Gain A Deeper Understanding Of Fertilizers
August 1, 2014 My first exposure to plant nutrition was in kindergarten. Miss Hatfield captured my 5-year-old attentive mind with stories of Native Americans teaching Pilgrims to put a fish in each planted hole with seed corn. The living parts of the soil would help convert the fish into food for the corn to eat through its roots. It made sense to me; the fish could be food for me, so why not for a tall, sturdy corn plant as well? I certainly didn’t know anything about N-P-K or such; that would come later.
Prior to the industrial revolution, traditional agriculture was productive using manures and nitrogen fixing cover crops to nourish plant growth. With scientific understanding, technological advances, and postwar excess stores of chemicals, synthetic fertilizers were born allowing more and less expensive food. With exponential population growth, food production was the highest and greatest use of the new discovery; ornamental landscape use followed with the 20th century suburban sprawl and middle class aesthetic standard of a manicured lawn.
Unfortunately, the modern concept of “if a little is good, more is better” prevailed in the residential use of fertilizer for landscapes. Not only does over fertilization attract plant pests – including insect pests and diseases – it contributes significantly to non-point source pollution of our surface and groundwater.
As of Jan. 1, 2014, it is law in the State of Florida that anyone that applies fertilizer commercially (for pay) must have earned the Limited Urban Fertilizer certificate after training in the Green Industries Best Management Practices of landscape maintenance to help protect our water resources. That certificate and the need to earn Continuing Education Units to keep it in effect are probably why you are reading this now.
There are many differences in fertilizers available for landscapes, and consideration is needed for many factors (including but not exclusively price) in determining a purchase and application. Become an educated consumer of this product. Now for the N-P-K and such; I’m fortunate to be faculty for UF/IFAS in Extension, supported by the research and publications produced by my University colleagues.
The majority of this “article” assignment for you is in several publications, links below. Although some are geared for agronomic crops, the fertilizer principles apply to landscape fertilizers as well. Please read each one thoroughly; the test will include some obscure but pertinent questions from all of these documents.
- http://edis.ifas.ufl.edu/ss527 Principles of Sound Fertilizer Recommendations
- http://edis.ifas.ufl.edu/ss170 The Florida Fertilizer Label
- http://edis.ifas.ufl.edu/ss457 Nitrogen Fertilizer Sources
- http://edis.ifas.ufl.edu/ep261 Fertilization of Field-grown and Landscape Palms in Florida
- http://edis.ifas.ufl.edu/hs1208 Understanding and Applying Chelated Fertilizers Effectively Based on Soil pH
- http://edis.ifas.ufl.edu/hs1227 Methods for Measuring Nitrogen Release from Controlled-Release Fertilizer Used for Vegetable Production
- http://edis.ifas.ufl.edu/mg457 Soils & Fertilizers for Master Gardeners: Glossary of Soil and Fertilizer Terms
- http://news.aces.illinois.edu/news/study-reveals-nitrogen-fertilizers-deplete-soil-organic-carbon
The research from the University of Illinois that suggests that prolonged use of synthetic nitrogen can alter and degrade the soil microbiology. Perhaps as we evolve into a more sustainable society, we will once again rely on manures and cover crops for the nutrients our aesthetic landscapes need, reducing the potential for storm water runoff and leaching pollution from synthetic fertilizers. From the past; a fish in the hole with a corn seed to the future; chickens and legumes in every yard … In the meantime, as a landscape professional, please work as an informed fertilizer applicator.