“稻鸭共生”养分归还特征及水稻植株对氮、磷的吸收

Characteristics of nutrient return and uptake in rice-duck mutualism ecosystem of double rice cropping season

"稻鸭共生"是对我国传统农业稻田养鸭的继承与发展。在长江流域双季稻主产区湖南布置了稻田养鸭田间试验,以常规稻作为对照,研究早、晚稻两季"稻鸭共生"养分归还特征及对水稻植株氮、磷吸收的影响。结果表明:两季"稻鸭共生"后,稻田可增加鸭粪碳229.87 kg.hm 2、鸭粪氮18.22 kg.hm 2、鸭粪磷17.75 kg.hm 2。"稻鸭共生"归还稻田土壤的碳、氮、磷量分别为1 491.21 kg.hm 2、66.02 kg.hm 2、25.14 kg.hm 2,比常规稻作分别提高20.43%(P>0.05)、55.81%(P<0.05)、379.00%(P<0.05)。"稻鸭共生"归还稻田土壤的碳、氮、磷量表现为碳>氮>磷,归还的碳、氮量以水稻根碳、氮占明显优势,归还的磷量以鸭粪磷占明显优势。与常规稻作相比,土壤全氮含量提高5.73%,全磷含量显著提高6.25%;"稻鸭共生"提高了早、晚稻根和秸秆的全氮、全磷含量及早、晚稻籽粒的全磷含量,增加了早、晚稻秸秆的氮、磷吸收量和早、晚稻根的磷吸收量,降低了双季稻产量及籽粒的氮、磷积累量。"稻鸭共生"对水稻植株磷的影响效果好于氮。

Raising ducks in paddy fields is a traditional agricultural model in China.Field experiments were conducted in rice-duck mutualism ecosystems in the double rice cropping region of Hunan Province during May to October of 2010.A conventional rice field was used as the control.The characteristics of nutrient return and uptake by rice in the rice-duck mutualism ecosystem were analyzed.The main objectives of the study were to provide theoretical and practical bases for further development and utilization of this classical agricultural technique.Results showed that feeding duck in paddy fields respectively increased C,N and P by 229.87 kg·hm^- 2,18.22 kg·hm ^-2 and 17.75 kg·hm ^-2 of duck feces during double rice cropping season.During double rice cropping season,the return of C,N and P to soil in the rice-duck mutualism ecosystem was in the order of C 〉N 〉P.The measured values of C,N and P were 1 491.21 kg·hm 2,66.02 kg·hm 2 and 25.14 kg·hm 2,respectively.Compared with conventional rice cultivation system,the return of C,N and P into paddy soils under the rice-duck mutualism ecosystem increased by 20.43%（P 〈0.05）,55.81%（P 〈0.05） and 379%（P 〈0.05）,respectively.While C and N returns were largely from rice root system,P return was mostly from duck feces.In contrast with conventional rice system,rice-duck symbiosis system increased soil total N by 5.73%,significantly increased soil total P by 6.25%.The rice-duck symbiosis increased root and straw total N and P and seed total P during double cropping rice season.It also increased straw N and P uptake,root P uptake and decreased yield and seed N and P uptake during double cropping rice season.Rice P uptake and content were better than N under rice-duck mutualism ecosystem.