Fertilization in Greenhouses: an
Introduction
Nutritional problems are among the most common
problems in greenhouses and can lead to serious economic losses. Plant growth can be reduced if plants get too
little or too much of certain nutrients.
Even the wrong balance among nutrients can cause serious problems. By the time that deficiency or toxicity
symptoms appear, plant growth often is severely compromised and correction of
the problems can be difficult and time-consuming. Suboptimal nutrition may even reduce plant
growth without ever causing any visible symptoms!
Since prevention is better than correction, it is
important to keep close track of your fertilization program. However, there are lots of confusing terms,
such as electrical conductivity, pH, alkalinity, and fertilizer acidity. This page has links to several pages that
will explain the basics of fertilization and plant nutrition. In addition, there is information on how to
make sure that your fertilizer injector is working well. Without an accurate fertilizer injector, it
may be very difficult to make sure that your plants get the nutrition they
need. In addition, there is software
that will help you make sure that your injector is providing the fertilizer
concentrations you need.
Click on the following links for more information (Some
of these links are PDF files, so you will need Acrobat Reader to open them):
EC and
pH: what are they and why do they matter?
All the basic information about pH and electrical conductivity a grower
needs to maintain good fertility levels in the growing medium.
Testing
the Waters Water qualilty can
greatly affect the growth of a crop and may affect how you should fertilize
your plants. Testing your irrigation
water on a regular basis will give you crucial information about how your water
may be affecting your crops.
Unfortunately, water quality terminology can be very confusing. Do you understand what pH, alkalinity,
hardness, carbonates, and salinity refer to?
For a primer on this terminology and related water issues, this summary
is a must.
Different
methods to measure the EC of your growing medium are described in this
reprint from GMPro.
Are
your plants on the right diet? Basic
information about greenhouse fertilization programs.
The
basics of fertilizer injector maintenance.
Everything you need to know to keep your injector working smoothly.
Nutrition
Guidelines for Bedding Plants.
Guidelines for fertilization of a variety of bedding plants in
subirrigation systems.
Excel spreadsheet for some basic fertilizer
calculations
This software was developed
to help with some of the most basic fertilizer calculations. It has the
following three functions:
·
Calculate the
amount of fertilizer to use when you are mixing stock solutions for use with a
fertilizer injector
·
Determine the
nitrogen concentration of a fertilizer solution, based on its electrical
conductivity
·
Calculate what
the electrical conductivity of your fertilizer solution should be, based on the
desired nitrogen concentration of the fertilizer
This software in the format
of an Excel spreadsheet and can be downloaded for your use. The file should be
opened as a 'read-only' file. This
assures that there will be no unwanted changes in the spreadsheet. Although I
have tried to make sure that all calculations in this spreadsheet are correct,
I cannot accept any liability for possible errors. So please use this software
at your own risk and if you find any errors, please contact me.
Click here to download fertilizer software
Microsoft Explorer
users: the file will open in
your browser window. To use the file, click on 'File', 'Save',
and save the file on your hard drive. You can then open it in Excel and use it.
It will not run correctly in your browser window.
Netscape users: you will be asked whether you want to save or open
the file. Save it on your hard drive and then open it in Excel to use it. It
will not run correctly in your browser window.
Back to
Marc van Iersel’s homepage
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the UGA Horticulture program:
Overview | Graduate Program | Undergrad Program | Extension | Commodities | Horticulture Club |
Links | Contact
the Department
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