Biodiverse means having more than one type of crop on your farm, rotating the crops, and planting complementary crops together (also called intercropping). These practices all have various benefits such as better pest resistance and reversing nitrogen depletion. However, most importantly, it insures against crop failure. If the corn fails, then you can still sell or eat potatoes, for example.
SERVING THE COMMUNITY
Serving the community means that farms provide a valuable resource and support the local economy. It is estimated that about 2 billion of the world's population work on small farms! Organic farming methods are a lot more labour intensive because most of the machines that are used on big, industrial farms were designed for monoculture. For example, harvesters can't deal with multiple crops, so a lot more workers need to be hired to get the job done by hand. This creates many of the jobs that small farming communities depend on.
Self-sustaining means that you're minimizing the use of "inputs" such as water, fertilizer, and pesticides. Organic farming practices such as these results in the creation of new topsoil which is very important for the long-term health and production of the farm. Healthy soil is much richer in beneficial microorganisms which create a kind of fungal internet that channels nutrients and water, making it more productive and drought resistant.