Volume 153, November 2015, Pages 169–174
- a Agronomic Institute of Parana (IAPAR), Rodovia Celso Garcia Cid, km 375, 86047-902 Londrina, PR, Brazil
- b Post-Doctoral National Program—PNPD/Brazilian Agency of Coordination for the Improvement of Higher Education Personnel—CAPES, Post Graduate Program in Conservation Agriculture at IAPAR, Brazil
- c Under Graduated Student from North State University of Paraná (UNOPAR)/Paraná State Internship Central Grant at IAPAR, Brazil
- d Brazilian Corporation of Agricultural Research (EMBRAPA), Rua XV de Novembro, 1452, 3560-970 São Carlos, SP, Brazil
- Received 19 November 2014, Revised 8 May 2015, Accepted 5 June 2015, Available online 25 June 2015
Highlights
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- SOM quality was assessed on different cover crop/weed control methods.
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- Humification degree was assessed by Laser Induced Fluorescence Spectroscopy (LIFS).
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- Lower weed incidence was found at dwarf mucuna cover crop areas.
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- Higher C content was observed at superficial layers on cultural weed control area.
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- Higher humification degree at depth for all cover crops and weed control methods.
Abstract
Soil
organic matter (SOM) plays an important role for soil quality and
productivity maintenance, acting as energy source, promoting biological
diversity, enhancing terrestrial ecosystems composition. This study
assessed the effects of long-term weed control and cover crops between
coffee rows on SOM quality in a very clayey (80 dag kg−1 of
clay) Typic Haplorthox (Dystroferric Red Latosol) from State of Paraná,
Southern Brazil. Seven weed control and cover crops were assessed
between coffee rows: (i) hand weeding—HAWE; (ii) portable mechanical
mower—PMOW; (iii) pré + post-emergence herbicides—HERB; (iv) peanut
horse (Arachis hypogeae) cover crop—GMAY; (v) dwarf mucuna (Mucuna deeringiana)
cover crop—GMMA; (vi) no-weed control between coffee row—SCAP; (vii)
weed check—CONT. Soil samples were collected in the center of the
inter-rows between coffee trees at four depths: 0–10 cm, 10–20 cm,
20–30 cm, and 30–40 cm. SOM quality assessment included total soil
organic carbon (SOC) content and organic matter humification degree (HFIL)
by laser-induced fluorescence spectroscopy (LIFS). C content was up to
26% higher for SCAP and CONT samples, compared to the other field
conditions, denoting influence of plant material accumulation at top
soil (0–10 cm). Higher HFIL results (up to 47%) were observed
at deeper layers, inferring incidence of less humified/labile
structures at top soil, and condensed/recalcitrant character for organic
matter at depth, regardless of cover crops and weed control method
considered. In terms of weed density it was observed a higher negative
impact on weed growth in areas under GMMA cover crop (decrease of 90.8%
in weed density). The behavior may be attributed to the chemical
composition of the species, ultimately leading to possible occurrence of
allelopathic phenomenon.
Keywords
- Weed density;
- Total organic carbon;
- Humification degree;
- Cover crops;
- Weed control methods
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