Efeitos de intervenções técnico-produtivas para a sustentabilidade do uso da terra em agroecossistemas familiares no território do Baixo Tocantins, PA

Abstract

The study deals with the sustainability of land use in family agroecosystems located in the municipalities of Cametá (communities Ajó and Inacha) and Moju (PA Calmaria II, communities of São José and Água Preta), belonging to the territory of Low Tocantins, state of PA, proposing to compare the main effects resulting from two modes of interventions in the technical-productive systems. The two interventions were established proposing innovations and improvements for sustainable development, the first in Cametá, promoted by "networks of multiplier farmers" with proposals for agroecological use and management and the second in Moju refers to programs to encourage palm oil plantation.The main focus of the study is based on the following questions: what are the main effects on sustainability that the innovations in land management and sustainable development introduced by the National Program for the Production and Use of Biodiesel (PNPB) on the one hand and Networks of multiplier farmers, with agroecological management proposals on the other, lead to family agroecosystems? Have these interventions provided improvements with sustainability? The research hypothesis suggests that the technical-productive innovations promoted in family agroecosystems by the multiplier farmers are more sustainable. The general objective is to analyze the main effects of technical-productive interventions in land use, on the sustainability of family agro-ecosystems. The specific objectives are to verify if the interventions provided improvements with socio-environmental quality; to evaluate comparatively the quality of the soil in systems of use of familiar agro-ecosystems, that had differentiated technical-productive interventions; and to distinguish the main modes of use practiced in the familiar agroecosystems in order to elucidate their relations with the biophysical environment and with the different ways of managing the fertility of the environment. For the development of other companies in other regions in Cametá: Caripi, with dry land ecosystem and Cupijó, with dry land ecosystems and floodplains. The methodological procedures used were surveys with semi-structured forms and description and soil collect for laboratory analysis. The results obtained from four dimensions indicators of sustainability showed that the interventions, to a certain extent, reached the objectives, but many problems were observed, such as those that reflect a relationship between farmers and technicians, that still can not surpass the conception of "transmission of knowledge and technology", in the case of the intervention in Calmaria II. In the communities of Ajó and Inacha, the most determining reasons for some differences would be the assiduity and intensity of technical assistance attributed more to Ajó; The fact that these family agroecosystems have availability of a diversified biophysical environment (dry land and foodplain), allowing greater variation in production systems; and the consequent reduction of the use of fire. In the communities of São José and Água Preta the most significant cause of the distinctions between them would be that São José has a higher income, due to the period of the palm harvest, which coincides with that of the Água Preta (neighboring community to the large palm oil plantations. This fact guarantees a better price of the production to São José. This difference in the harvest and off-season months would be related to the water supply, available to the culture in São José, during the rainy season, caused the main differences between the two types of agro-ecosystems are that they do not have the same characteristics as the biophysical environment, and that there are different levels of satisfaction with the oil palm. Environment are determined by the management of the fertility of the environment of each one, constituting the differentiation between the production systems in each specific environment. The data indicated that, according to the environments, farmers take advantage of the different potentialities of use, adapting the ways of managing the fertility of the natural environment. The soil attributes that were considered significant to evaluate sustainability indicate that the land uses studied presented little expressive differences. The biophysical environment was determinant for some types to stand out positively. By the pedological analysis of Ajó locality (SAF) it is noticeable that their soils are more naturally enriched in exchangeable bases (K+ , Ca2+, Mg2+). In São José, some physical factors are better, because the soils retain water for a longer time, making this available to the palm oil tree for a longer period in the dry season.