COVER CROP RESEARCH

Cover crop field trial.
Roller crimper in a no-till system with sunn hemp cover crop.
Learning how to use the cover crop calculator.
Cover crops (left to right) cowpea, woolly pod vetch, sunn hemp with a black oat border.
Talking about cover crops at the Urban Garden Center.
Brainstorming research ideas

Projects

1) Wang, K.-H., J. Bloese, J. Uyeda, J. Silva, H. Lutgen, K. Tavares, R. Manandhar. 2023-2028. Regenerating Soil Health through Shelterbelt Planting, Sheet Mulching and Tree Mulch Plant-Available Nitrogen Calculator. NRCS OnFarm Trial. NR233A750011G011

Shelter Belt Trees for Cacao Pollination

2) Wang, K.-H., J. Uyeda, J. Silva, D. Elliot, T. Radovich. 2022. Western Cover Crop Council Outreach Grant. U.S. USDA NIFA 2018-38640-28418 through Western SARE (WESP 19-01).

3) Wang, K.-H., K. Lawrence, B. S. Sipes, E. Sikora, Z. Cheng, R. Myers, R. Manandhar, J. Uyeda, S. Marahatta. 2021-2024. Organic sweetpotato IPM and soil health management for small- and mid-size farms. NIFA OREI (HAW09705-G).

4) Wang, K-H., J. Silva, and J. Uyeda. 2021-2023. Cover crop mix for orchard or trellis fruit and vegetable crops: Better soil health and weed management in Hawaii. NRCS CIG PIA (NR2192510002G002).

5) Wang, K.-H., J. Silva, and J. Hawkins. 2019-2021. Finding new friends for sunn hemp to revitalize degraded soil in the tropic. NRCS CIG PIA (NR1992510002G001).

6) Waisen, P. and K.-H. Wang. 2017-2019. “Cover Crop 5-in 1 Approach” for nematode management using mustard and oil radish. WSARE $25,000.

Biofumigation pamphlet

7) Wang, K.-H., Archana Pant, Jari Sugano, and Jensen Uyeda. 2015-2018. Improving water use efficiency through no-till cover cropping and solarization. NRCS CIG (Hawaii).

8) Wang, K.-H., T. Radovich, A. Pant, N. Andrew, N. Hue, J. Sugano and J. Uyeda. 2014-2017. Promoting the use of cover crop calculator for the tropics as nitrogen management tool and the use of cover crops for soil health management guideline. NRCS CIG (National).

Cover Crop Chart for Hawaii
Cover Crop Plant Available Nitrogen (PAN) calculator (~3.9 MB, pdf presentation)
Cover Crop Calculator (excel file, rev 3/11/2017)
Cover Crop Mix (pdf)
Cover crop calculator 2016 updates (~2 MB, pdf presentation)
Instructions to use cover crop calculator

9) Wang, K.-H., A. Pant, T. Radovich, J. Sugano, C. Tamaru, B. Fox, J. Uyeda, S. Chiang, C. Chan-Halbrandt. 2013-2016. Center of Rural Agriculture Training for Entrepreneurship (CRATE) for the Pacific. NIFA AFRI AE&RC

Effects of Surface Mulch on Soil Health Conditions in Conservation-Tillage Systems (~4.7 MB)

10) Wang, K.-H et al. 2013-2015. The influence of cover crops and tillage on soil quality, greenhouse gas emissions, pest community dynamics, and economics of fields transitioning to organic farming. NIFA ORG.

Contribution of no-till cover cropping to greenhouse gas remediation: Can nematodes tell the tale? (~2.8 MB)

11) Wang, K.-H., L. Kaufman, B.S. Sipes, T. Radovich, and J. Sugano. 2010-2012. An innovative cover cropping system for organic cucurbit growers in Hawaii: From nematode and pickleworm management, improvement of pollinator habitat to soil conservation. NRCS CIG.

Cover Cropping System & Compost Tea Treatment for Management of Nematodes, Whiteflies, and Pollinators (~1.5 MB)

12) Wang, K.-H., C.R.R. Hooks, B.S. Sipes, J. Sugano, and A. Arakaki. 2010-2012. Using conservation tillage and cover crop mixtures to enhance natural enemies of nematode pests. TSTAR.

Benenfits of Mix Cover Cropping on Soil Health (~2.8 MB)

Selected Publications

To access PDF files of my publications, please visit ResearchGate at http://www.researchgate.net/profile/Koon-Hui_Wang/publications

Paudel, R., Balkwill, L. and Wang, K.H., 2024. Allelopathic effects of sorghum/sorghum-sudangrass hybrids against Rotylenchulus reniformis. Plant Disease (https://doi.org/10.1094/PDIS-08-24-1668-RE)
Pitiki, M., Paudel, R., Mew, J. and Wang, K.H., 2024. Examining susceptibility of white clover, buckwheat, black oat, and forage radish as a long-term cover crop mix to Meloidogyne incognita. Nematropica 54. (https://journals.flvc.org/nematropica/article/view/135613)
Wang, K.-H. P. Waisen, R. Paudel, G. Chen, S.L.F. Meyer and C.R.R. Hooks. 2022. Effects of plasticulture and conservation tillage on nematode assemblage and their relationships with nitrous oxide emission following a winter cover cropping and vegetable production system. Horticulturae 8: 728. https://doi.org/10.3390/horticulturae8080728.
Marquez, J., R. Paudel, B. S. Sipes, and Koon-Hui Wang. 2022. Successional effects of no-till cover cropping with black oat ( Avena olariza) vs. soil solarization on soil health in a tropical Oxisol. Horticulturae 8: 527 (https://doi.org/10.3390/horticulturae8060527).
Wang, K.-H., P. Waisen, A. W. Leslie, R. Paudel, S.L.F. Meyer and C.R.R. Hooks. 2022. Relationships between soil tillage systems, nematode communities and weed seed predation. Horticulturae 8: 425. https://doi.org/10.3390/horticulturae8050425.
Paudel, R., P. Waisen, and K.-H. Wang. 2021. Exploiting the innate potential of sorghum/sorghum–sudangrass cover crops to improve soil microbial profile that can lead to suppression of plant-parasitic nematodes. MDPI-Microorganisms 9:1831 https://doi.org/10.3390/microorganisms9091831
Manandhar, R., K.-H. Wang, C. R.R. Hooks, and M. Wright. 2017. Effects of strip-tilled cover cropping on the population density of thrips and predatory insects in a cucurbit agroecosystem. Journal of Asia-Pacific Entomology 192_R1.
Kokalis-Burelle, N., R. McSorley, K.-H. Wang, S. Saha, R. McGovern. 2017. Rhizosphere microorganisms affected by soil solarization and cover cropping in Capsicum annuum and Phaseolus lunatus agroecosystems. Applied Soil Ecology 119: 64-71.
Leslie, A., K.-H. Wang, S. Meyer, C. R.R. 2017. Hooks. Influence of cover crops on arthropods, free-living nematodes, and yield in a succeeding no-till soybean crop. Applied Soil Ecology 117-118: 21-31.
Quintanilla-Tornel, M.A., K.-H. Wang, J. Tavares, C.R.R. Hooks. 2016. Effects of mulching on above and below ground pests and beneficials in a green onion agroecosystem. Agriculture, Ecosystems, & Environment 224: 75-85.
Hinds, J., K.-H. Wang, and C. R.R. Hooks. 2015. Growth and yield of zucchini squash (Cucurbita pepo L.) as influenced by a sunn hemp living mulch. Biological Agriculture & Horticulture. 13 pp. DOI: 10.1080/01448765.2015.1017736.
Wang, K.-H., T. Radovich, A. Pant, and Z. Cheng. 2014. Integration of cover crops and vermicompost tea for soil and plant health management in a short-term vegetable cropping system. Applied Soil Ecology 82: 26-37. DOI: 10.1016/j.apsoil.2014.05.003
Hinds, J., K.-H. Wang, S. P. Marahatta, S. L.F. Meyer, and C. R.R. Hooks. 2013. Investigating the influence of sunn hemp cover cropping and organic fertilizer on the nematode community in a zucchini cropping system. Journal of Nematology 45: 265-271.
Marahatta, S.P., K.-H. Wang, B.S. Sipes, and C.R.R. Hooks. 2012. Effects of Tagetes patula on active and inactive stages of root-knot nematodes. Journal of Nematology 44: 26-30.
Marahatta, S. P., K.-H. Wang, B.S. Sipes, and C.R.R. Hooks. 2012. Effects of the integration of sunn hemp and soil solarization on plant-parasitic and free-living nematodes. Journal of Nematology 44: 72-79.
Marahatta, S. P., K.-H. Wang, B.S. Sipes, and C.R.R. Hooks. 2012. Effects of Crotalaria juncea on anhydrobiotic state of Rotylenchulus reniformis. Nematropica 42: 34-40.
Hooks,C. R.R., K.-H. Wang, S.L.F. Meyer, M. Lekveishvili, J. Hinds, E. Zobel, A. Rosario-Lebron, and M. Lee-Bullock. 2011. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes. Journal of Nematology 43: 166-175.
Wang, K.-H., C.R.R. Hooks, and S.P. Marahatta. 2011. Can using a strip-tilled living mulch system enhance organisms higher up in the soil food web hierarchy? Applied Soil Ecology 49:107-117(doi:10.1016/j.apsoil.2011.06.008 ).
Hooks, C.R.R., K.-H. Wang, A. Ploeg, R. McSorley. 2010. Using marigold (Tagetes spp.) as a cover crop to protect crops from plant-parasitic nematodes. Applied Soil Ecology 46: 307-320.
Wang, K.-H., B.S. Sipes, and C.R.R. Hooks. 2011. Sunn hemp cover cropping and solarization as alternatives to soil fumigants for pineapple production. Acta Hort (ISHS) 902: 221-232. http://www.actahort.org/books/902/902_22.htm
Marahatta, S. P., K.-H. Wang, B.S. Sipes, and C.R.R. Hooks. 2010. Strip-till cover cropping for managing nematodes, soil microarthropods and weeds in a bitter melon agroecosystem. Journal of Nematology 42: 111-119.
Wang, K.-H., R. McSorley, R. N.Gallaher, N. Kokalis-Burelle. 2008. Cover crops and organic mulches for nematode, weed, and plant health management. Nematology 10: 231-242.
Wang, K.-H., R. McSorley, N. Kokalis-Burelle. 2006. Effects of cover cropping, solarization, and soil fumigation on nematode communities. Plant and Soil 286: 229-243.
Wang, K.-H., R. McSorley, A. J. Marshall, and R. N. Gallaher. 2004. Nematode community changes following decomposition of Crotalaria juncea amendment in litterbags. Appl. Soil Ecology 27:31-45.
Wang, K.-H., R. McSorley, R. N. Gallaher. 2004. Effect of Crotalaria juncea amendment on squash infected with Meloidogyne incognita. J. Nematol. 36: 290-296.
Wang, K.-H., R. McSorley, R. N. Gallaher. 2004. Relationship of soil management history and nutrient status to nematode community structure. Nematropica 34: 83-95.
Wang, K.-H., R. McSorley, R. N. Gallaher. 2003. Effect of Crotalaria juncea amendment on nematode communities in soil with different agricultural histories. J. Nematol. 35: 294-301.
Wang, K.-H., B. S. Sipes, and D. P. Schmitt. 2003. Intercropping cover crops with pineapple for the management of Rotylenchulus reniformis and Meloidogyne javanica. J Nematol. 35: 30-47.
Wang, K.-H., B. S. Sipes, and D. P. Schmitt. 2002. Crotalaria juncea as a cover crop for nematode management: A review. Nematropica 32: 35-57.
Wang, K.-H., B. S. Sipes, and D. P. Schmitt. 2003. Suppression of Rotylenchulus reniformis enhanced by Crotalaria juncea amendment in pineapple field soil. Agri. Eco. Environ. 94: 197-203.
Wang, K.-H., B. S. Sipes, and D. P. Schmitt. 2002. Management of Rotylenchulus reniformis in pineapple, Ananas comosus, by intercycle cover crops. J. Nematol. 34: 106-114.
Wang, K.-H., B. S. Sipes, and D. P. Schmitt. 2001. Suppression of Rotylenchulus reniformis by Crotalaria juncea, Brassica napus, and Tagetes erecta. Nematropica 31(2): 235-249.

Newsletters

Wang, K.-H., R. Paudel, J. Mew, and J. Silva. 2023. Akamai Cover Crop Mix (White clover, buckwheat, black oat): Does it benefit soil health? HānaiʻAi 52: December, 2023. https://gms.ctahr.hawaii.edu/gs/handler/getmedia.ashx?moid=72369&dt=3&g=12
Pitiki, M., B. Wiseman, L. Wong, B. Sipes, J. Silva, J. Uyeda, R. Mandhar and K.-H. Wang. 2023. Sustainable Pest and Soil Health Management for Sweet Potato Production. HānaiʻAi 51: September 2023. https://gms.ctahr.hawaii.edu/gs/handler/getmedia.ashx?moid=72226&dt=3&g=12
Wang, K.-H., and B. S. Sipes. 2023. Prescription for soil health by cover cropping in Hawaii: for annual cropping systems. HānaiʻAi 50: June 2023. https://gms.ctahr.hawaii.edu/gs/handler/getmedia.ashx?moid=72134&dt=3&g=1
Wang, K.-H., J. Mew and J. Silva. 2023. Akamai cover crop mix: How to establish? Partial cost analysis and its benefits. HānaiʻAi 49: March 2023. https://gms.ctahr.hawaii.edu/gs/handler/getmedia.ashx?moid=72076&dt=3&g=12
Paudel, R., L. Braley, Joshua Silva and K.-H. Wang. 2022. Subbing sunn hemp with sorghum in Fusarium soils. HānaiʻAi 48: Newsletter December 2022. 8 pp. https://gms.ctahr.hawaii.edu/gs/handler/getmedia.ashx?moid=71763&dt=3&g=12
Catherman, H., K.-H. Wang, R. Paudel, S. Budhathoki, and C. Mogren. 2021. Pigeon pea: A multipurpose N-fixing border crop. https://myemail.constantcontact.com/The-Latest-H-nai-Ai-News---April---May---June-2021-Volume-42.html?soid=1102675671876&aid=F9Y1OK_qJKk
Paudel, R., S. Budhathoki, and K.-H. Wang. 2021. Revitalized degraded soil in the tropic with energy sorghum. HānaiʻAi 42. https://myemail.constantcontact.com/The-Latest-H-nai-Ai-News---April---May---June-2021-Volume-42.html?soid=1102675671876&aid=F9Y1OK_qJKk.
Waisen, P., R. Paudel, and K.-H. Wang. 2020. An Update on Biofumigation Research in Hawaii: The equipment matters! HānaiʻAi Newsletter March-May, 2020.
Waisen, P. and Wang, K.-H. 2019. What plastic mulch can help biofumigation to better manage nematodes? HānaiʻAi Newsletter September 2019.
Waisen, P. and Wang, K.-H. 2018. Trap cropping and biofumigation for plant-parasitic nematode management. HānaiʻAi Newsletter March, April, May 2018.
Ching, S., K.-H. Wang, and J. Uyeda. 2017. Drop Spreader Calibration using the 10/160th Method. HānaiʻAi Newsletter March-April-May 2017.
Marquez, J., K. Matsuda, and K.-H. Wang. 2016. Improving Conservation Tillage with Conservation Agriculture Practices. Hānai‘Ai Newsletter June/July/Aug 2016.
Wang, K.H., I.A. Zasada, and B.S. Sipes. The Secret of the Allelopathic Effect of Sunn Hemp for Suppressing Plant-parasitic Nematodes. Hānai‘Ai Newsletter June-July-August 2012.
Wang, K.H. Cover crops as insectary plants to enhance above and below ground beneficial organisms. Hānai‘Ai Newsletter March-April-May 2012.
Wang, K.-H., B.S. Sipes, C.R.R. Hooks, and J. Leary. Improving the status of sunn hemp as a cover crop for soil health and pests management. Hānai‘Ai Newsletter Summer 2011. http://www.ctahr.hawaii.edu/sustainag/news/articles/V8-Wang-sunnhemp.pdf
Wang, K.-H., B.S. Sipes, and C.R.R. Hooks. Environmental friendly approaches for managing nematodes and weeds on pineapple. Pineapple News 17: 27-32. May 2010.
Wang, K.-H. Improving marigold cover cropping for nematode management. HānaiʻAi Newsletter Summer 2010. https://www.ctahr.hawaii.edu/sustainag/news/articles/V4-Wang-marigold.pdf
Wang, K.-H. Soil solarization and cover cropping as alternatives to soil fumigation for pineapple growers in Hawaii. HānaiʻAi Newsletter Spring 2010. http://www.ctahr.hawaii.edu /sustainag/news/articles/V3-Wang-SHPineapple.pdf
Wang, K.-H. and C.R.R. Hooks. Strip-till cover cropping and row switching techniques. HānaiʻAi Newsletter Winter 2009.
Wang, K.-H. and S. P. Marahatta. Improving sunn hemp benefits by integrating with solarization. HānaiʻAi Newsletter Fall 2009.

Extension Publications at CTAHR

Pant, A., T.J.K. Radovich, K.-H. Wang, N.V. Hue, M. Fergerstrom, R. Hamasaki, M. Wung, and C. Robb. 2015. Performance and plant-available nitrogen contribution of cover crops in high elevations in Hawai‘i. CTAHR Cooperative Extension Service SA-15. 8 pp. http://www.ctahr.hawaii.edu/oc/freepubs/pdf/SA-15.pdf
Wang. K.-H. and B.S. Sipes. 2009. Solarization and Cover Cropping as Alternatives to Soil Fumigants for Nematode Management in Hawai‘i’s Pineapple Fields. CTAHR Cooperative Extension Service SCM-29. 4 pp. http://www.ctahr.hawaii.edu/oc/freepubs/pdf/SCM-29.pdf
Hooks, C.R.R., K. Chandara, D.Fallon, K.-H. Wang, R. Manandhar. 2007. The impact of sunn hemp cover cropping on belowground organisms and nutrient status associated with a cucumber planting. Cooperative Extension Service SCM-21. http://www.ctahr.hawaii.edu/oc/freepubs/pdf/SCM-21.pdf
Wang, K-H., C. R.R. Hooks, and Antoon Ploeg. 2007. Protecting crops from nematode pests: using marigold as an alternative to chemical nematicides. Cooperative Extension Service, CTAHR, PD-35. http://www.ctahr.hawaii.edu/oc/freepubs/pdf/PD-35.pdf
Hooks, C.R.R., A. Fereres, and K.-H. Wang. 2007. Using protector plants to guard crops from aphid caused non-persistent viruses. Cooperative Extension Service, CTAHR SCM-18. http://www.ctahr.hawaii.edu/oc/freepubs/pdf/SCM-18.pdf

Videos

Wang, K.-H. and C.R.R. Hooks. 2008. Sunn hemp as a superhero: Sunn hemp for nematode and soil health management. Western region SARE, University of Hawaii, CTAHR, Honolulu, HI. https://youtu.be/AG_CYsVmqN4
Sugano, J. 2017. Cover Crop Calculator Field day. University of Hawaii, CTAHR, Honolulu, HI. https://youtu.be/ES8zn_c9Bzw

Presentations

Using Cover Crops/Insectary Plants to Enhance Above and Below Ground Beneficial Organisms (~ 18 MB)
Cover Crop Lectures (Part I, Part II, Part III)

Poster

Wang, K.-H. and A. Pant. 2015. Cover Crop Chart for Hawaii.

Procedure for sunn hemp strip till cover cropping.

1. Plant sunn hemp in rows for 2-3 months.
2. Cut down alternate rows of sunn hemp.
3. Till in alternate rows of sunn hemp.
4. Transplant cucumber seedlings, trim sunn hemp living mulch.
5. Trim sunn hemp living mulch once a month and use as surface mulch.
6. Sunn hemp is easier mowed by flail mower.
7. Close up of flail mower.
8. Flail mowed sunn hemp residues.
9. Sunn hemp could also be mulched down using roller crimper.