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Comparison of three systems of decomposition of agricultural residues for the production of organic fertilizers
Sánchez-Rosales, Rocío; Hernández-Rodríguez, Adriana; Ojeda-Barrios, Dámaris; Robles-Hernández, Loreto; González-Franco, Ana Cecilia & Parra-Quezada, Rafael
Abstract
Organic wastes (OW) of diverse nature must be subjected
to controlled decomposition processes to avoid risks of
contamination and obtain products useful for agriculture.
The objective of the present study was to compare over
time physical, chemical and enzymatic parameters of OW
transformed as vermicomposting (VC), semicomposting
(SC) and composting (CP) for elaboration of organic
fertilizers. A mixture of bovine manure and sawdust was
subjected to each of three systems for 183 d. Temperature,
total N (Nt), organic C (OC), C/N ratio, pH, enzymatic
urease activity (EUA), germination index (GI) and
electrical conductivity (EC) were measured throughout the
time of study. The variables evaluated showed significant
differences between time and treatment. The temperature
ranged between 20 and 34 °C in VC and SC, while in CP
between 20 and 61 °C. All three systems reduced the C/N
ratio to less than 15/1. The CP product had higher pH, EC,
and EUA values than both VC and SC. The VC product
had the highest GI values. All the products obtained at 183
d were within the parameters to be considered as organic
fertilizers, but the SC product transformed into an organic
fertilizer fastest and had least water usage.
Keywords
Compost; semicomposting; vermicomposting.
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