Why were so many of the 282 laws about farming and irrigation?

They wanted things done a certain way.

Explanation:

When you imagine something in your head you think of it and when it actually happens you want it to be just like you imagined it. In order to have it just the way that you want it you have to have rules so that it would stay just as you wanted it. If something were messed up or done wrong while farming that could cause a time where they go with out and there could be hard time where some people go without food if even one little thing is done wrong.