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

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 mod...

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Bibliographic Details
Authors: Silva Filho, João Luís da, Borin, Ana Luíza Dias Coelho, Ferreira, Alexandre Cunha de Barcellos
Format: article
Status:Published version
Publication Date:2018
Country:Brasil
Institution:Universidade Federal Rural do Semi-Árido (UFERSA)
Repository:Revista Caatinga
Language:English
OAI Identifier:oai:ojs.periodicos.ufersa.edu.br:article/6235
Online Access:https://periodicos.ufersa.edu.br/caatinga/article/view/6235
Access Level:Open access
Keyword:Exponential model. Michaelis-Menten. Gossypium hirsutum. No-tillage.
Modelo exponencial. Michaelis-Menten. Gossypium hirsutum. Plantio direto.
Description
Summary: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.