Avaliação agronômica de sistemas agroflorestais no Município de Eldorado do Carajás, Pará

Abstract

In front of necessity of news practices and governments political of incentive to the regaining of the Agroforestry Systems (ASs), are appointed as promising option to propose variation of the productive activities and return the agro ranching activity less ecological damage. The absence of study about value of portion of ASs has limited a better reflection about the efficiency of this systems about the sustainability of the agroecosystems in the context of the family farm, in especial in the Amazon space. In the perspective, the present study proposed an agronomic evaluation in portions of ASs introduced in the Settlement Project Eldorado and Moça Bonita in the city of Eldorado do Carajás, territory southwest from the Pará state. The sample used was constituted by three portions of ASs: AS-1 and AS-5, in the settlement Moça Bonita and AS-2 in the settlement Eldorado. The methodology consisted in the construction of a square of agronomics indicators, referents to the dimension technical economical (biophysical, vegetable population, technical management) of the portion of Agroforestry System. The survey of the indicators was with interviews realized in locu, consults in theories references, visual evaluation of the areas of pasture besides of the portions of ASs, collection of soil, contain of the numbers of individuals and the species (exotics and natives), measure of the Diameter to the Height of the Chest (DHC), the total height (m), commercial height (m), Canopy diameter of the top (m) of the forest species in the three portion of ASs during dry station (july) and raining station (november). To the visual evaluation was plicate a sampling of 40 m2 situated in open pasture. The samples of soil were collected in depth of 0-20, 20-40 and 40-60 cm, the tens first points were located in the areas more below of the portions, and the tens last points were collected in areas of declivities in the land rights. The point of view of the agronomic evaluation, was contacted a series of limitations on the portions of ASs. In relation to the biophysical, all the ASs presented limitations related with declivity, deficient drainage, absence of water in the soil and stoniness and climates questions, the AS-2 was the that presented more limitations. About the aspects related the vegetable population, the ASs presented low level of diversity, with little or neither fructiferous species predominating commercials species, with low level of regulation in the family agroecosystem. In the face this aspects the AS-5 was the more fragile, presenting low levels of biomass and carbon stock. About the management of the ASs, was verified little or neither one experience with ASs and little technical monitoring, low capacity of investment and restriction of man power. Just the agroecosystem with the AS-2, showed interest in investing in ASs with a strong element of variation, although the AS-1 has been stand out as an interesting experience, the agroecosystem AS-1 and AS-2 are abandoning the adoption of sustainable alternatives to maintain a dynamics of specialization in livestock, affecting straight the sustainability of this ASs. The diagnostic pointed out the necessity of improvements in the process of introduction of ASs in these settlements.