Avaliação da fertilidade do solo e do estado nutricional dos pomares cítricos nos municípios de Muritiba e Governador Mangabeira – Bahia

Abstract

The research had the objective of evaluating the soil fertiility and nutritional state of orchards with "Pera" orange trees grown in distrophic yellow latosol, in Muritiba and Governador Mangabeira municipality, localized in Reconcavo Sul Baiano. The physical contitions of the soil were evaluated through particle size analysis and the chemical characteristics by the determination of organic matter, P, K, S, Ca, Mg, H + Al, Cu, Fe, Mn and Zn contents and pH, calculating the sum of bases, CEC, and base saturation. The N, P, K, Ca, Mg, S, Cu, Fe, Mn and Zn contents were also determined in leaf samples. For the soil and leaf sampling 34 orchards of "Pera" cultivar grafted on "Cravo" lemmon plants were selected and in each orchard 25 plants from each quadrant were defined for leaf samplings. The soil samples for chemical analysis were collected at the projection of shoot canopy, from the four quadrants of each plant, at 0 to 20 and 20 to 40 cm depth. The orchards were geo-referenced for the elaboration of soil fertility and nutritional state map. The results of soil and plant samples chemical analysis were submitted to descriptive statistical methods and Pearson correlation, and lime and macro and micronutrient ferilizers requirement for each municipality were calculated. The results indicated that: The soil organic matter, S, P, K, Ca, and Mg contents were classified as bellow the adequate level; Cu, Mn, and Zn as medium to low and low for Fe. In the leaf diagnosis, the N, S and K were classified as adequate to high, Mg as high to excessive, P and Cu as adequate, Ca and Fe low and Mn and Zn as deficients. The recommendation for soil acidity and fertility amendment indicate the needs of liming, NPK fertilization in lower dosis for Muritiba and foliar Mn and Zn application and a local experiments to define the calibration curve of soil analysis for acidity and fertilizer (macro and micro) amendment in citrus.