11/18/2009 - By Harrell's

Keeping tabs on your PH and EC is critical for a successful Nursery crop. In this article from NC State University College of Agriculture & Life Sciences Department of Horticultural Science, Ted E. Bilderback (Nursery Extension Specialist) reviews the procedure.

Introduction: Every nursery needs to have someone who routinely checks Electrical Conductivity (EC) also called soluble salts, and pH of container crops, potting inventories and irrigation water. Checking EC and pH should be considered part of the quality control and scouting program in the nursery. Results from testing 3 to 5 containers in a irrigation zone each week can be used to schedule irrigation the following week. Comparing leachate solution collected from containers to water collected from irrigation nozzles provides a good insight into nutrient levels in the containers. Checking EC and pH of nursery crops grown in containers doesn’t have to be time consuming, complicated or difficult. The intention of this article is to review the procedure and update growers on the Virginia Tech Extraction Method (VTEM), also called the PourThru extraction procedure.

Equipment: A variety of equipment can be used to monitor pH and EC. Equipment usually can be purchased as a pen or a meter . Many horticulture or nursery supply companies carry pH and EC testing equipment and standards. Most pens and meters are temperature compensating, however read the information that comes with the equipment to determine if any adjustments are necessary related to environmental conditions. If you purchase a pH meter or pen, you should also order a pint of pH 4 or 7 buffer (standardizing) solution. A standard solution should also be purchased when you purchase EC pens and meters to assure your equipment is calibrated and working properly.

Some units such at the Myron-L AG-6 can be bought as an all in one unit, including both pH and conductivity. All in one units have a built in cup to hold the leachate solution which makes them very suitable for use in the nursery when using a truck tail gate or wagon bed in the same manner as a lab bench. An EC / pH combination unit such as the Myron AG-6 costs around $400. A Hanna combo portable meter which uses a cable to connect the EC and pH electrodes to the meter sells for less than $175. Read the complete article