Composição, estrutura e função de quintais agroflorestais no município de Mazagão, Amapá.

Abstract

The migratory agriculture which is common in Amazon did not provide economic sustainability for local farmers. Besides of this, increasing demographic pressure has also been creating environmental problems. Then, the search for a new way of land use conquered more space, including the Agroforestry Systems (AFSs). The aim of this work was to evaluate agroforest homegardens in Mazagão municipality, Amapá. It was evaluated botanic composition, vertical and horizontal structure, self-provision, and income generation. According to Köppen classification Mazagão (0.1°N and 51.9°W) has a super-humid equatorial climate, classified as Ami. The mean minimum temperature is 23°C and the maximum one is 38°C. Annual precipitation is around 2,500mm. Most of the rains occur from January to July. Contacts were done with local people who had knowledge about farm activities in Mazagão in order to identify communities and properties to be visited. All properties had to fit in the agroforestry homegarden concept. This was the choice criterion for properties which would be studied. It was selected four properties, three in dry land and another one in a floodplain. In all properties interviews were done with farmers in order to know socioeconomic features. In the same sites botanic composition in the homegardens were evaluated. All plants were counted and some parts of the homegardens were selected for vertical and horizontal structure studies. Based in the productive plants found in the homegardens and their yield it was estimated the production of each homegarden. To estimate vitamins, proteins, and minerals availability, it was used a food composition table. From a daily person nutrient requirements it was calculated the nutrient needs for each property. The size of the homegardens varied from 3,510m2 to 8,260m2. The homegardens showed diversified botanic composition. From all kinds of plant groups, fruit plants had the highest species and individuals number. The Jaccard coefficient did not indicate high similarity among homegardens composition. The Shannon-Wiener diversity index showed significant differences among homegardens. However, it was higher than other related studies. The vertical structure was multistrafied with three main strata in three homegardens and with four strata in another one. The horizontal structure indicated that the coverage index had a variation among sites. It presented 0.6 to more than 1.5 of crown-soil area ratio. The homegardens provided all needs of potassium for dwellers all year long. Monthly human requirements of Vitamin C were also offered in most of the months. Variable quantities of Thymidine, Niacin, proteins, and minerals were avaliable during some months by found species in the homegardens. The homegardens represented 4.8% to 46.7% of the total family income. In the properties which there is earnings from wages or retirements, the homegarden contribution in the family income is much more lower.