge for sustainable agriculture in the world. It affects water quality and quantity, and decreases soil quality. Despite this, the market is not able to solve these problems because of their public good characteristics (non-rivalness and non-excludability). Agricultural pollution control by farmers is a service society free rides because only farmers pay its costs. Payments for Environmental Services-PES schemes are flexible mechanisms in which providers of these services get paid by their users. PES schemes are considered to be promising mechanisms for financing environmental protection and restoration as well as for complementing and enforcing regulations. However, most of the ongoing schemes don't use studies to quantify the services produced, to analyze the demand for them, or to check the schemes' economic viability. This study analyses the economic viability of PES schemes in order to control the agricultural pollution of water resources in Brazil. The specific objective is to estimate the Environmental Services-ES of conservation soil supplies. These supplies were estimated for sugar cane (Corumbataí Watershed) and horticulture areas (Tietê Cabeceiras Subwatershed), using a minimum-data model. The supplies were calculated for different practices, so it is possible to compare the different practices' efficiency to produce ES. For the sugar cane area it is more efficient to plant trees in the riparian buffer zones. Paying 150 reais per ha per year produces 140.000 Mg of conserved soil through tree planting, while with the same amount, the exclusion of the riparian zones from cultivation produces approximately 70.000 Mg. The results show this model can be applied as a way of integrating agricultural and environmental public policies. It was concluded that incentives are necessary to make the farmers adopt the practices that produce ES, because they are not economically feasible under current market conditions. The incentives could be either subsidies for these practices, fostering the demand for environmental friendly products, or direct payments for the ES produced.