fertilizer definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a person or thing that fertilizes; specif., any material, as manure, chemicals, etc., put on or in the soil to improve the quality or quantity of plant growth
fertilizer definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Any of a large number of natural and synthetic materials, including manure and nitrogen, phosphorus, and potassium compounds, spread on or worked into soil to increase its capacity to support plant growth.
fertilizer - Science Definition
Any of a large number of natural and synthetic materials, including manure and compounds containing nitrogen, phosphorus, and potassium, spread on or worked into soil to increase its capacity to support plant growth. Synthetic fertilizers can greatly increase the productivity of soil but have high energy costs, since fossil fuels are required as a source of hydrogen, which is necessary to fix nitrogen in ammonia.