What Does This Program Do?
GEOCHEM–EZ is a multi-purpose chemical speciation program, used in plant nutrition and in soil and environmental chemistry research to perform equilibrium speciation computations, allowing the user to estimate solution ion activities and to consider simple complexes and solid phases. Programs of this type allow the user to estimate the interactions between metals and ligands and to calculate the free activities of the ions of interest. In doing so, the scientist can make a solution in which requisite conditions are satisfied and the design is intelligent. See the full article on Geochem-EZ published in the journal Plant and Soil.[pdf]
For many years we have used speciation programs to formulate hydroponic solutions for plant growth, including those employing a variety of metal-chelate systems to control Fe (II), Fe (III), and Zn status. In addition, this program has been an important tool in creating test solutions for plant aluminum (Al) tolerance experiments. Thus, we are able to estimate Al3+ activities and to create solutions without significantly lowering available phosphate or sulfate.
To enhance the usability and to address several functional weaknesses in GEOCHEM-PC, we upgraded the program with a Java graphical interface, improving both the power and function, and allowing it to run on any computer which supports Windows XP, Vista, and Windows 7.
Note: The Geochem-EZ program requires Java SE6 update 7 or higher, which is available for download from Sun Microsystems (http://www.sun.com/download/index.jsp). If you are not sure whether you have the correct version or whether you have Java at all, then go to: http://www.java.com/en/download/help/testvm.xml?ff3 and it will test to see what is installed on your computer.
Geochem-EZ is available for download as a "zipped" file. Click on the link above "Click Here to Download Geochem-EZ" to access the zipped program file, to read about system requirements, and for installation instructions.
Click on this link for an example of the Geochem-EZ interface, displaying a basal Murashige-Skoog medium.
Why Should I Use This Program To Design My Experimental Solutions?
Many scientists have adapted standard nutrient solutions for their hydroponics or for their experimental treatments without having analyzed these solutions to see whether any precipitation or solids may form. Geochem-EZ can help predict this. Others may use this program to design sensible chelate buffer systems or to calculate the concentration of a particular ion needed to provide a constant activity. It is also a good way to know that there is sufficient free activity of important nutrients.
An example of the program's strength can be found in analyzing one of the solutions that is currently being used to investigate Al-tolerance in rice. Many rice lines are fairly Al tolerant and, thus, require higher concentrations of Al in their test solutions in order to elicit root growth inhibition. This higher Al concentration in the nutrient solution leads to ionic interactions that lower the activities of other solution components. As an example, we have analyzed a case with Geochem-EZ in which a researcher used a Yoshida’s rice nutrient solution (1), pH 4.0, with 1.1 mM (30 ppm) Al added. Geochem-EZ generates several different output files to help the user analyze the solution and to help them create an improved experimental solution. Click on this link to see the output files and the solution analysis for this Yoshida's solution with 30 ppm Al.
(1) Yoshida S, Forno D A, Cock J H and Gomez K 1972 In Laboratory Manual for Physiological Studies of Rice, 2nd Ed., The International Rice Research Institute, Los Baños, Philippines. pp 53–57. |
