ACID RAIN HOW DOES ACID RAIN AFFECT SEEDS AND PLANTS?

Once upon a time ONCE UPON A TIME... … 8C got a task: They were to investigate how acid rain affects cutlings and seeds. The students worked and worked…

Experiment setup … and finally the setup of the experiment was ready: Three different ”rain waters” were made: 1. plain, neutral water 2. acid rain at pH 5 3. really acid rain at pH 4 Cutlings of a garden plant, ”Painted nettle” (Solenostemon scutellarioides), were put in the three different ”rain waters” and left for a week. There were three groups of students doing the same experiments.

A week later all the nettles in neutral water were alive and well.

At pH 5 the results were not that good – one nettle did quite well, one wasn’t that ok anymore and one had almost given up. Was there perhaps a slight pH difference between the three separate experiments at pH 5?

And what had happened in the pH 4 ”acid rain” jars? Well… not much left of those nettles, is there?

Alfalfa seeds were sown on soil and watered with the same three ”rain waters” as earlier, namely not treated water as well as ”acid rain” at pH 5 and at pH 4. After a week the results were checked. Then we had the seed experiments.

Clean water – wonderful for growing alfalfa sprouts! (The cup with less sprouts in the picture just had less seeds in it from the beginning.)

pH 5 still works fine, alfalfa is apparently not very sensitive to pH.

BUT… don’t use very acidic rain water if you want sprouts, pH 4 will not give you much of a harvest! Conclusions: Acid rain does harm seeds as well as plants by either restricting the growth or killing the plant. Some species are more sensitive to low pH than others.