1. Virginia nutrient management standards and criteria. Richmond, VA.;Available from: (verified October,2005
2. Questions and answers regarding 3-nitro (Roxarsone). Available from: .;Accessed September,2011
3. Laboratory procedures: Virginia Tech Soil Testing Laboratory, Virginia Cooperative Extension, Blacksburg, VA.;Maguire;Available from Accessed September,2011
4. Maturity and quality of alfalfa as affected by phosphorus fertility.;Sanderson;Commun Soil Sci Plant Anal,1993