Ecological mechanisms underlying the sustainability of the agricultural heritage rice–fish coculture system

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 108; no. 50; pp. E1381 - E1387
• Main Authors: Xie, Jian, Hu, Liangliang, Tang, Jianjun, Wu, Xue, Li, Nana, Yuan, Yongge, Yang, Haishui, Zhang, Jiaen, Luo, Shiming, Chen, Xin
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 13-12-2011; National Acad Sciences
• Series: PNAS Plus
• Subjects: Agriculture - methods; Animals; Biological Sciences; China; coculture; Conservation of Natural Resources; Ecological and Environmental Phenomena; ecosystems; Fertilizer application; Fertilizers; field experimentation; Fish; Fisheries - methods; Fishes - growth & development; Food supply; foods; grain yield; Insecta - physiology; livelihood; Nitrogen; Nitrogen - analysis; nitrogen fertilizers; Oryza - growth & development; Oryza sativa; Pest Control, Biological; Pesticides; pests; PNAS Plus; Quaternary Ammonium Compounds - analysis; Rice; Social Sciences; surveys; sustainability; Sustainable agriculture; Sustainable development; Temperature; Time Factors; traditional farming; Water; China; China, People's Rep
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1111043108

For centuries, traditional agricultural systems have contributed to food and livelihood security throughout the world. Recognizing the ecological legacy in the traditional agricultural systems may help us develop novel sustainable agriculture. We examine how rice–fish coculture (RF), which has been designated a "globally important agricultural heritage system," has been maintained for over 1,200 y in south China. A field survey demonstrated that although rice yield and rice-yield stability are similar in RF and rice monoculture (RM), RF requires 68% less pesticide and 24% less chemical fertilizer than RM. A field experiment confirmed this result. We documented that a mutually beneficial relationship between rice and fish develops in RF: Fish reduce rice pests and rice favors fish by moderating the water environment. This positive relationship between rice and fish reduces the need for pesticides in RF. Our results also indicate a complementary use of nitrogen (N) between rice and fish in RF, resulting in low N fertilizer application and low N release into the environment. These findings provide unique insights into how positive interactions and complementary use of resource between species generate emergent ecosystem properties and how modern agricultural systems might be improved by exploiting synergies between species.