Abstract

SALUME, Jamilli et al. Decomposition and nutrient release from cover crop residues under a pear orchard. Rev. de Ciências Agrárias [online]. 2020, vol.43, n.1, pp.159-174.  Epub Jan 24, 2020. ISSN 0871-018X.  https://doi.org/10.19084/rca.18391.

Our objective was to evaluate the dynamics of decomposition of crop residues in a pear orchard in Brazil. Residues of oat, oilseed radish, ryegrass and spontaneous vegetation were placed in litter bags and deposited at surface soil in the inter-row spacing of pear trees. After 0, 21, 36, 56 and 136 days, the dry matter, carbon, lignin, cellulose, non-structural components, and nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations were determined. Spontaneous vegetation residues had the longest half residence time compared to the introduced cover crops, while oat residues presented faster dry matter decomposition rates (2-3 fold higher). Oilseed radish and ryegrass showed the highest final remaining dry matter (26-36%), and the largest nutrients release. Oilseed radish and ryegrass residues released 85 kg N ha-1, 67 kg P ha-1, 48 kg K ha-1, 16 kg Ca ha-1, and 9 kg Mg ha-1. Oilseed radish can potentially benefit mineral nutrition of fruit trees, whereas the spontaneous vegetation is recommended to protect the soil agains the erosion and to contribute to the soil organic carbon stock in the long term.

Keywords : decomposition rate; litter bags; nutrient release; Pyrus communis L.cv. Rocha..

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