Can Albizia Compost Applied to Crops Replace Fertilizer, Improve Agroecosystem Functioning, and Provide Climate Change Mitigation and Resilience?
Joanna Norton (1), Rebecca Ostertag (1), Bruce Mathews (1), Springer Kaye (2) 1-University of Hawai'i, Hilo 2- Big Island Invasive Species Committee
*Invasive Species:
- Invasive plants such as albizia (Falcataria moluccana) fix atmospheric carbon and nitrogen (4,6)
- also create hazards and displace native plants (4)
*Agriculture:
- demand for food grows as arable land becomes degraded and less available (10)
- typical commercial farming releases GHG's through fertilizer production and tilling of soil (5,8)
*Climate Change
- agriculture and forestry account for 25% of global GHG emissions (3)
- climate change will affect agriculture with flooding, heat waves, drought, and shifting biomes (1,3)
- soil carbon is depleted worldwide, can be restored with climate-smart ag methods (i.e. composting) (2,5,8,9)
Three related problems....
*Invasive Species:
- Invasive plants such as albizia (Falcataria moluccana) fix atmospheric carbon and nitrogen (4,6)
- also create hazards and displace native plants (4)
*Agriculture:
- demand for food grows as arable land becomes degraded and less available (10)
- typical commercial farming releases GHG's through fertilizer production and tilling of soil (5,8)
*Climate Change
- agriculture and forestry account for 25% of global GHG emissions (3)
- climate change will affect agriculture with flooding, heat waves, drought, and shifting biomes (1,3)
- soil carbon is depleted worldwide, can be restored with climate-smart ag methods (i.e. composting) (2,5,8,9)
--a traditional farming method practiced locally and in subsistence farming around the world, the idea for this research began with local farmers
--Invasive species managers, including BIISC (Big Island Invasive Species Committee) are looking for economic uses for albizia to encourage more widespread control activities and support this research
--local citizens and the State of Hawai'i are seeking to increase local food production and decrease Hawai'i's carbon footprint. Alternative methods need to be tested and improved upon in the local environment.
Community and stakeholders
--a traditional farming method practiced locally and in subsistence farming around the world, the idea for this research began with local farmers
--Invasive species managers, including BIISC (Big Island Invasive Species Committee) are looking for economic uses for albizia to encourage more widespread control activities and support this research
--local citizens and the State of Hawai'i are seeking to increase local food production and decrease Hawai'i's carbon footprint. Alternative methods need to be tested and improved upon in the local environment.
In this method, composted albizia provides organic matter (C and N) to cropland, replacing fertilizer.
-- albizia forests are spreading across Hawaii, an economic use could stimulate removal of the living trees and protect forests
--soil is a large carbon pool, larger than the atmospheric and biotic pools combined. Cropland is generally depleted of carbon , so it is a ready sink for more carbon storage. (5,7,9)
--To lower GHG emissions, activities must be redesigned with a lower carbon footprint. Agriculture is the most direct and widespread way in which humans interact with the soil and biotic carbon pools. Alternative or traditional farming methods that return organic matter to the soil can sequester soil carbon and protect against climate extremes (drought, flooding, heat). (2,3,5,8)
--Nitrogen-rich additions to the soil, in particular, can increase soil carbon storage by stimulating growth in both the plants and microbes present (1,2)
... one possible solution?
In this method, composted albizia provides organic matter (C and N) to cropland, replacing fertilizer.
-- albizia forests are spreading across Hawaii, an economic use could stimulate removal of the living trees and protect forests
--soil is a large carbon pool, larger than the atmospheric and biotic pools combined. Cropland is generally depleted of carbon , so it is a ready sink for more carbon storage. (5,7,9)
--To lower GHG emissions, activities must be redesigned with a lower carbon footprint. Agriculture is the most direct and widespread way in which humans interact with the soil and biotic carbon pools. Alternative or traditional farming methods that return organic matter to the soil can sequester soil carbon and protect against climate extremes (drought, flooding, heat). (2,3,5,8)
--Nitrogen-rich additions to the soil, in particular, can increase soil carbon storage by stimulating growth in both the plants and microbes present (1,2)
-- Albizia compost collected and aged over one year
-- Two crops: cassava (Manihot esculenta) and corn (Zea mays)
-- Six treatment levels, shown in grid above
-- Response variables measured at harvest
-- soil nutrients (carbon, nitrogen, phosphorous, potassium, etc.)
-- plant tissue nutrients
-- yields of harvested crops
-- water holding capacity
Methods
-- Albizia compost collected and aged over one year
-- Two crops: cassava (Manihot esculenta) and corn (Zea mays)
-- Six treatment levels, shown in grid above
-- Response variables measured at harvest
-- soil nutrients (carbon, nitrogen, phosphorous, potassium, etc.)
-- plant tissue nutrients
-- yields of harvested crops
-- water holding capacity
Top row: corn at 1 1/2 months old
Bottom row: cassava at 6 months old
Each color on measuring stick indicates one foot length
Growth of crops mid-season
Top row: corn at 1 1/2 months old
Bottom row: cassava at 6 months old
Each color on measuring stick indicates one foot length
Crops are currently growing, see photos in lower box
A comparison of costs and carbon use efficiency per yield will be presented
Results
Crops are currently growing, see photos in lower box
A comparison of costs and carbon use efficiency per yield will be presented
-- If yields of alternative method = or > yields of fertilized control: this method could be viable alternative
-- If yields < but carbon storage or other benefits >, farmers make a choice between maximizing short term yields and improving soil health
-- If yields < and carbon storage or other benefits <, this is not an adequate alternative by itself, other methods should be tested
Acknowledgements
▪Professors Becky Ostertag, Bruce Mathews, and Flint Hughes
▪ Big Island Invasive Species Committee (BIISC) and Springer Kaye
▪ The farmers, landowners, and helpers in the field that are helping make this project happen
▪ Pacific Island Climate Adaptation Science Center (PICASC), for support of this project through the UHH-Manager Climate Corps Program
note: all photos without other notation are taken by Joanna Norton
References
- 1. Cusack, D. F., M. S. Torn, W. H. McDowell, and W. L. Silver. 2010. The response of heterotrophic activity and carbon cycling to nitrogen additions and warming in two tropical soils. Global Change Biology 16:2555–2572.
- 2. Drinkwater, L. E., P. Wagoner, and M. Sarrantonio. 1998. Legume-based cropping systems have reduced carbon and nitrogen losses. Nature 396:262–265.
- 3. Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L. L. W. eds. . 2014. IPCC 2014, Summary for Policymakers. Cambridge, United Kingdom and New York, NY, USA.
- 4. Hughes, R. F., and J. S. Denslow. 2005. Invasion by a N2-fixing tree alters function and structure in wet lowland forests of Hawaii. Ecological Applications 15:1615–1628.
- 5. Lal, R. 2004. Soil carbon sequestration to mitigate climate change. Geoderma 123:1–22.
- 6. Resh, S. C., D. Binkley, and J. A. Parrotta. 2002. Soil carbon sequestration under nitrogen-fixing trees compared with Eucalyptus species. Ecosystems 5:217–231.
- 7. Six, J., R. T. Conant, E. A. Paul, and K. Paustian. 2002. Stabilization mechanisms of soil organic matter: Implications for C-saturation of soils. Plant and Soil 241:155–176.
- 8. Steenwerth, K. L. et al. 2014. Climate-smart agriculture global research agenda: scientific basis for action. Agriculture & Food Security 3:11.
- 9. Stewart, C. E., K. Paustian, R. T. Conant, F. Plante, and J. Six. 2008. Soil carbon saturation: Evaluation and corroboration by long-term incubations. Soil Biology & Biochemistry 40:1741–1750.
- 10. Vitousek, P. M., H.A. Mooney, J. Lubchenco, and J. M. Melillo. 1997. Human Domination of Earth’ s Ecosystems. Science 277:494–499.
Implications
-- If yields of alternative method = or > yields of fertilized control: this method could be viable alternative
-- If yields < but carbon storage or other benefits >, farmers make a choice between maximizing short term yields and improving soil health
-- If yields < and carbon storage or other benefits <, this is not an adequate alternative by itself, other methods should be tested
Acknowledgements
▪Professors Becky Ostertag, Bruce Mathews, and Flint Hughes
▪ Big Island Invasive Species Committee (BIISC) and Springer Kaye
▪ The farmers, landowners, and helpers in the field that are helping make this project happen
▪ Pacific Island Climate Adaptation Science Center (PICASC), for support of this project through the UHH-Manager Climate Corps Program
note: all photos without other notation are taken by Joanna Norton
References
- 1. Cusack, D. F., M. S. Torn, W. H. McDowell, and W. L. Silver. 2010. The response of heterotrophic activity and carbon cycling to nitrogen additions and warming in two tropical soils. Global Change Biology 16:2555–2572.
- 2. Drinkwater, L. E., P. Wagoner, and M. Sarrantonio. 1998. Legume-based cropping systems have reduced carbon and nitrogen losses. Nature 396:262–265.
- 3. Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L. L. W. eds. . 2014. IPCC 2014, Summary for Policymakers. Cambridge, United Kingdom and New York, NY, USA.
- 4. Hughes, R. F., and J. S. Denslow. 2005. Invasion by a N2-fixing tree alters function and structure in wet lowland forests of Hawaii. Ecological Applications 15:1615–1628.
- 5. Lal, R. 2004. Soil carbon sequestration to mitigate climate change. Geoderma 123:1–22.
- 6. Resh, S. C., D. Binkley, and J. A. Parrotta. 2002. Soil carbon sequestration under nitrogen-fixing trees compared with Eucalyptus species. Ecosystems 5:217–231.
- 7. Six, J., R. T. Conant, E. A. Paul, and K. Paustian. 2002. Stabilization mechanisms of soil organic matter: Implications for C-saturation of soils. Plant and Soil 241:155–176.
- 8. Steenwerth, K. L. et al. 2014. Climate-smart agriculture global research agenda: scientific basis for action. Agriculture & Food Security 3:11.
- 9. Stewart, C. E., K. Paustian, R. T. Conant, F. Plante, and J. Six. 2008. Soil carbon saturation: Evaluation and corroboration by long-term incubations. Soil Biology & Biochemistry 40:1741–1750.
- 10. Vitousek, P. M., H.A. Mooney, J. Lubchenco, and J. M. Melillo. 1997. Human Domination of Earth’ s Ecosystems. Science 277:494–499.
