Respostas de mudas de Gliricidia sepium à aplicação de nitrogênio e fósforo.

Abstract

The fast growth of the world population took to the need of great increments of the agricultural production with actions that can take ecosystems to states of disturbances happening continuous loss of the productivity biological or economical and of the complexity of the agricultural lands. The main causes of the degradation of those arid and semi-arid areas are the excessive use or use inadequed of the resources of the earth worsened by the droughts. The search for alternative technological applicable and compatible with the ecological particularities of each plot. Several techniques of recovery of degraded areas exist, a quite used is the implantation of species of fast growth, multiple use, resistant to cultural treatments and the climatic conditions. The species legume have special prominence for that technique in function of the biomass production, being incorporate to the soil, promoting among other factors the enrichment of the soil in N favoring the development of other c enrichment of the soil in N favoring the development of other cultures. The gliricídia (Gliricidia sepium) is an arboreal legume of fast growth and deep fixation root with good tolerance to the drought. Studies with this species prove his/her potential for implementation in systems agosilvopastiris. However, and shortage of knowledge deepened on their nutritional demands can hinder the rational use of all his/her potential, because in general forest species present characteristics different from behavior as for the nutritional demands. The knowledge of the nutritional behavior to each species generates larger productivity, economy and smaller environmental impacts in the forest plantings. This study was divided in two chapters the first being a bibliographic review addressing the main causes of soil degradation and the basic principles for recovery of such areas et the secund chapter an experiment in conditions of house of vegetation (UAEF / CSTR / UFCG / Campus of Duck-PB) during a period of 120 aiming at to evaluate the behavior of gliricídia seedlings submitted to the application of N and P, in different levels (0, 50, 100, 150 and 200 mg dm-3 of N and 0, 25, 50, 75 and 100 mg dm-3 of P).