Desempenho da cultura da batata-doce sob manejo com cobertura morta vegetal e adubação orgânica no semiárido

Abstract

In order to guarantee fertile and sustainable production systems in the long term, in the face of edaphoclimatic changes and the intensive use of natural resources, the use of ecologically- based technologies has been sought, capable of mitigating pressures on production systems and providing better performance of agricultural crops. The objective was to evaluate the performance of the sweet potato crop under management with mulch and organic fertilization in the semi-arid region of Paraíba. The research was carried out at Fazenda Riachão, municipality of Aparecida, Paraíba, Brazil. The experiment was carried out in a randomized block design, based on the Composite Central de Box matrix, using five values of bovine manure (EB) doses (0.0; 8.72; 30; 51.28 and 60 t ha1) and mulch (CM) (0.0; 287.73; 989.50; 1691.27 and 1979.0 g m2), and two additional ones (I- control; II- fertilization with NPK 40-70- 90 kg ha1). Gas exchanges were evaluated; chlorophyll a fluorescence; leaf indices of chlorophyll; number of leaves, length and diameter of the main stem; leaf area; green and dry mass of the aerial part; foliar contents of nitrogen, phosphorus and potassium; total number of roots plant1; length and diameter of roots; commercial production, commercial and total productivity; average mass of roots; soluble solids, starch, protein and crude energy; pH; and levels of P, K, Fe and Mg in roots. The activity of chlorophyll contents and the efficiency of potassium and soluble solids are increased by fertilization with EB and use of CM. The dose between 30 and 60 t ha1 of EB associated with CM between 1179.0 and 1979.0 g m-2 stimulates greater diameter and length of the stem, greater production and commercial productivity of roots and establishes greater accumulation of green phytomass of the aerial part and leaf nitrogen. The CM over application between 1235.5 and 1979.0 g m2 promotes greater leaf area, greater accumulation of aerial part dry matter, greater root diameter and amount of iron and starch contents; The associated application of EB and CM, for sweet potato, is more efficient than mineral fertilization with NPK.