ORGANIC RESIDUE AND PHOSPHORUS AS CONDITIONERS OF DEGRADED SOIL AND EFFECTS ON THE INITIAL GROWTH OF Dipteryx alata Vog.

Na regi\ue3o Noroeste do Estado de S\ue3o Paulo, foi estabelecida, em 1965, a Usina Hidrel\ue9trica de Ilha Solteira (CESP), que produziu extensas \ue1reas degradadas, de onde foram retiradas as camadas superficiais do solo. Para o restabelecimento da vegeta\ue7\ue3o, em \ue1reas como estas, \ue9 necess\ue1ria a adi\ue7\ue3o de insumos qu\uedmicos e mat\ue9ria org\ue2nica. Associando-se a presen\ue7a na regi\ue3o de macr\uf3fitas \ue0 necessidade de recupera\ue7\ue3o de \ue1reas degradadas e a disponibilidade de sementes de esp\ue9cies nativas de cerrado, prop\uf4s-se o desenvolvimento deste trabalho, com o objetivo de avaliar os efeitos da adi\ue7\ue3o de res\uedduo org\ue2nico e f\uf3sforo sobre material de solo degradado e sobre o crescimento inicial de Dipteryx alata , esp\ue9cie arb\uf3rea de cerrado. O material de solo foi coletado em \ue1rea degradada pela constru\ue7\ue3o da Usina Hidrel\ue9trica de Ilha Solteira (SP). O experimento foi conduzido em dois ambientes, casa de vegeta\ue7\ue3o e a pleno sol. Os tratamentos consistiram de quatro doses de f\uf3sforo (0, 100, 200 e 300 mg dm-3 de P2O5), com ou sem adi\ue7\ue3o de macr\uf3fitas, produzindo 16 tratamentos com 10 repeti\ue7\uf5es cada um. As macr\uf3fitas utilizadas, coletadas na Usina Hidrel\ue9trica de Jupi\ue1 (MS), foram secas e passadas em picadeira, incorporadas ao material de solo e incubadas por 60 dias. As sementes de Dipteryx alata, coletadas nas proximidades da \ue1rea, foram semeadas em areia lavada e ap\uf3s 60 dias introduzidas nos tratamentos. As plantas foram avaliadas mensalmente quanto \ue0 altura, ao di\ue2metro do caule e \ue0 clorofila foliar. Ap\uf3s 210 dias, as plantas foram coletadas e avaliadas para peso fresco e seco da parte \ue1rea e do sistema radicular e o material de solo foi avaliado quanto \ue0 fertilidade e atividade microbiana pelo carbono do CO2 liberado. A incorpora\ue7\ue3o de res\uedduo org\ue2nico ao material de solo degradado afetou positivamente a fertilidade deste e a atividade microbiana. As doses de f\uf3sforo aplicadas influenciaram o comportamento de Ca, SB, H+Al e CTC e, quando aplicadas na aus\ueancia de res\uedduo org\ue2nico, promoveu incrementos significativos e lineares nos valores da acidez potencial, mostrando a import\ue2ncia da presen\ue7a do res\uedduo org\ue2nico. O crescimento inicial do Dipteryx alata foi favorecido pelo cultivo protegido, pela incorpora\ue7\ue3o de res\uedduo org\ue2nico e pela adi\ue7\ue3o de f\uf3sforo ao solo. Pode-se concluir ainda que h\ue1 boa perspectiva para deposi\ue7\ue3o deste res\uedduo sobre o material de solo degradado, embora estudos em condi\ue7\uf5es de campo sejam necess\ue1rios.In northwestern S\ue3o Paulo State, it was established, in 1965, the hydroelectric station of Ilha Solteira(CESP) that produced extensive degraded areas, from where it was removed the soil superficial layers. For the re-establishment of the vegetation, in areas like these, it is necessary the addition of chemical inputs and organic material. Associating the presence in the area of macrophytes, to the need of recovery of degraded areas and the availability of seeds from native species of Cerrado, it was intended the development of this work, with the objective of evaluating the addition effects of organic residue and phosphorus on the material of degraded soil and on the initial growth of Dipteryx alata , arboreal species of \u2018cerrado\u2019. The soil material was collected in area of degraded soil by the construction of Ilha Solteira hydroelectric station. The experiment was conducted in two environmental conditions, greenhouse and plenty of sun. The treatments consisted of four phosphorus doses (0, 100, 200 and 300 mg dm-3 of P2O5), with or without macrophytes addition, with 16 treatments and 10 repetitions each one. The used macrophytes, collected at Jupi\ue1 hydroelectric station, in Mato Grosso do Sul state, were dried, sliced, incorporated to the soil material and incubated during 60 days. The seeds of Dipteryx alata, collected around of the area, were sowed in washed sand and after 60 days introduced in the treatments. The plants were appraised monthly for height, stem diameter and leaves chlorophyll. After 210 days, the plants were collected and evaluated for fresh and dry weight of aerial part and radicular system and the soil material was evaluated for fertility and microbial activity by the carbon of liberated CO2. The organic residue, incorporated to the material of soil degraded, positively affects the soil fertility and the soil microbial activity. The applied phosphorus doses influenced the behavior of Ca, SB, H+Al and CTC, when applied in the absence of organic residue, it promoted significant and linear increments for values of potential acidity, and indicated the organic residue importance. The initial growth of the Dipteryx alata was favored by the protected cultivation, for the incorporation of organic residue and for the phosphorus addition to the soil. At the end although the material of degraded soil comes as good perspective for disposal of this residue, studies about the field conditions are necessary