GEOG M107 Lecture Notes - Lecture 1: Natural Resources Conservation Service, Tillage, Nonpoint Source Pollution
Document Summary
Vital resources for food, fibers, other necessities. Resources decline gradually, lacking attention until something drastic happens (like the dust bowl) Dramatic events less loss than small losses accruing over years. Degradation worse in developing areas where survival needs supersede long- term planning & conservation. Increasing strain on soils, water resources, ecosystems. Other means of growing food & fiber more expensive in time and money. Formation too slow to keep up with erosion. In past, more crops grown by using more land. Currently, increased production obtained by more intensive land use rather than more land. Reduced erosion: new crop varieties (alternate between crops that can grow in different seasons), increased fertilizers, increased plant cover (plant cover can hold soil in place, won"t erode with rain) Increased erosion: more row crops, multiple cropping. As of 1999, world average 0. 1 ha/person needed. Important to maintain productivity while also using soil. Topography: gradient, shape, length, slope aspect control erosion & practicality.
