Data/hora: 29/06/2024 09:25:58

Biblioteca(s): 	Epagri-Sede.	
Tipo da produção científica: 	Artigo em Anais de Congresso / Nota Técnica	
Data corrente: 	08/07/2018	
Data da última atualização: 	08/07/2018	
Autoria: 	SANTOS, L. H.; LOSS, A.; CANTON, L.; SANTOS JÚNIOR, E.; KURTZ, C.; BRUNETTO, G.; COMIN, J. J.	
Título: 	Carbon of humic substances in soil aggregates cultivated with onion under no-till and conventional tillage systems.	
Ano de publicação: 	2018	
Fonte/Imprenta: 	IDESIA, Arica, Chile, v. 36, n. 1, p. 15-25, 2018.	
Idioma: 	Inglês	
Conteúdo: 	Carbon (C) contents of humic substances (HS) in soil aggregates are a sensitive indicator of changes in the edaphic quality caused
by soil management systems and/or cover plant species. The aim of this study was to assess total contents of C and HS of organic
matter in soil aggregates cultivated with onion under a no-till vegetable production system (NTVS) and conventional tillage (CT)
compared to a secondary forest area. Treatments consisted of single and mixed cover crops and onion under NTVS: spontaneous
vegetation, 100% black oat; 100% rye; 100% oilseed radish; consortium of oilseed radish (14%) + rye (86%); consortium of oilseed
radish (14%) + black oat (86%). An area cultivated with onion under CT (± 37 years) and a forest area (secondary forest; ± 30
years) were also evaluated. Five years after implementation of NTVS, undisturbed soil specimens were collected from the 0.0-0.05,
0.05-0.10 and 0.10-0.20 m layers and aggregates were obtained (8.00 mm > Ø &#8805; 2.0 mm). In these aggregates, total organic carbon
(TOC) and C of HS were determined, subdividided into a fulvic acid fraction (C-FAF), humic acid fraction (C-HAF) and humin
(C-HUM). With the C values of the HS the following ratios were calculated: C-HAF/C-FAF and (C-HAF+C-FAF)/C-HUM. The
highest content of TOC, C-FAF, C-HAF and C-HUM were found in the forest. In NTVS, the contents of TOC (at the 0.0-0.05 m
depth) and C-HUM (0.0-0.05 and 0.05-0.10 m) were higher than those found under CT. The highest C-FAF contents were found
under CT. NTVS compared to CT favors the humification process (higher C-HUM content and lower ratios of C-HAF+C-FAF/CHUM (at the 0.0-0.05 and 0.05-0.10 m depths) and the protection of organic matter (higher TOC contents at the 0.0-0.05 m depth)).
A linear relationship was observed between C-HUM and N of HS. Among the cover plant species, rye alone and rye combined
with oilseed radish had the best results regarding humification of organic matter with predominance of C-HUM and C-HAF. This
pattern was also observed in the control for C-HUM, due to the abundance of plant families and species, indicating that plant
biodiversification is an effective way to improve the quality of soil.	
Palavras-Chave: 	Alliun cepa L; consortium of cover crops; fulvic acids; humic acids; humin; macro-aggregates.	
Categoria do assunto: 	F Plantas e Produtos de Origem Vegetal	
URL: 	http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_40949.pdf	
Registro original: 	Epagri-Sede (Epagri-Sede)	
Exemplares: 	Epagri-Sede - (102477-1) - UPC - AP - DD -  -  -  - DIS