378 
On  the  Power  of  Soils  to  absorb  Manure. 
soil,  by  which  continual  exposure  to  atmospheric  influences  its 
absorbent  power  is  greatly  augmented. 
In  the  use  of  liquid  manure  we  may  derive  some  important 
lessons  from  the  study  of  the  absorptive  power  of  soils.  It  has 
been  usual  to  apply  manure  in  the  liquid  form  wholly  or  prin- 
cipally to  grass  land,  or  to  the  artificial  grasses,  clover  and  Italian 
rye-grass.  Without  doubt  there  are  practical  difficulties  in  the 
use  of  this  kind  of  manure  to  arable  lands,  but  we  may  fairly 
assume  that  to  some  extent  the  limitation  of  its  use  is  to  be 
ascribed  to  the  general  impression  that  liquid  manure  must  be 
applied  to  the  plants.  But  we  now  find  that  by  virtue  of  its 
absorptive  power  for  the  ingredients  of  manure  we  may  leave  to  the 
soil  the  care  of  preserving  these  substances  until  they  are  wanted 
for  a following  crop.  If  we  closely  analyze  our  ideas  of  ma- 
nuring, we  shall  find  that  they  proceed  upon  the  conviction  that 
the  earth  is  a great  strainer , but  not  a chemical  filter ; and  to 
throw  liquid  manure  in  large  quantity  on  land  not  bearing  a crop 
would  be  thought  only  a laborious  means  of  getting  rid  of  it  by 
the  drains.  It  follows,  however,  from  the  facts  now  developed, 
that  if  the  practical  difficulties  are  overcome,  manure  in  the  liquid 
form  may  be  applied  to  a fallow  without  fear  of  loss. 
This  view  may  materially  facilitate  the  employment  of  the 
liquid  sewage  of  towns  by  rendering  the  application  more  constant, 
and  thereby  equalizing  the  demand  for  the  manure. 
The  theory  and  practice  of  Irrigation  will  probably  gain  much 
assistance  from  a proper  consideration  of  the  absorptive  powers 
of  soils.  The  beneficial  action  of  water  on  meadows  has  been 
the  subject  of  much  discussion:  on  the  one  hand*  it  has  been 
attributed  to  the  warmth  of  the  water  and  the  protection  it  af- 
fords to  the  herbage  in  the  winter  season ; on  the  other,  to  the 
salts  and  organic  matters  thus  supplied  to  the  plants.  The  truth, 
as  in  most  cases,  may  perhaps  lie  between  these  views,  but  so  far 
as  the  beneficial  effects  of  the  water  in  a chemical  sense  are  con- 
* There  can  be  no  doubt  that  the  effect  of  irrigation  in  winter 
is  a complex  one,  due  to  no  single  principle,  but  combining  several. 
Warmth  is  one  principle ; the  deposit  of  sedimentary  matter  is 
another.  The  filtration  of  soluble  salts  mag  be  a third  ; but  it  must 
not  be  forgotten  that  by  far  the  greater  part  of  the  water  flows  over, 
not  through  the  land.  Consequently  we  should  take  care  that  the 
runnings  of  yards  should  be  allowed  just  to  cover  the  land,  and 
that  the  flow  should  then  be  stopped,  in  order  that  they  may  sink 
into  it.  It  is  remarkable  that  Lord  Hatherton’s  meadows  .are 
irrigated  entirely  from  drains,  the  water  of  which  has  therefore 
already  undergone  this  very  process  of  filtration  before  it  fertilises 
the  land. — Ph.  Pusey. 
