Biosolids www.epa.gov/region08/water/npdes/biosolid.html

Container nursery crops www.cals.cornell.edu/dept/flori/growon/containr/index.html

Potash & Phosphate Institute www.ppi-ppic.org

Fertilizer recommendations for vegetables - Michigan State University Extension
http://www.msue.msu.edu/msue/imp/modaf/modaff.html

Fertilizer guide http://wwwagcomm.ads.orst.edu/AgComWebFile/EdMat/FG52.pdf

University of California Cooperative Extension – Tulare County grape publications www.ucce.tulare.ca.us/pubgrape/pubgrape.htm#Nutrition

Sustainable Agriculture Research and Education Program (SAREP) www.sarep.ucdavis.edu

Sustainable Agriculture Farming Systems (SAFS) http://agronomy.ucdavis.edu/safs/home.htm