We maintain fertility through regular cover cropping. A cover crop is a crop that is planted for reasons other than harvesting. As the name suggests, it covers the soil while there is no cash crop. This prevents soil loss from wind and/or rain erosion. It also suppresses weeds that may otherwise be growing there.
When we mow a cover crop, we let it break down right there. This is an easy way of incorporating compost into the soil, sometimes referred to as “green manure”.