﻿PLANT 
  INDUSTRIES 
  327 
  

  

  with 
  increased 
  rapidity. 
  In 
  so 
  doing 
  it 
  carries 
  away 
  large 
  

   quantities 
  of 
  soil, 
  sometimes 
  uncovering 
  the 
  burned 
  roots 
  

   until 
  the 
  trees 
  are 
  easily 
  overturned 
  by 
  winds. 
  1 
  

  

  There 
  are 
  several 
  means 
  of 
  preventing 
  much 
  of 
  this 
  loss 
  of 
  

   soil 
  by 
  erosion. 
  In 
  wooded 
  regions 
  judiciously 
  cutting 
  part 
  of 
  

   the 
  timber 
  each 
  year, 
  rather 
  than 
  cutting 
  all 
  of 
  it 
  at 
  once, 
  

   gives 
  opportunity 
  for 
  new 
  plants 
  to 
  occupy 
  and 
  hold 
  the 
  soil. 
  

   There 
  are 
  many 
  kinds 
  of 
  soil-holding 
  plants 
  which, 
  if 
  properly 
  

   placed, 
  will 
  prevent 
  erosion 
  in 
  its 
  earliest 
  stages, 
  and 
  these 
  

   should 
  be 
  used. 
  In 
  open, 
  hilly 
  fields 
  which 
  are 
  exposed 
  to 
  ero- 
  

   sion, 
  grass 
  and 
  meadow 
  crops 
  are 
  desirable, 
  since 
  their 
  roots 
  

   help 
  to 
  hold 
  the 
  soil 
  throughout 
  the 
  whole 
  year. 
  In 
  such 
  

   cases 
  the 
  roots 
  and 
  stems 
  help 
  to 
  prevent 
  the 
  rapid 
  run-off 
  

   of 
  the 
  surface 
  water. 
  The 
  very 
  things 
  that 
  need 
  to 
  be 
  done 
  

   in 
  the 
  cultivation 
  of 
  plants 
  increase 
  the 
  danger 
  of 
  loss 
  of 
  soil 
  

   where 
  rapid 
  flow 
  of 
  the 
  surface 
  water 
  cannot 
  be 
  prevented. 
  

  

  In 
  hilly 
  fields 
  it 
  is 
  often 
  difficult, 
  sometimes 
  impossible, 
  to 
  

   prevent 
  erosion. 
  In 
  some 
  localities 
  the 
  rows 
  of 
  growing 
  plants 
  

   are 
  arranged 
  across 
  the 
  slope 
  of 
  the 
  hill 
  ; 
  this 
  arrangement 
  

   helps 
  somewhat 
  in 
  retarding 
  the 
  surface 
  flow 
  of 
  water. 
  If 
  culti- 
  

   vation 
  is 
  continued 
  in 
  such 
  places, 
  the 
  soil 
  sooner 
  or 
  later 
  be- 
  

   comes 
  eroded, 
  and 
  it 
  is 
  with 
  extreme 
  difficulty 
  that 
  any 
  plants 
  

   gain 
  a 
  foothold 
  (fig. 
  240). 
  In 
  some 
  foreign 
  countries 
  hillsides 
  

   have 
  been 
  saved 
  for 
  cultivation 
  by 
  a 
  process 
  of 
  terracing. 
  

   The 
  terraces 
  are 
  constructed 
  in 
  such 
  a 
  way 
  that 
  the 
  soil 
  upon 
  

   each 
  is 
  level 
  or 
  slopes 
  toward 
  the 
  hill, 
  thus 
  retarding 
  or 
  pre- 
  

   venting 
  erosion. 
  Such 
  terraced 
  farms 
  are 
  sometimes 
  most 
  desir- 
  

   able 
  for 
  vineyards, 
  but 
  it 
  is 
  obvious 
  that 
  for 
  ordinary 
  crops 
  these 
  

   elaborate 
  processes 
  of 
  terracing, 
  and 
  the 
  constant 
  care 
  required, 
  

   will 
  prove 
  profitable 
  only 
  where 
  available 
  land 
  is 
  extremely 
  

   scarce. 
  In 
  many 
  localities 
  where 
  the 
  slope 
  of 
  the 
  surface 
  is 
  

   moderate 
  enough, 
  underground 
  drains 
  may 
  be 
  laid 
  to 
  take 
  care 
  

   of 
  the 
  surface 
  flow 
  and 
  thus 
  prevent 
  erosion 
  except 
  at 
  times 
  of 
  

   extremely 
  heavy 
  rains. 
  

  

  1 
  "The 
  Movement 
  of 
  Soil 
  Material 
  by 
  the 
  Wind," 
  Bulletin 
  68, 
  Bureau 
  of 
  

   Soils, 
  U.S. 
  Dept. 
  Agr., 
  1911. 
  

  

  