An Improved Understanding Of Phosphorus Dynamics And Fertility Management In Forage Production Systems

Forage fertility recommendations have not changed since the 1980s, and anecdotal evidence suggests producers often apply less than provincially recommended rates. A better understanding of forage fertility, especially phosphorus (P), is crucial to optimize profit and reduce environmental nutrient losses. This thesis explores how forage fertility affects productivity in two scenarios. First, a 14-week controlled environment study with Italian ryegrass (Lolium multiflorum) tested crop response to P addition in soils with different soil organic carbon (SOC) and agriculture land use histories. Crop yield was influenced by soil type and P supply rate (determined using anion exchange probes), but not by soil test P (Olsen P), suggesting SOC and phosphatase activities also impact P supply. In addition, a three-year field trial compared provincial soil test recommendations with light nutrient application (112 kg ha⁻¹ of 19-19-19 NPK fertilizer) across 19 forage types. Profitability increased with fertilization only in mixed grass-legume stands due to high nitrogen costs for grass-only stands. The overall findings highlight the importance of soil properties (e.g., SOC, enzymatic activity) and soil testing in increasing fertilizer use efficiency.

Grantor dc:publisher

University of Guelph

Author dc:creator

• Lamichhane, Puja

Advisor dc:contributor.advisor

• Schneider, Kimberley

• Phosphorus
• Soil organic matter
• Forage fertility

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc-nd/4.0/

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10214/28598

OAI record oai:identifier

https://atrium.lib.uoguelph.ca/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Aatrium.lib.uoguelph.ca%3A10214%2F28598