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Manager Climate Corps
Pacific Islands Climate Adaptation Science Center

Can albizia mulch be used on agricultural land to replace fertilizer, improve agroecosystem functioning, and provide climate change mitigation and resilience?

Albizia being mulched by chipper
A chipper mulches invasive albizia to be utilized as an alternative to industrial fertilizers. Photo Credit: Joanna Norton, UH Hilo

6-min Summary Film (July 2019)

Project's Final Report (May 2019)

Project Summary: The challenges of food production, invasive species control, and climate change are intersecting, as they all stem from our ongoing use of land and energy on a global scale. In East Hawai‘i, two problems involving these issues are reflective of global trends. First, an expansion of agriculture is needed here, yet upland agricultural tracts are typically troubled by inherent low fertility, physically degraded, and depleted of soil carbon from tillage. They can require fertilizer inputs that are environmentally costly. Second, the invasive, nitrogen-fixing tree Falcataria moluccana (albizia) is dominating landscapes and altering ecosystems with rapidcycling carbon and nitrogen inputs. These two problems are predicted to intensify with climate change, as growing conditions in each region shift and higher temperatures and carbon dioxide levels favor fast-growing, N-fixing species. Yet each of these problems could hold a remedy for the other, using practices described in the new field of climate-smart agriculture (CSA). Hawai‘i Island presents a unique opportunity to test whether or not accumulated nutrients from F. moluccana growth can be used as a compost that can benefit agricultural systems lacking in fertility, due to the intensity and grave consequences of the F. moluccana invasion, as well as the underutilization of agricultural land and lack of food self-sufficiency in Hawai‘i. The Big Island Invasive Species Committee (BIISC) has deemed F. moluccana one of the worst invasive species on this island, and while they have made great strides controlling the tree near power lines and human habitation, there is a gap in knowledge about how the biomass from this tree can be utilized. This study examined whether compost from F. moluccana can replace chemical fertilizer and store carbon in agricultural lands in East Hawai‘i. This research was designed and completed with the partnership of invasive species managers and farmers to maximize the usefulness of the research to the local community.

Primary Contact and Masters Graduate Student

Faculty Advisor

  • Rebecca Ostertag , Associate Professor of Biology, University of Hawaiʻi at Hilo

Committee Members

  • Bruce Mathews , Professor of Soil Science, University of Hawaiʻi at Hilo
  • Flint Hughes, Ecosystem Ecologist, Institute of Pacific Islands Forestry, US Forest Service

Partner

  • Springer Kaye, Big Island Invasive Species Committee

Project Start Date: August 2016
Project Completion Date: May 2019


farmers planting cassava
MCC Graduate Student Joanna Norton and Oʻahu Farmers planting cassava in a field prepared with wood mulch compost. Photo Credit: Joanna Norton, UH Hilo

Project Information

Final Report (May 2019)

Progress Report (November 2017)

2-Page Project Overview

6-min Summary Film


Project in the News

UH Hilo Stories article


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Partner Agencies

UH Manoa

University of Guam

Department of the Interior

USGS

Pacific Islands Climate Adaptation Science Center

Contact MCC Staff

  • Sharon Ziegler-Chong: University Consortium Lead
  • Phone: (808) 933-0759
  • Email: ziegler@hawaii.edu

The MCC partners with the Tropical Conservation Biology and Environmental Science Graduate Program at UH Hilo and is a part of the larger tri-university consortium of the Pacific Islands Climate Adaptation Science Center (PI-CASC).