Any of various substances that show the presence, absence, or concentration of a substance.

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion

the "power" of a lens is its resolution power, or its ability to distinguish between to closely located points. with the low power lens, it is likely you will see the rough form of the hay and maybe some movement of dots around the hay. however, when observed with the high power lens, the detailed features of the hay become visible and the microbes being grown are more clearly visible.

i hope this you

. the sierra madre fault zone of southern california

. the san andreas fault california