|WALDRIP, HEIDI - University Of Maine|
|ERICH, M SUSAN - University Of Maine|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 6/28/2010
Publication Date: 8/9/2010
Citation: Waldrip, H.M., He, Z., Erich, M., Honeycutt, C.W. 2010. Effects of poultry manure on phosphorus availability to perennial ryegrass. American Society of Agronomy Meetings. Available: http://a-c-s.confex.com/crops/2010am/webprogram/Paper58566.html.
Technical Abstract: Soil phosphorus (P) exists in numerous forms that differ in plant availability. High-P organic fertilizers, including poultry manure (PM), can alter the balance of these soil P forms and may affect plant nutrient status. To investigate the effects of PM on soil P distribution and plant utilization we conducted a greenhouse study with perennial ryegrass (Lolium perenne) in soil amended with PM to provide P at rates of 0, 22, or 112 mg/kg. Pots were destructively harvested at 4, 8, and 16 weeks, with soil separated into rhizosphere and bulk fractions and sequentially extracted with H2O, 0.5 M NaHCO3, 0.1 M NaOH, and 1.0 M HCl followed by analysis for inorganic P (Pi) and enzymatically hydrolysable organic P (Poe). PM at 112 mg P / kg increased P uptake by ryegrass, with higher shoot biomass and root P concentrations than unamended soil. PM affected extractable soil Pi and Poe by increasing labile-Pi (H2O and NaHCO3-extracts) and lowering NaOH- and HCl-Poe. Furthermore, soil P distribution differed with proximity to plant roots, as the rhizosphere was higher in total extractable-Pi and NaOH-Pi at 16 weeks with PM than bulk soil. In addition, organic P fractions were affected, as rhizosphere soil had lower total extractable- and NaOH-Poe than bulk soil at 4 weeks, while HCl-Poe was higher and increased over time with all treatments. These results demonstrate that poultry manure can induce changes in specific soil P fractions and may promote plant utilization of less-labile P.