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Article
How do uncertain prices influence phosphorus and potassium fertilization this fall?
Integrated Crop Management News
  • Antonio P. Mallarino, Iowa State University
  • John E. Sawyer, Iowa State University
Document Type
Article
Publication Date
10-1-2007
Abstract
Crop prices and phosphorus (P) and potassium (K) fertilizer prices have changed significantly in the last two years, and there is considerable uncertainty about future prices. Profitable crop production requires appropriate soil P and K levels, so careful fertilization planning is required. Iowa State University (ISU) soil-test interpretations and fertilization guidelines in extension publication PM 1688, A General Guide for Crop Nutrient and Limestone Recommendations in Iowa (available to order or to download from www.extension.iastate.edu/pubs), were last updated in November 2002. Some important changes were to recommend higher soil-test K (STK) levels for all crops and to update default yield levels for calculating P and K fertilizer rates needed to maintain desirable soil-test levels.
Copyright Owner
Iowa State University
Language
en
File Format
application/pdf
Citation Information
Antonio P. Mallarino and John E. Sawyer. "How do uncertain prices influence phosphorus and potassium fertilization this fall?" (2007)
Available at: http://works.bepress.com/john-sawyer/97/