The quote simply means that if one invests for a year, the person will get rice; if the person invests for ten years, he or she will get trees and for hundred years, the investment will yield people when contribute positively to the growth of the society.
The quote means that education takes time. It's not an investment that yield instant result like that of rice in a year. An example is when one has to go through nursery, primary, secondary or high school and later go to higher institution for their B.Sc programe. Even some go further for their Masters and PhD programmes. This shows that investing in education takes a longer period but it's definitely worth it.
