Something that affects us all, but few people, especially westerners, know little about, would be farming.  We all depend upon food to live and yet such inattention is paid that before lonf, if we are not careful, we could find ourselves a problem in the food supply.  One obvious example of this would be the recent surge of erosion, bad weather, and natural disasters resulting from poor farming techniques and obvious poor planning. 

Erosion, not always a problem, has become recently worse, due to overindustrialization and poor management of resources.  Though poor countries have the worst problem because of their substandard levels of education, there is no lack of difficulty in keeping erosion at bay in the more developed areas as well. 

One way farmers deal with this natural thief, is to intercrop, polyvariential farm, and agroforestry, and polyculture.  All these techniques use mutiple plants to hold the soil together, catch any and all water before it leaches away, protects weaker plants from elemental fury, and renew the soil through depositing different minerals and vitamins. 

This picture is an example of the more complicated style farmers use to keep land fertile and leach-bound.  This polyvariential farming puts various plants together to live mutually; feeding off each other's strenths, but not sapping the weakness.  This conserves land, water, and provides the farmer with a backup plan...in cased one of the crops "give up" and die due to above said factors.  

Intercropping is similar, but more simple.  Farmers simply place two species of plants together and hope that one protects the other. The below picture is an example of intercropping.

Agroforestry is like the above idea, but there is one slight exception.  Trees are planted beside crops to protect against forceful winds and other violent nature forces.  They also will shelter the plants from excessive sun and provide nutrients.  This is yet one more way farmers across the world are revitalizing thier croplands.