CRESCIMENTO E COMPOSIÇÃO QUÍMICA DE ERVA-MATE (Ilex paraguariensis ST. HIL.), TRANSCORRIDOS OITO ANOS DE CALAGEM

O estudo com a erva-mate (Ilex paraguariensis St. Hil.) foi desenvolvido com o intuito de avaliar o efeito residual da calagem no crescimento e na composicao quimica foliar, transcorridos oito anos da aplicacao. O delineamento estatistico utilizado foi de blocos ao acaso com 5 tratamentos, 6 repeticoes e 16 plantas uteis por parcela. Os tratamentos visaram atingir as seguintes saturacoes por bases na implantacao: T1=11,6% (testemunha); T2=25%; T3=50%; T4=75% e T5=100% em um Cambissolo Alico. Concomitantemente com o plantio foi realizada uma adubacao basica com ureia, cloreto de potassio e superfosfato simples. Foram avaliados o diâmetro, a altura da copa, o peso da massa verde, o peso da massa seca e os teores foliares de K, Ca, Mg, Mn, Fe, Cu e Zn, atraves de digestao sulfurica. Nao foram observadas diferencas significativas para as variaveis de biomassa analisadas. Nao se constatou efeito significativo da calagem na composicao quimica foliar, transcorrido um periodo de 8 anos. Conclui-se que o efeito da calagem cessou de influenciar as plantas apos este periodo, considerando-se os elementos investigados e o processo analitico. GROWTH AND CHEMICAL COMPOSITION OF ERVA-MATE (Ilex paraguariensis ST. HIL.), AFTER EIGHT YEARS FROM LIMING Abstract The study was developed with the purpose to detect a residual effect of a liming treatment after 8 years from application on the development and leaf composition of erva mate (Ilex paraguariensis St. Hil). The treatments were arranged in a complete block design. Five levels of base saturation were established: T1=11,6% (control); T2=25%; T3=50%; T4=75% e T5=100%. The soil is a typical "Cambissolo Alico" (Inceptisol). Each experimental unit was represented by 16 plants with 6 repetitions. A basic fertilization with urea, simple superphosphate and potassium cloride was also applied. The plants were measured for height growth and crown diameter. Leaf samples were collected from the middle of the crown and analysed for K, Ca, Mg, Fe, Mn, Cu and Zn by the sulfuric acid method. In this sense, no significant effect of the liming treatment was observed after a period of eight years. The contrary was observed at eight month of age, where significant differences in the leaves were observed for K, Ca, Mg, Mn and Cu according to the liming treatments. Based on the first evaluation at eight months, the results lead to the conclusion that there is no residual effect of liming after that period of time concerning development and leaf composition for the studied elements.