<Li> reduction of water quality for users, sedimentation problems </Li> <Li> soil erosion ultimately, when crops are too strongly affected by the amounts of salts . </Li> <P> Salinity is an important land degradation problem . Soil salinity can be reduced by leaching soluble salts out of soil with excess irrigation water . Soil salinity control involves watertable control and flushing in combination with tile drainage or another form of subsurface drainage . A comprehensive treatment of soil salinity is available from the United Nations Food and Agriculture Organization . </P> <P> High levels of soil salinity can be tolerated if salt - tolerant plants are grown . Sensitive crops lose their vigor already in slightly saline soils, most crops are negatively affected by (moderately) saline soils, and only salinity resistant crops thrive in severely saline soils . The University of Wyoming and the Government of Alberta report data on the salt tolerance of plants . </P>

Describe how soil damage due to salinity could be reduced