Contribuição da adubação orgânica na absorção de nutrientes e na produtividade de milho no semiárido paraibano

Abstract

The aim of this study was to evaluate the contribution of the form and timing of application of organic fertilizers of different grades for nutrients uptake and its relation to the productivity of corn grown in Fluvic Entisol in the semiarid region of the Paraiba State, Brazil. The experiment was conducted at Vila Maria Rita Agroecological Station, in the Cariri region of the state, in a randomized complete block design with four replications. The treatments were: T1 -built-in application of 20 Mg ha-1 of soil gliricidia (GI); T2 -sidedress application of 20 Mg ha-1 of gliricidia (GC); T3 -built-in application of 10 Mg ha-1 manure and 10 Mg ha-1 biomass gliricidia (EI+ GI); T4 -application of 10 Mg ha-1 incorporated manure and 10 Mg ha-1 in sidedress, 45 days after sowing (EI + GC); T5 -built-in application of 10 Mg ha-1 manure (EI); T6 - control without application of organic manure (C). The application of gliricidia in cover (GC) in the soil led to the greatest accumulation of nutrients in corn biomass. The presence of gliricidia alone or in combination with manure favored for a greater synchronization between the soil nutrients availability and the corn demand for nutrients. The application of gliricidia alone and in combination with manure favored the increase in the nutrients export through the straw and corn grain. The use of built-in gliricidia biomass alone and in combination with manure in the Fulvic Entissol is recommended to increase corn productivity.