Lawn Talk  
   A range of lawn fertilizing articles beginning with "Choosing Fertilizers for Home Lawns".
   http://www.urbanext.uiuc.edu/lawntalk/lawntalk10.html

Island Lawn and Garden  
   Concise discussion about organic and inorganic fertilizing along with a number of lawn fertilization topics.
   http://www.ilg-mv.com/Pages/organicvs.html

Fertilizer Registration and Penalties  
   The North Carolina Department of Agriculture and Consumer Services offers advice on the fertilizer penalty system.
   http://www.agr.state.nc.us/plantind/fert/ferpenl.htm

Nitrogen Fertilizer: Ammonium Nitrate  
   Detailed chemical factsheet about the properties of ammonium nitrate.
   http://www.inform.umd.edu/EdRes/Topic/AgrEnv/ndd/agronomy/NITROGEN_FERTILIZER_AMMONIUM_NITRATE.html

Nitrogen Fertilizer: Ammonium Sulfate  
   Factsheet offering information about ammonium sulfate.
   http://www.inform.umd.edu/EdRes/Topic/AgrEnv/ndd/agronomy/NITROGEN_FERTILIZER_AMMONIUM_SULFATE.html

Nitrogen Fertilizer: Urea  
   Chemical information about the properties of urea.
   http://www.inform.umd.edu/EdRes/Topic/AgrEnv/ndd/agronomy/NITROGEN_FERTILIZER_UREA.html

Responsible Fertilizer Practices for Lawns  
   Outlines general fertilizer practices, nitrogen and phosphorus requirements, and application timing for lawns.
   http://www.extension.umn.edu/distribution/horticulture/DG6551.html

Nitrogen Fertilizer: Diammonium Phosphate  
   Factsheet about the chemical properties of diammonium phosphate.
   http://www.inform.umd.edu/EdRes/Topic/AgrEnv/ndd/agronomy/NITROGEN_FERTILIZER_DIAMMONIUM_PHOSPHATE.html

Soils and Soil Management  
   Offers a database and search function of a range of articles about fertilizers.
   http://www.msue.msu.edu/msue/imp/modf1/masterf1.html

Fertilizer Use and Abuse  
   Discusses the uses of fertilizers.
   http://royal.okanagan.bc.ca/mpidwirn/agriculture/fertilizer.html

Fertilization of Lawns  
   Details the benefits of and how to fertilize lawns.
   http://www.ag.ohio-state.edu/~ohioline/hyg-fact/4000/4006.html

MDS Harris Turf  
   A commercial soil-testing laboratory that provides soil and water testing as well as plant and tissue analysis for golf courses and athletic fields, as well as agronomic growers and dealers.
   http://www.turf.com

Fertilizer Use  
   Articles discussing the uses of fertilizer on certain types of plant (in pdf format).
   http://ipmwww.ncsu.edu/agchem/chptr10.html

Fertilizing Landscape Plants  
   Explains the necessities of fertilizing plants.
   http://www.ag.ohio-state.edu/~ohioline/hyg-fact/1000/1002.html

Fertilizing Woody Ornamentals  
   Explains the best way to fertilize these types of plants.
   http://aggie-horticulture.tamu.edu/extension/fertilizing/fertilizing.html

Extremely Green Gardening Company  
   Online source for organic gardening products including fertilizers, biological pest control, soil test kits.
   http://www.extremelygreen.com

University of Maine Bulletin  
   Information on fertilizers to supplement nutrients in the soil.
   http://www.umext.maine.edu/onlinepubs/htmpubs/LawnGarden/2287.htm

Fertilizers for Container Crops  
   Explains the basics for fertilizing certain types of potplants.
   http://www.umass.edu/umext/programs/agro/floriculture/floral_facts/fert.html

Convenience Fertilizers For Home Landscapes  
   Information on fertilizing shrubs and trees on home lanscapes.
   http://www.ext.vt.edu/departments/envirohort/factsheets2/fertilizer/sep90pr3.html

Fertilizer Application  
   Debates whether to fertilize with organic or inorganic products.
   http://gardenline.usask.ca/misc/fertili2.html

Washington State Department of Agriculture  
   Information on products and their content of heavy metals, along with fertilizer laws and label requirements.
   http://agr.wa.gov/