Comparação das comunidades de Sminthuroidea e Onychiuridae (Collembola) entre plantio direto em três níveis de fertilidade, plantio convencional e um ecossistema natural (campo nativo) em Ponta Grossa, Paraná, Brasil

Abstract

ABSTRACT. Comparison of lhe com m unities of Sminthuroidea and Onych iu r idac (Collembola) alllon g no-tillage in tllree leveIs of fcrt ility, conve ntional tillagc a nd a natura l ecosystem (native grassland) in Ponta Grossa, Paraná, Brazil. This work had as objective to compare the communities ofSminthuroidea and Onychiuridae (Collembola) among no-tillage in three fertility leveis, conventional tillage and a natural ecosystem (native grassland). ln the conventional tillage 3nd in the no-tillage in area of medium fertility, the community of Sminthuroidea had regular fluctuation along the period of the experiment, but with low densities. The no-tillage in area of high fertility presented a populational pick in the autumn; the no-tillage in area of low feI1ility , in the spring; and, the natural ecosystem, in the summer. As the final mean density ol"the population ofSminthuroidea, was observed that the no-tillage in area of low fertility went numerically superior to the others, proceeded by the natural ecosystem, no-tillage in area ofhigh fertility , conventional tillage, and, fina lly, no-tillage in area of medium fertility. Onychiuridae had three populational picks in the no-tillage in area oflow fel1ility: being a larger in the winter and other two, smaller in the summer and in the autumn. ln the no-tillage in area 01" medium fertility presented only a populational pick in the winte ... ln the other treatments there was not signiticantly populational picks. ln relation to the final mean density ofthe community ofOnychillridae, the no-tillage plantation in area of low fel1i li ty was superior, proceeded by the other treatments of no-tillage, and, in third plan, the natural ecosystem and the conventional tillage. KEY WORDS. Collembola, Onychillridac, Sminthllroidea, no-tilIage, conventional tilIage Atualmente a agricu ltura tem assumido, de forma crescente, caráter complexo e intensivo, caracterizado por uma exploração do solo que não respeita sua capacidade de uso (FANCELLI & FAVAR1N 1989). Esta prática trouxe sérios prejuízos ao meio ambiente e para o próprio homem . Visando minimizar estes danos, o homem está a procura de um modo de cultivar o solo, que lhe deixe o mais próximo das condições naturais.