Additionally, look at the list of all the available nutrients and guess which ones the trees might need. Define an experiment to verify your hypothesis and use the population model to run it. If you are unable to prove or disprove your hypothesis, and you are sure that you have read the instructions , you may have to re-define your experiment and try again. The experiment should have given you the answers to the problem. A final comment regarding the nutrients is that people tend to call the nutrients plant food when in reality it has nothing to do with food.
Food is something that an organism needs to process to extract minerals, proteins, etc.
In the case of trees, the nutrients that are dissolved in the water are ready to get into the system to be used in the vital processes to spur growth and health. You should also be aware that not all trees need the same variety or amounts of nutrients. I hope that you had a successful first experiment. Let's now move to the second one. Since we will use the same format in all experiments, the descriptions will become less wordy.