Hi
I want to use CaCO3 in 1/2 Hoagland nutrient solution until simulate conditions usually found in the field lead to iron deficiency. I followed some articles material and methods. 0.5gl-1 CaCO3 +20mM NaHCO3 but unfortunately I saw precipitation.
Would you please tell me how can I solve CaCO3 plus NaHCO3 in 1/2 Hoagland nutrient solution without any problem?
Thanks
The pH of water determines the solubility and biological availability of nutrients, specifically metals such as iron. The most common species of ferric iron in natural waters is ferric hydroxide, Fe(OH)3 (or more correctly, Fe203 -3H20). Addition of calcium carbonate or bicarbonate increases the pH of the solution above 6.5 to as high as 8.5. In the pH range of 5 to 8 as the solubility of naturally low soluble CaCO3 itself depends on temperature and pH, Fe(OH)3 is largely in the solid state and thus the solubility is very low. So, the pH of the nutrient solution should be an important factor deciding the bioavailability of iron and simulating Fe-deficiency condition in the field. The following links may provide useful links to literature pertaining to the query:
http://www.watercheck.com/pdf/TechnicalArticles/TechnicalArticles2/RelationshipbetweenpHandIron.pdf
http://pubs.usgs.gov/wsp/1459a/report.pdf
http://gwri-ic.technion.ac.il/pdf/gwri_abstracts/2007/2007-40.pdf