P accumulation of Polygonum hydropiper, soil P fractions and phosphatase activity as affected by swine manure

Animal manure is a good nutrient source for plant growth and the application of manure also affects rhizosphere processes. This study was conducted to investigate the effects of swine manure application on plant growth, P uptake, and rhizosphere characteristics of two ecotypes of Polygonum hydropiper. A mining ecotype (ME) and a non-mining ecotype (NME) were grown for 8 weeks in soils added with a series of swine manure (0-100 g kg (1)). In the study, plant P content and soil properties were analyzed. Biomass and P accumulation in P. hydropiper were significantly higher at 100 g kg (1) compared to the control. Besides, biomass and P accumulation of the ME were higher than the NME's. Swine manure application increased the levels of various P fractions. H2O-, NaHCO3- and NaOH-Pi (Pi, inorganic P) could be utilized efficiently by both ecotypes. Significant depletions of NaHCO3- and NaOH-Po (Po, organic P) were observed in the rhizosphere of the ME compared to the NME. No statistical changes of HCl- and residual-P were observed in the rhizosphere. Acid phosphatase and alkaline phosphatase activities were enhanced by both swine manure application and rhizosphere processes. In conclusion, P. hydropiper can utilize various P fractions from manure impacted soil and the ME shows a higher ability than the NME to mobilize Po. (C) 2014 Elsevier B.V. All rights reserved.