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Trials: Data collection and assessment

April 5, 2021

In our previous article about growing media trials you’ve read about the importance of an adequate preparation of the trial. Once you’ve got everything set up and have a clear plan you should start focusing on your data collection methods.

Previous article: How to conduct a trial in 5 steps
In this article we share some handy tips for data collection during growing media trials to help you make an informed decision.

Make an assessment list

At the start of the trial, or prior to it, you should create an assessment list to make sure your data collection will be consistent. Write down the things that you want to monitor. Remember that recording more than you will eventually need is easier and more reliable than having to think back about something you haven’t written down. Here are some focus areas that might prove relevant, depending on your goals:

  • Irrigation frequency
  • Irrigation volume
  • Fertilizing schedule/timing
  • Fertilizing volume
  • Fertilizer composition
  • pH
  • EC
  • Water uptake and drainage
  • Root development
  • Plant growth (foliage)
  • Plant health

Depending on the goal of your trial you may not want to treat the growing media you are comparing in the same way. If you are looking for a mixture that helps you save water, that’s what you need to trial for. Make sure to carefully document everything you do, to be able to compare the results.

Documentation: Evaluation scales

It can also be very helpful to come up with an evaluation scale to rate different properties and changes. This way you can easily assign a score to mark which group of plants do best.


Growing media trial scale


You can either score the groups individually or you can use the scale to compare development. For that second option a score of 1 could mean the growing media you are trialing scores significantly worse compared to your regular mix. A score of 3 could mean they both do equally well, while 5 indicates the plants in the new mixture do significantly better.

Documentation: Pictures

Taking pictures of situations that stand out is a great way to create a reliable documentation. However, don’t just take pictures, but make sure to label and rate them as well, as trying to do this afterwards can cause challenges and confusion.

Pick a set day

To get the most out of the growing media trial you should collect data with regular intervals. This allows you to monitor the changes in plant growth and development closely. Picking a set day of the week and scheduling ahead helps you avoid losing track of the trial when other things come up.

Keep all of these things in mind and consider them carefully before you start your trial. Keep an eye out for our final article in these series. We will focus on the evaluation phase of the trial and help you draw clear and unbiased decisions.

Talk to our Sales Advisors if you’d like to get more handy tips for your data collection.