Vanderlise Giongo

Composto orgânico em mangueiras (Mangifera indica L.) cultivadas no semiárido do nordeste brasileiro

The objective of this study was to evaluate the soil chemical characteristics, the nutrient contents in leaves and the production of mango crops grown in the organic system. An experiment was carried out with three composts named A, B and C, using three levels (0, 5 and 10 t ha-1) of each compost in a commercial production of mango on organic cultivation. The experiment was carried out in a randomized block design, 3 x 3 factorial (3 composts x 3 levels) and three replications. The organic composts were prepared with animal and vegetable waste, enriched with castor bean, MB4® and thermo phosphate. The enrichment was efficient in increasing the content of nutrients in composts. The organic composts increased the levels of soil organic matter (SOM), especially in the compost C, whose soil analysis showed higher levels of total P, K, Ca, Mg, B, Cu, Mn and Zn. The SOM increased linearly with the enhancement of the compost levels. Production and fruit number per plant were higher with the use of the B and C composts, which showed higher contents of total nutrients. The compost levels provided a linear increase in N leaf content. The production of fruit (kg ha-1) and fruit number per plant showed quadratic increase with the compost concentrations, without presenting a maximum point.

Decomposição e liberação de nutrientes de coquetéis vegetais para utilização no Semiárido brasileiro

The decomposition and release of nutrients from plant residues can play an important role in the maintenance of soil fertility in semi-arid regions. Thus this study aimed to evaluate the rate of decomposition of dry matter (DM) and the release of carbon (C) and nutrients from plant mixtures used as green manure in the Brazilian Semi-arid regions. The experiment was carried out in a greenhouse, from November 2007 to July 2008, using plant mixtures made up of leguminous species (L) (calopo, Crotalaria juncea, Crotalaria spectabilis, jackbean, pigeon pea, lab-lab) and non-leguminous species (NL) (sesame, sunflower, castor, millet and sorghum) combined to give the following treatments: T1 - 100% NL, T2 - 100% L, T3 - 75% L and 25% NL, T4 - 50% L and 50% NL, T5 - 25% L and 75% NL. The rates of decomposition and the release of nutrients were monitored through collection of the residue at 8; 15; 30; 60; 90; 120; 150; 180 and 210 days after the beginning of the experiment. A randomized-block design was used, with three replications. The mixtures showed similar decomposition rates of DM and nutrient release, except for Ca, Cu and Mn, where the mixtures composed predominantly of NL species showed a higher release rate./ From the average values of k for all of the mixtures, it was possible to establish the following order of release of macronutrients: K> N> Ca> Mg> P and micronutrients: Fe> Mn> Cu> Zn> B.

Physical attributes of ultisol of Brazil’s northeastern semiarid under organic farming of wine grapes

The purpose of this study was to evaluate the effects of organic farming of wine grapes under physical and chemical characteristics of Ultisol Brazils northeastern semiarid region. The samples of soil were collected from the row and interrow of the farming and from the fallow area, at the depths of 0.0-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.60 m. The samples were collected at six and twelve months after the culture implementation to evaluate the state of aggregation, bulk density and total soil porosity, flocculation index and organic matter contents, calcium, magnesium, and sodium. The results were submitted to statistical analysis. The adoption of organic farming contributed to the soil aggregation process. The bulk density and total soil porosity did not differ significantly between the evaluations, but were within the critical limits for sandy soils. The index flocculation did not have a great influence on the aggregates formation, being this process influenced by organic matter. The period of one year was considered short to obtain conclusive results in improving the soil quality by organic farming, since there are difficulties in tropical soils in promoting significant increases in organic matter content in short time.

FRAÇÕES HUMIFICADAS DA MATÉRIA ORGÂNICA EM FUNÇÃO DO CULTIVO DE COQUETÉIS VEGETAIS

The aim of this study was to assess the organic matter changes in quantity and quality, particularly of the humic fraction in the surface layer (0–20 cm), of a Typic Plinthustalf soil under different management of plant mixtures used as green manure for mango (Mangifera indica L.) crops. The plant mixtures, which were seeded between rows of mango trees, were formed by two groups of leguminous and non -leguminous plants. Prior to sowing, seeds were combined in different proportions and compositions constituting the following treatments: 100% non-leguminous species (NL); 100% leguminous species (L); 75% L and 25% NL; 50% L and 50% NL; 25% L and 75% NL; and 100% spontaneous vegetation, considered a control. The plant mixtures that grew between rows of mango trees caused changes in the chemical composition of the soil organic matter, especially for the treatments 50% L and 50% NL and 25% L and 75% NL, which increased the content of humic substances in the soil organic matter. However, the treatment 25% L and 75% NL was best at minimising loss of total organic carbon from the soil. The humic acids studied have mostly aliphatic characteristics, showing large amounts of carboxylic and nitrogen groups and indicating that most of the organic carbon was formed by humic substances, with fulvic acid dominating among the alkali soluble fractions.

Uso Atual e Quantificação de Áreas Degradadas na Margem Direita do Rio São Francisco no Município de Curaçá-BA (Current Use and Quantification of Degraded Areas at the Right Riverside of São Francisco River at Curaçá Municipality (Bahia, Brazil))

A paisagem do Submedio do Vale do Sao Francisco tem, ao longo dos anos, passado por constantes alteracoes devido as atividades antropicas, onde a vegetacao original da Caatinga hiperxerofila foi gradativamente sendo eliminada pelo processo extrativista e parte cedendo espaco ao processo de uso agricola. Dessa maneira, muitas areas sem aptidao ou de aptidao restrita para o uso agricola sao cultivadas, aumentando o risco de degradacao pelo efeito da erosao que atinge, inclusive, a vegetacao ciliar. A recuperacao desta vegetacao e um grande desafio, haja vista as dificuldades de conciliar a garantia do sustento das familias ribeirinhas e de torna-las parte integrante deste processo de reconstituicarrro da mata ciliar. O objetivo geral deste estudo foi avaliar o uso e ocupacao dos solos e integrar e fortalecer estudos ambientais para a preservacao da vegetacao ciliar. Tambem visou contribuir com a recuperacao de areas degradadas, florestamento, reflorestamento e ecossistemas agrossilviculturais, encaminhados ao Programa de Revitalizacao da Bacia do Rio Sao Francisco, para os municipios de Curaca no Estado da Bahia. Inicialmente foram realizados estudos basicos que indicaram o municipio de Curaca apresentou a maior percentagem de areas degradadas (13,21%). As areas com vegetacao de Caatinga arbustiva se destacam na maior parte do municipio estudado. De um modo geral, pode-se dizer que no municipio, praticamente toda a vegetacao ciliar foi retirada e que a grande maioria dos solos relacionados aos sedimentos fluviais encontra-se em via ou com elevado grau de salinizacao e degradacao.