http://lattes.cnpq.br/0397018602691260; FRANCO, Euler Soares.
Resumo:
In the semi-arid regions the environmental degradation is resulted of several factors, such as:
climatic variations, lost of the vegetation covering and other atrophic activities. In the Brazil
Northeast Region, where is located the Caatinga biome, which is the one that suffer so much
because of these factors. The most part of the vegetation covering of this region is composed
by caatinga and nowadays the most part of it is formed by Prosopis. It was brought to Brazil
in the 40s, after that arrives in the Northeast in Serra Talhada city in Pernambuco, in the
middle of 1970, the government stimulates farmers to take out caatinga native vegetation and
substitute it by Prosopis because it was always green and could be used for everything.
However, by the years, it did not stimulate the farmers anymore and the plant that came to
minimize the problems during the dry period in the region is now considered a problem. To
make clear the social-environmental questions about Prosopis the research was divided in two
parts: in the first one it was carried out a research in the cities of Boqueirão, Cabaceiras e São
João do Cariri, in Paraiba State Brazil, where it was interviewed 306 farmers, 102 in each
city; the second one was carried out in a place located at the Campina Grande Federal
University with the objective to evaluate Prosopis hydric consumption thought the
replacement of évapotranspiration fraction, fresh water, it was adopted five water depth levels
(20, 40, 60, 80, 100), height of plant, stem diameter and root length were also evaluated,
according to évapotranspiration levels. The irrigations were done each three days. Interviews
with the farmers were made in which were observed that the highest incidence of Prosopis
were in the rural areas less than 5 ha and that it is used as animal ration and wood, this r is
used as energy resource such as cool and firewood. Considering that it was applied 17.165
liters of water during the research and that the évapotranspiration in the same period was
16.954 liters, the less value of évapotranspiration 138,54 liters was observed in the reposition
level T (20%) and the highest one was 863,86 liters at the level of T (100%). The height of
plant and steam diameter increased according to the increase of water level and according to
the time. The total productions of dry biomass was 36,05kg with water efficiency of 0,47
g/kg, gram of produced dry biomass to each kg of applied water. Of out 180,67 km
corresponding to the total length of root the biggest average was equal to 5575,15 m observed
in at water level T (60%). It was observed that the soil chemical composition analysis at the
end of the research were better when compared with the ones at the begin of the research, it
was observed reduction in the pH level and an increase in the levels of nitrogen and organic
matter.
