中國稻鱼共生系统
作者：魏存争
浙江青田"稻魚共生系統"歷史悠久，延續了1200年，2005年被聯合國列入"globally important agricultural heritage systems, GIAHS"。浙江大學陳欣教授研究團隊經過6年的試驗研究，揭示物種間的正相互作用及資源的互補利用是稻魚共生系統可持續的重要生態學機制。
Ecological mechanisms underlying the sustainability of the agricultural heritage rice–fish coculture system
Jian Xie, Liangliang Hu, Jianjun Tang, Xue Wu, Nana Li, Yongge Yuan, Haishui Yang, Jiaen Zhang, Shiming Luo and Xin Chen*. 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.
“稻魚共生系統”中鯉魚通過衝撞稻秧，導致rice planthopper（昆蟲綱同翅目飛蝨科害蟲，俗名火蠓蟲）落入水中，降低其對水稻危害，研究人員通過錄像和控制實驗詳細重現了此過程。同時，鯉魚衝撞能夠使清晨水稻葉片露水墜入水中，減少稻瘟病原孢子產生和菌絲體生長，降低其對水稻危害。同時鯉魚取食甚至連根拔起許多雜草，顯著降低稻田雜草數量。
作為回報，水稻再給魚類提供食物（昆蟲和水稻葉片）的同時，還能夠抵擋烈日照射，降低表層水溫，除此之外，水稻能夠利用氮素，降低水中銨鹽濃度，為魚類生長創造良好環境。
相比常規水稻單作模式，稻魚共生系統能夠降低68的殺蟲劑和24的化肥施用。
和傳統水稻田一樣，稻魚共生系統面臨甲烷排放的困擾，尤其水淹時間延長，其排放量可能有贈無減。但是化肥施用量的減少，能夠降低另一重要溫室氣體-氧化亞氮的排放。同時，為降低農業生產中的氮素過量施用提供了很好的解決方法。
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.
總之，陳欣教授的研究成果為綠色水稻生產提供了好的模式，將中國幾千年來勤勞、淳樸而又充滿大智慧的農民推到世界科學的前沿。 PNAS同期刊發了亞利桑那大學Lansing的評論，稱其利用傳統混作農業中的生態遺產為我們上了一堂可持續農業課，推動了生態農業發展。
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.
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