How to conduct a simple scientific experiment in your garden
Nowadays, the abundance of available information can be both a blessing and a curse. In agriculture, like in many other scientific fields, coming across conflicting information is quite common. The good news is that you can check by yourself some of this information through basic scientific experiments. These experiments not only will improve your understanding of how science works but also assist in navigating the wealth of information accessible.
At the Mater lab, il Bosco Giardino, we recently acquired and propagated some plants of Symphytum officinalis, a.k.a. comfrey. Comfrey is known to have many properties and various agricultural uses. We’ve read tons of incredible claims about using comfrey as a fertilizer. So, we are interested in determine wether comfrey can really be used as an effective fertilizer. We will use this case-study as an example of how to set up a simple experiment to draw you own conclusion based on your observations and measured data.
Experiment setup
We will use tomato plants (Seccagno variety) as our “test subjects” and employ a Latin square design for the trial. The latin square is a very simple layout for a field experiment helps consider potential spatial variations in the existing soil fertility (see Figure 1). It is common for an agricultural soil to have varying fertility levels, with some areas supporting better plant growth than areas. This design will enable us to distinguish between differences due to soil characteristics and those resulting from our fertilization treatments.
Fertilization treatments
Our experiment will feature four treatments, each corresponding to a different fertilization strategy:
A: Tomato plants without fertilizer.
B: Tomato plants with compost applied onto the soil (no digging!).
C: Tomato plants treated with comfrey macerate used in fertigation.
D: Tomato plants treated with comfrey leaves as green mulch.
We will arrange our treatments using the Latin square layout, i.e. no treatment will be repeated on the same row and column (that’s basically Sudoku, right?). We will also strive to minimize the influence of any other variable by e.g., using the same irrigation volumes or planting them on the same day.
Data collection
At the end of the growing season, we will harvest and weight the tomatoes produced from each plot. We will then use these data to analyse them with a technique called ANalysis Of Variance (ANOVA) that will tell us if the comfrey fertilizer “works”.
For us, “works” will mean that a ferilization treatment had significantly increased the quantity (and possibly the quality? We will see…) of the tomatoes, in comparison to our control treatments (compost and untreated). By the end of our trial, we will have evaluated how effective comfrey is as a fertilizer for tomato crops and measured its impact on the fruit yield, using on empirical evidence.
What next?
This basic experiment demonstrate how you can easily use scientific methods to test the effectiveness of simple agricultural practices. We encourage you to try this experiment in your own garden to see firsthand the impact of different agricultural practices on your crops. Not only will this deepen your understanding of science, but it will also enable you to choose based on evidence of your own experimentation. Hands-on experimentation like this demystifies the scientific process and makes it accessible to everyone, helping us become better informed growers and consumers of scientific information.
This simple experiment demonstrates how you can easily use scientific methods to test the effectiveness of basic agricultural practices. We encourage to conduct an experiment like this in your garden to observe firsthand the impact of various practices on your crops. By doing so, you will deepen your understanding of how science works and will be able to make informed decisions based on your own experimental results.
Stay tuned for the next post, where we will show how to analyse the trial data.