A traditional farming technique that cultivates rice and fish side-by-side could help small farmers earn more money from their crops and reduce the impact on the environment, according to a study. When fish were introduced into flooded paddy fields, farmers were able to grow the same amount of grain as in conventional rice monocultures — but with more than two-thirds less pesticide and a quarter less fertiliser, found a six-year long study conducted in China. These rice-fish co-cultures could lessen the environmental impact of agricultural chemicals and help make rice farming more profitable, said the study, published in the Proceedings of the National Academy of Science this week. Fish minimized the need for fertilizer. “In areas where land and water are limited for developing both rice and fish production, it is important to conduct RF rice-fish co-culture,” Xin Chen, lead author of the study and a professor at Zhejiang University, China, told SciDev.Net. She added that the technique should be combined with modern techniques such as irrigation, and the use of machinery. The fish used in the study were an indigenous carp species that is considered a delicacy, so farmers could sell them. They could also make large savings on fertilisers and pesticides, which typically represent 60–70 per cent of the total cost of rice production.
Nature
November 29, 2011
Original web page at Nature