395-6 Mulch Addition Increase Growth, Yield and Soil C and N in a Managed Full-Sun Coffee System in Hawaii.

Poster Number 1832

See more from this Division: SSSA Division: Soil Biology & Biochemistry
See more from this Session: General Soil Biology & Biochemistry: II

Wednesday, November 6, 2013
Tampa Convention Center, East Exhibit Hall

Adel Youkhana, University of Hawaii at Manoa, Honolulu, HI and Travis w. Idol, Natural Resources and Environmental Management, University of Hawaii at Manoa, Honolulu, HI
Poster Presentation
  • Youkhana & Idol poster for ASA,CSA,SSA 2013-Florida_Tampa meetings.pdf (1.5 MB)
  • Abstract:
    The objectives of this study were to evaluate the potential of a cut-and-carry system of mulch additions for open-grown coffee in Hawaii, utilizing the multipurpose nitrogen-fixing tree Leucaena variety KX2. A stand of Leucaena-KX2 trees were pollarded every 6 months, and the pollarded material was chipped and added to open-grown coffee plots on an equal-area basis. Approximately 65 Mg ha‑1 of mulch dry matter was added over a 3-year period, including ~27.5 Mg ha‑1 of C and ~530 kg ha‑1 of nitrogen (N). Plots without mulch addition were fertilized with equivalent amounts of inorganic N for comparison. Mulch decomposition averaged 64% over the first year and followed first-order decay dynamics. Net N mineralization was positive by 3 months after addition. There was significant loss of all major biochemical components during the decomposition process. Mulching increased soil carbon dioxide (CO2) efflux by 0.75 (µmol m-2 sec-1). Total soil C and N increased by 2.90 and 1.42 Mg ha-1, respectively. Mulch addition significantly increased all measures of coffee growth and yield over two years, except for average bean weight. Where space is available or shade is undesirable, a cut-and-carry mulching system using Leucaena-KX2 can increase soil C and N and coffee growth and yield.

    See more from this Division: SSSA Division: Soil Biology & Biochemistry
    See more from this Session: General Soil Biology & Biochemistry: II