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Acta Prataculturae Sinica ›› 2015, Vol. 24 ›› Issue (8): 85-92.DOI: 10.11686/cyxb2015023

• Orginal Article • Previous Articles     Next Articles

Effect of different levels of N supply on P accumulation characteristics of a ‘mining ecotype’ of Pilea sinofasciata

YU Hong-Mei, LI Ting-Xuan*, ZHANG Xi-Zhou, ZHENG Zi-Cheng, YU Hai-Ying   

  1. College of Resources, Sichuan Agricultural University, Chengdu 611130, China
  • Online:2015-08-20 Published:2015-08-20

Abstract: Quantities of P fertilizer and organic fertilizer are supplied in agro-ecosystems to improve the soil available P content and maintain soil fertility, but ultimately resulting in P immobilization and accumulation in the soil. Phytoextraction is a practical method for recovering the excess P after soils have become enriched. In order to provide a theoretical basis for extracting excess P from soil to assist with prevention and control of non-point source pollution, it was necessary to determine the P accumulation characteristics of a ‘mining ecotype’ (ME) of Pilea sinofasciata. This material had previously been screened as showing promise for P extraction from enriched soil. The effects of different levels of nitrogen (N) supply (0, 70, 140, 210, 280, 350 mg N/kg) on plant growth and P accumulation characteristics in the ME of P. sinofasciata were analyzed,with a non-mining ecotype (NME) as contrast. All treatments had the same P supply (400 mg P/kg soil). Pot experiments were carried out in a greenhouse at Sichuan Agricultural University, Sichuan province, China in 2013. Key results were: 1)For both shoot and root biomass, P accumulation of P. sinofasciata significantly increased with increased N supply up to 140 mg/kg, and then decreased with additional N supply. Shoot P accumulation of the ME was maximized at 140 mg/kg N supply, and ME demonstrated greater shoot P accumulation (223.73 mg/plant) than the NME (159.79 mg/plant) under different rates of N supply. The bioaccumulation coefficient of the ME was more than 1, while translation rate was more than 50%, and as high as 71%-88%. 2) The activities of acid phosphatase and phytase in P. sinofasciata peaked at N application rates of 350 mg/kg and 140 mg/kg, respectively, and the activities of these two enzymes in the ME were markedly higher (P<0.05) than those in the NME, being increased by a factor of 1.22-1.67, and 1.02-1.07, respectively. In conclusion, the P. sinofasciata ME showed substantial P accumulation ability under N application rates of 70-210 mg/kg. Thus, P. sinofasciata is a good candidate species for P phytoextraction, with the best results obtained when N was added at 140 mg/kg soil.