On the other hand, many farmers who use
compost made from livestock manure are becoming
old, and are often part-time farmers. They are
tending to use less compost because they lack the
time and strength to apply it. Thus, even livestock
farms in regions where the nitrogen content of the
soil is low cannot find enough cropland on which to
apply their compost. In these regions, groundwater
has become polluted by nitrate because of heavy
applications of composted livestock manure onto a
limited area of cropland. Therefore, with these
problems in mind, it is necessary to create an
environmentally safe recycling system for
composted livestock manure.