Measuring Ion Concentrations in Plant Tissue - Agriculture - Horticulture

Measuring Ion Concentrations in Plant Tissue

Required Apparatus:

  • Aptisens Digital or Mobile Multiple Ion Kit
  • Weighing scales
  • Liquid measurement device e.g. graduated cylinder
  • Bowl for stirring
  • Spoon for stirring
  • Funnel
  • Filter paper / muslin
  • Conical flask / vessel

Required chemicals:

  • Aptisens multiple ion conditioning solution
  • Aptisens Plant Tissue multiple ion calibration solutions
  • Deionised water

Sample Preparation:
This preparation can be applied to any plant tissue. Take a sample of lettuce and remove any soil but do not wash the plant tissue as doing so may reduce the number of ions in sample. Weigh this sample and record (say 100 g). Macerate the plant tissue in a blender and add a known amount of hot deionised water to the sample to extract the nutrients. For example, dilute the sample two-fold (200 mL), three-fold (300 mL) or five-fold (500 mL). Ensure all the plant tissue is covered with water and leave to sit for approximately 30 min with some stirring. The sample then needs to be filtered.

Set up a funnel with folded filter paper in a conical flask or any vessel that can hold a funnel. Pour the plant tissue and water into the funnel and allow the mixture to filter. Collect the filtrate.

Before use the multiple ion probe must be conditioned in Aptisens multiple ion conditioning solution. Ensure the correct calibration solutions for a three-point calibration are set up on the Mobile meter or MeterLink. Follow the instructions for calibration and proceed to take a sample reading when the calibration data is ‘very good’ or ‘good’ for all ions.

Sample Reading:
Place the probe in the plant tissue filtrate and ‘Take a Sample’ reading. The concentrations for each ion will be displayed in ppm or mmol / L.

Remember to multiply these concentrations by the dilution factor.

Probe Care:
After taking your reading be sure to remove the sensors from the solution as quickly as possible, rinse with deionised water and replace the cap of the probe