The set up of suspense is dramatic. I could practically feel the cold and hear the farmers shouting (read as as shooting at first.) The climax in this sentence could be improved by stating clearly how the air was let out of the tyres. I am not sure the term "popping" works :
The shouting multiplied as the farmers surrounded the bus and you could hear the air slowly leaving the tires as they popped them one by one.
After this ordeal I realized the struggles that some of these farmers go through. Toiling long hours over their crops and only making enough for a meager living.
Join the first sentence with the second phrase with a comma.
It made me realize that I should not be going to college just to graduate and make plenty of money, but instead to learn skills that will allow me to give back to my community and people in need. WHAT SKILLS DO YOU THINK WILL BE THE MOST VALUABLE TO YOUR COMMUNITY?? Although the event lingers on in my mind, it acts as a reminder to use the privilege of attending a university not to earn a comfortable living but instead to be a service to people like the farmers in Peru.
HOW CAN YOUR EDUCATION BE A SERVICE TO YOUR COUNTRY'S FARMERS? DOES THIS MEAN STUDYING AGRO-BUSINESS or SOCIAL DEVELOPMENT or being a journalist, a human rights activist?