MONITORING CHEMICAL-PROPERTIES OF CONTAINER GROWING MEDIA WITH SMALL SOIL SOLUTION SAMPLERS

Soil solution samples from peat-based growing media, irrigated with di fferent nutrient solutions, were extracted at container capacity with small hydrophilic polymer soil moisture samplers (SMS), analyzed for p H, electrical conductivity (EC), NO3-N and NH4-N, and evaluated agains t results obtained by saturated media extract (SME) and pour-through ( PT) procedures. The correlation between applied and extractable NO3-N, NH4-N and EC was excellent (r(2) >0.98) far all methods. Values from SMS were statistically similar to those from PT, whereas those obtaine d by SME were significantly lower. In contrast to the above mentioned chemical parameters, pH readings among extraction procedures were less correlated and more variable, particularly in a peat:perlite medium. Simplicity of use, non-ion exchange properties, low cost and good pote ntial longevity make SMS promising monitoring tools for container crop production and mineral nutrition research. (C) 1998 Elsevier Science B.V.