1.1 Background of the study
Soil is a vital resource for the future of humanity, it needs to be protected and
enhanced (Young et. al.,2015).More than half (52%) of all fertile, food producing
soils globally are now classified as degraded, many of them severely degraded
(UNCCD, 2015). Soils are our major natural resources because most of our food
and clothing comes directly or indirectly from them.
Soil degradation is a critical and growing global problem, with implications for a
number of key policy areas including food security, climate change, food risk
management, drought tolerance, drinking water quality, agricultural resilience in
the face of new crop diseases and biodiversity (Young et. al., 2015). Soil
degradation is one of the most important threats facing mankind which not only
weakens productive capability of an ecosystem but also affects overall climate
(Barrow, 1991). Soil degradation is the decline in soil characteristics originated by
its inappropriate use typically for agricultural, pastural, industrial or urban causes
(Johnson and Lewis 1995). Degradation in soil is the decline in any or all of the
characteristics which make soil suitable for food production.
This comes about due to activities such as improper land use, agriculture and pasture, urban or industrial
purpose. Examples of soil degradation includes adverse changes in alkalinity,
decline in soil fertility, adverse changes in acidity or salinity and extreme flooding.
Many interrelated factors, both natural and managerial causes soil fertility decline.
This decline may occur through leaching, soil erosion and crop harvesting.