DRY MATTER DECOMPOSITION OF COVER CROPS IN A NO-TILLAGE COTTON SYSTEM

Authors

  • João Luís da Silva Filho Embrapa Algodão, Campina Grande, PB
  • Ana Luíza Dias Coelho Borin Embrapa Algodão, Campina Grande, PB
  • Alexandre Cunha de Barcellos Ferreira Embrapa Algodão Núcleo do Cerrado (Embrapa Arroz e Feijão) Rodovia GO-462, km 12 Zona Rural C.P. 179 75375-000 Santo Antônio de Goiás, GO

DOI:

https://doi.org/10.1590/1983-21252018v31n201rc

Keywords:

Exponential model. Michaelis-Menten. Gossypium hirsutum. No-tillage.

Abstract

No-tillage cotton systems require soil coverage with cover crop residue for a longer time due to the late cycle of cotton. However, decomposition rates may vary between cover crops, and the adjustment of models to describe it is critical to no-tillage cotton management. Two non-linear regression models, exponential (EM) and Michaelis-Menten (MM), were adjusted to dry matter decomposition of cover crops in a cotton no-tillage system, in Brazil. Three field trials were performed in 2012 for the cover crops Urochloa ruziziensis (brachiaria), Pennisetum glaucum (pearl millet), and Cajanus cajan (pigeon pea). Samples of cover crop were collected at 20, 50, 70, 110, 140, and 170 days after sowing upland cotton to measure dry matter decomposition. MM showed better adjustment than EM for all cover crops. The estimations of half-life parameters were different between the cover crops, suggesting that each cover crop has its own rate of decomposition. For pearl millet, brachiaria, and pigeon pea, the half-life estimation by exponential model was over the MM in 9, 12, and 12 days.

Author Biographies

  • João Luís da Silva Filho, Embrapa Algodão, Campina Grande, PB
    Engenheiro Agrônomo Doutor em Genética e Melhoramento de Plantas Melhoramento do Algodoeiro
  • Ana Luíza Dias Coelho Borin, Embrapa Algodão, Campina Grande, PB
    Engenheira Agrônoma Doutora em Ciência do Solo Pesquisadora em Fertilidade do Solo e Nutrição de Plantas
  • Alexandre Cunha de Barcellos Ferreira, Embrapa Algodão Núcleo do Cerrado (Embrapa Arroz e Feijão) Rodovia GO-462, km 12 Zona Rural C.P. 179 75375-000 Santo Antônio de Goiás, GO
    Engenheiro Agrônomo Doutor em Produção Vegetal Pesquisador em Fitotecnia e Sistemas de Produção

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Published

06-04-2018

Issue

Section

Agronomy