EPOW - Ecology Picture of the Week

Environmental Impacts of Rice Paddies

Rice Paddy
Dali Village, Yunnan, China

Explanation:  Much of the world relies on this globally staple crop:  rice, feeding more than half of the world's population.

Growing rice at this scale takes an enormous swath of Earth's land surface that must be contoured, watered, and tended to meticulously.  With such intensive agricultural effort, however, comes environmental impacts that are immensely difficult to avoid.

Grown in most countries of the world, rice cultivation produces a number of greenhouse gases including carbon dioxide, methane, nitrogen oxides, and others ...all of which contribute significantly to global warming and climate change (de Miranda et al. 2015).  

Most of the intensive rice cultivation efforts produce homogeneous environments with little secondary benefits such as providing habitat for wildlife except for occasional use by wetland species.  Rice cultivation has evolved largely to rely on artificially-produced chemical fertilizers.  Such intensively-tended rice fields are thus prime sources of disease outbreaks and the proliferation of undesirable insects and weeds, including in China (Luo et al. 2014). 

Approaches to reversing the adverse environmental impacts of rice paddies can include protecting surrounding environments, changing schedules and patterns of paddy cropping, reducing the use of chemical fertilizers and relying more on natural sources of nutrients and of pest control, and other means (Luo et al. 2014), including judicious water management with midseason drainage to reduce production of methane and nitrous oxides (Zou et al. 2005).  

   
Information:
     de Miranda, M.S., M.L. Fonseca, A. Lima, T.F. de Moraes, and F.A. Rodrigues.  2015.  Environmental impacts of rice cultivation.  American Journal of Plant Sciences 6(12):article ID 59054.
     Luo, Y., H. Fu, and S. Traore.  2014.  Biodiversity conservation in rice paddies in China: toward ecological sustainability.  Sustainability 6(9):6107-6124.
     Zou, J., Y. Huang, J. Jiang, X. Zheng, and R.L. Sass.  2005.  A 3-year field measurement of methane and nitrous oxide emissions from rice paddies in China: Effects of water regime, crop residue, and fertilizer application.  Global Biogeochemical Cycles 19(2):https://doi.org/10.1029/2004GB002401