Soil phosphorus bioavailability as influenced by long-term management and applied phosphorus source

• Published in: Canadian Journal of Soil Science 2019-09, Vol.99 (3), p.292-304
• Main Authors: Fraser, Tandra D, Lynch, Derek H, O’Halloran, Ivan P, Voroney, R. Paul, Entz, Martin H, Dunfield, Kari E
• Format: Article
• Language: English
• Subjects: Absorption; Agronomy; apparent P use efficiency; assimilation apparente du P; Bioavailability; Composting; Culture; Fractionation; gestion à long terme; Lolium multiflorum; long-term management; Management systems; manure P; Manures; mineral P; P minéral; P organique; phosphore; Phosphorus; Plant growth; Seedlings; Sodium bicarbonate; Soils
• ISSN: 0008-4271; 1918-1841; 1918-1833
• DOI: 10.1139/cjss-2018-0075

Soil phosphorus (P) availability may be impacted by management practices, thereby affecting plant P uptake and plant response to P amendments. The aim of this study was to determine the effects of long-term management on soil P pools and to assess the response of P bioavailability, plant growth, and P uptake to mineral versus manure P treatments. Soils were collected from plots under organic (ORG), organic with composted manure (ORG + M), conventional (CONV), and restored prairie (PRA) management. Italian ryegrass (Lolium multiflorum L.) seedlings were grown in the greenhouse for 106 d in soils amended with various rates of manure or mineral P. The ORG soil had lower concentrations of labile P (resin-P and NaHCO3-P) compared with the CONV and PRA soils, as determined by sequential P fractionation prior to planting. Ryegrass biomass (root + shoot) and shoot P uptake from soils receiving no P were significantly lower for the ORG than all other management systems. Although apparent P use efficiency of the whole plant was increased by low P rate in the ORG management system, the source of applied P, manure > mineral, only influenced Olsen test P.