Nitrogen fertilization on palisadegrass: phytomass decomposition and nutrients release

• Autor(a) principal: Costa, Claudio Hideo Martins Da
• Data de Publicação: 2016
• Outros Autores: Crusciol, Carlos Alexandre Costa, Soratto, Rogério Peres, Ferrari Neto, Jayme, Moro, Edemar
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/1983-40632016v4639297; http://hdl.handle.net/11449/158215
• topic: Urochloa brizantha; cellulose; lignin; straw persistence; nutrients recycling; Urochloa brizantha; celulose; lignina; persistência de palhada; reciclagem de nutrientes

ABSTRACT Topdressing or pre-seeding nitrogen (N) application increases phytomass production, providing a higher nutrients accumulation and indirectly favoring the subsequent crop. However, N fertilization can alter the dry matter decomposition and nutrients release dynamics. This study aimed at evaluating the decomposition rate, cellulose, lignin and nutrients release speed from palisadegrass as a function of N fertilization. The experimental design was randomized blocks with four replications, in a factorial scheme constituted by two N fertilization levels and six sampling times after desiccation [0, 14, 34, 41, 51 and 68 days after management (DAM)]. The topdressing N fertilization on palisadegrass increases the dry matter production and N accumulation, but does not alter the decomposition and release speed. N fertilization reduces the C/N ratio, but it does not change the contents of cellulose and lignin and the decomposition and release of N, K, Ca, Mg, C and Si. The amounts of P and S accumulated in the plant and released into the soil increase with N fertilization. The maximum release rates occur within 0-14 DAM, being more intensive for P and S when N is applied. These results demonstrate the high potential of this species for crop-livestock integration systems, with some advantages that can be potentialized with higher N doses.