Gleaning is the practice of gathering the leftover crops after a farmer has reaped the harvest. It is an ancient practice that has provided food and livelihood for the poor for thousands of years.   In the Biblical Book of Leviticus, farmers are instructed to not reap (collect crops) all the way to the edges of their fields.  Instead God commands the farmers to leave some of their crops behind for the poor to come and gather.

Gleaning has served as a form of social welfare throughout the ages.  In nineteenth century England there were laws about who was allowed to glean (orphans, widows, the poor). Church bells would ring to announce that the farmers were done reaping and the gleaning could begin.
Gleaning is a form of sustainable farming because it makes the most of the land.  When a reaping only yields 90% of a harvest, the gleanings yields the remaining 10%.  Thus nothing is wasted. 

Organic Farming:

Most farming today is done with pesticides.  Pesticides are used to kill bugs that eat the crops.  But pesticides are also harmful to the people who eat the crops as well as all the plants and animals that live in the area where they are used.  Farming without pesticides is called organic farming.  In order to not use pesticides, farms need to use other techniques to get a good yield from their farms. 

The Story of Ruth:

In the Bible there is a story of a woman named Ruth.  She was very poor.  But instead of just taking care of herself, she spent her days gleaning in order to feed all of her relatives.  She gleaned the land belonging to a very rich man named Boaz.  Boaz noticed how hardworking and altruistic she was.  He asked Ruth to marry him.  Ruth agreed and married Boaz.  She became rich and was able to take care of herself and all her relatives with ease.