Activities that increase the level of soil organic matter:

 leaving crop residues on the field, instead of burning or wasting them, as they are the major
source of biomass
applying compost: this is very effective, as part of the organic matter in compost is already
stabilised and will remain in the soil for a longer time than fresh plant material
applying organic manures: as they contain organic material, they help to increase the content
of organic matter; at the same time, they can speed up decomposition as they are rich in nitrogen
and thus stimulate soil organisms
mulching with plant materials or agro-wastes: especially applying hardy material (rich in fibres
or wood) will increase the organic matter content, as it will remain in the soil for a long time;
in addition, it helps to reduce erosion
using green manures or cover crops: green manures grown on the same field will contribute
biomass both from the leaves and roots; material grown on another site contributes only the
leaves; the younger the plant material is, the faster will it decompose, thus releasing the
nutrients faster but adding less to the built up of soil organic matter
Suitable crop rotation: including crops in the rotation which build up soil organic matter (e.g.
pastures); especially perennials and crops with a dense root system (e.g. pastures) are very
beneficial
reducing soil tillage: each tillage will speed up the decomposition of organic material, as it
aerates the soil and stimulates soil organisms
avoiding soil erosion: all methods listed before will be in vain unless soils are prevented from
erosion; it carries away those parts of the soil which contain most humus and are most fertile