ISHS Acta Horticulturae 294: II Symposium on Horticultural Substrates and their Analysis, XXIII IHC
ASSESSMENT OF AVAILABLE NUTRIENTS IN POTTING MEDIA USING DILUTE DTPA EXTRACTANTS |
| Author: | K.A. HANDRECK |
| Abstract:
Data are presented on the effectiveness of dilute, unbuffered aqueous solutions of DTPA for assessing the availability of nutrient elements in potting media. Saturated media extracts containing DTPA (SMED) and 1:1.5 volume extracts with 2 mM DTPA are shown to extract Fe, Cu, B, P, S and N in concentrations which are highly correlated with uptake by, and growth of, a wide range of plants. Limited data for Mn and Zn also indicate good correlation. Interpretation of data for K, Ca and Mg should be cautious until more information is available. The electrical conductivities of DTPA extracts are slightly higher than those of equivalent aqueous extracts but are highly correlated with them. Correlation between pH values is good, but is influenced by buffer capacity. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
