Combined use of Azolla and loach suppressed paddy weeds and increased organic rice yield: second season results

Weiguo Cheng, Miwa Takei, Chizuru Sato, Valensi Kautsar, Yuka Sasaki, Satoru Sato, Keitaro Tawaraya, Hironori Yasuda


Organic farming uses alternatives to agricultural chemicals such as synthetic fertilizers and pesticides. The primary challenge in organic rice farming is controlling weeds without using herbicides and improving rice yield without chemical fertilizers. In our previous paper entitled as combined use of Azolla and loach suppressed weed Monochoria vaginalis and increased rice yield without agrochemicals, we reported the first year rice growth season results from an in situ container experiment. The experiment was designed with 4 treatments—control (with neither Azolla nor loach), Azolla (Azolla alone), loach (loach alone), and Az+Lo (combined Azolla and loach)—with 3 replications each. The first year results showed that combined use of Azolla and loach was successful in weed suppression and increase in rice yield in 2012. In this paper, we report the second year results from the continuous container experiment in 2013. M.vaginalis emergences were very low in second year rice growth season on all treatments. Compared first year, the rice yields decreased in second year on all treatments due to different weather condition and with or without organic soybean oil cake application between two rice growth seasons. The second year results also showed the raising loach had a stronger effect to increase tiller and panicle numbers, and spikelet number per panicle, then improve rice yields to 2.3 times than control. The Azolla residues left from first year have weaker effect on rice growth and yield, but increase soil organic matter accumulation at second year. The two years study indicated that combined use of Azolla and loach can meet two of the greatest challenges in organic rice production: providing effective weed control and improving rice nutrition without agrochemicals.     


Azolla; Loach; Organic farming; Rice yield; Soil organic matter

Full Text:



Biswas, M., Sultana, S., Shimozawa, H., Nakagoshi, N., 2005. Effect of Azolla species on weed emergence in a rice paddy ecosystem. Weed Biol Manag. 5, 176–183.

Brown, M.E., Funk, C.C., 2008. Food security under climate change. Science 319, 580–581.

Cheng, W., Sakai, H., Yagi, K., Hasegawa, T. 2009. Interactions of elevated [CO2] and night temperature on rice growth and yield. Agr Forest Meteorol. 149, 51–58.

Cheng, W., Sakai, H., Matsushima, M., Yagi, K., Hasegawa, T., 2010. Response of the floating aquatic fern Azolla filiculoides to elevated CO2, temperature, and phosphorus levels. Hydrobiologia 656, 5–14.

Cheng, W., Okamoto, Y., Takei, M., Tawaraya, K., Yasuda, H., 2015. Combined use of Azolla and loach suppressed weed Monochoria vaginalis and increased rice yield without agrochemicals. Org Agr. 5, 1–10.

Datta, B.K., Nayak, D.R., Sinhababu, D.P., Adhya, T.K., 2009. Methane and nitrous oxide emissions from an integrated rainfed rice–fish farming system of Eastern India. Agr Ecosyst Environ. 129, 228–237.

De Macale, M.A.R., Vlek, P.L.G., 2004. The role of Azolla cover in improving the nitrogen use efficiency of lowland rice. Plant Soil 263, 311–321.

FAO, 2015. FAOSTAT database. (accessed February, 2015)

Gattinger, A., Muller, A., Haeni, M., Skinner, C., Fliessbach, A., Buchmann, N., Mäder, P., Stolze, M., Smith, P., Scialabba N.E., Niggli, U., 2012. Enhanced top soil carbon stocks under organic farming. Proc Natl Acad Sci USA 109, 18226–18231

Janiya, J.D., Moody, K., 1984. Use of Azolla to suppress weds in transplanted rice. Trop Pest Manag. 30, 1–6.

Kano, Y., Kawaguchi, Y., Yamashita, T., Shimatani, Y., 2010. Distribution of the oriental weather loach, Misgurnus anguillicaudatus, in paddy fields and its implications for conservation in Sado Island, Japan. Ichthyol Res. 57, 180–188.

Kobayashi, K., Okada, M., Kim, H.Y., Lieffering, M., Miura, S., Hasegawa, T., 2006. Paddy Rice Responses to Free-Air [CO2] Enrichment. In: Nösberger, J., S.P. Long, R.J. Norby, M. Stitt, G.R. Hendrey & H. Blum (eds), Managed ecosystems and CO2: case studies, processes, and perspectives. Springer, Berlin Heidelberg New York, (Ecological studies, vol. 187), pp. 87–104.

Lopes, A.R., Faria, C., Prieto-Fernández, A., Trasar-Cepeda, C., Manaia, C.M., Nunes, O.C., 2011. Comparative study of the microbial diversity of bulk paddy soil of 2 rice fields subjected to organic and conventional farming. Soil Biol Biochem. 43, 115–125.

Lu, J., Li, X., 2006. Review of rice–fish-farming systems in China – One of the Globally Important Ingenious Agricultural Heritage Systems (GIAHS). Aquaculture 260, 106–113.

Mandal, B., Vlek, P.L.G., Mandal, L.N., 1999. Beneficial effects of blue-green algae and Azolla, excluding supplying nitrogen, on wetland rice fields: a review. Biol Fert Soils 28, 329–342.

Matsushima, S., Tanaka, T., 1960. Analysis of developmental factors determining yields and its application to yield prediction and culture improvement of a lowland rice. IV. Early discrimination of non-fertilized rice-grains. Proc Jpn Crop Sci Soc. 28, 365–366 (in Japanese).

Sahoo, S.K., Datta, B.K., 1999. Weed control by Azolla in rice (Oryza sativa) fields of South 24-Parganas, West Bengal. Indian J Agr Sci. 69, 283–284.

Sahrawat,K.L., 2003. Organic matter accumulation in submerged soils. Adv Agr. 81, 169–201

Scialabba, N.E.H., Muller-Lindenlauf, M., 2010. Organic agriculture and climate change. Renew Agr Food Syst. 25, 158–169.

Seufert, V., Ramankutty, N., Foley, J., 2012. Comparing the yields of organic and conventional agriculture. Nature 485, 229–232.

Smil, V., Kobayashi, K., 2012. Japan’s dietary transition and its impacts. The MIT Press, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142 USA.

Tanaka, M., 1999. Influence of different aquatic habitats on distribution and population density of Misgurnus anguillicaudatus in paddy fields. Jpn J Ichthyol 46, 75–81 (In Japanese).

Tilman, D., Cassman, K.G., Matson, P.A., Naylor, R., Polasky, S., 2002. Agricultural sustainability and intensive production practices. Nature 418, 671–677.

Xie, J., Hu, L., Tang, J., Wu, X., Li, N., Yuan, Y., Yang, H., Zhang, J., Luo, S., Chen, X., 2011. Ecological mechanisms underlying the sustainability of the agricultural heritage rice–fish coculture system. Proc Natl Acad Sci USA 108, E1381–E1387.

Wagner, G.M., 1997. Azolla: A review of its biology and utilization. Bot Rev. 63, 1–26.

Watanabe, I., Liu, C.C., 1992. Improving nitrogen-fixing systems and integrating them into sustainable rice farming. Plant Soil 141, 57–67.

Watanabe, I., 2006. Whither Azolla use goes? Regulation by invasive alien species act. J Weed Sci Technol. 51, 178–184 (in Japanese).



  • There are currently no refbacks.

Creative Commons License Hasil gambar untuk crossref
Journal of Wetlands Environmental Management is licensed under a Creative Commons Attribution 4.0 International License. ISSN: 2354-5844 (print version) and 2477-5223 (electronic version). joomla site stats View My Stats