Comparison of 15N isotope methods to determine the recovery efficiency of nitrogen from green manure

Authors

  • Ednaldo da Silva Araújo Embrapa Agrobiologia, BR-465, Km 7, Ecologia, Caixa Postal 74505, CEP 23891-000 Seropédica, RJ, Brazil.
  • Bárbara Fernanda da Silva Universidade Federal Rural do Rio de Janeiro, BR-465, Km 7, CEP 23897-000 Seropédica, RJ, Brazil.
  • Emerson Dalla Chieza Universidade Federal do Maranhão, Avenida João Alberto, s/no, Bambu, Campus III, CEP 657418-000 Bacabal, MA, Brazil.
  • Segundo Urquiaga Embrapa Agrobiologia, BR-465, Km 7, Ecologia, Caixa Postal 74505, CEP 23891-000 Seropédica, RJ, Brazil.
  • José Guilherme Marinho Guerra Embrapa Agrobiologia, BR-465, Km 7, Ecologia, Caixa Postal 74505, CEP 23891-000 Seropédica, RJ, Brazil.
  • Janaína Ribeiro Costa Embrapa Agrobiologia, BR-465, Km 7, Ecologia, Caixa Postal 74505, CEP 23891-000 Seropédica, RJ, Brazil.
  • Jose Antonio Azevedo Espíndola Embrapa Agrobiologia, BR-465, Km 7, Ecologia, Caixa Postal 74505, CEP 23891-000 Seropédica, RJ, Brazil.

DOI:

https://doi.org/10.1590/S1678-3921.pab2019.v54.26599

Keywords:

Zea mays, biological nitrogen fixation, legume

Abstract

The objective of this work was to compare three methods of 15N isotope application to the soil in order to determine the recovery efficiency of nitrogen derived from green manure by corn (Zea mays). The used experimental design was a randomized complete block with six replicates. The treatments consisted of three 15N isotope methods: indirect method I, isotope dilution with 15N-labelled synthetic fertilizer applied through a small hole next to each corn plant; indirect method II, isotope dilution with 15N-labelled synthetic fertilizer spread in the furrow next to the corn planting row; and direct method, application of a legume straw as green manure, treated with 2.23% excess 15N. The green manure used was jack bean (Canavalia ensiformis). Applying synthetic 15N to the soil (indirect methods I and II) did not interfere in the estimation of the recovery efficiency of N derived from green manure. The recovery efficiency of N from green manure was 17% for the indirect methods, overestimated when compared with that of 7% for the direct method. The direct method is the most adequate to determine the recovery efficiency of N from green manure.

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Published

2019-10-14

How to Cite

Araújo, E. da S., Silva, B. F. da, Chieza, E. D., Urquiaga, S., Guerra, J. G. M., Costa, J. R., & Espíndola, J. A. A. (2019). Comparison of 15N isotope methods to determine the recovery efficiency of nitrogen from green manure. Pesquisa Agropecuaria Brasileira, 54(X), e00721. https://doi.org/10.1590/S1678-3921.pab2019.v54.26599

Issue

V.54, Jan./Dec., 2019 :Continuos publication

Section

QUANTITATIVE METHODS