March  i,  1893.]  THE  TROPICAL  AGRICULTURIST.  603 
cultivation  of  the  many  fields  constituting  a large 
estate  would  mean  loss  and  disappointment  as  well 
as  gain.  I do  not  think  it  would  be  safe  to  go 
beyond  the  experience  that  has  already  been  pretty 
generally  acquired  : that  cattle  manure,  bones, 
poonac  and  castor-cake,  judioiously  applied  are  safe 
and  sure,  pretty  nearly  everywhere,  leaving  alone 
soils  of  great  depth  giving  yearly  good  average 
returns,  Shallow  buryings  of  weeds  and  prunings 
are  good  on  easy  lays  of  land.  They  always  get 
well  rotted  and  decomposed  where  the  conditions 
allow  the  rain  to  sink  in — air  follows  the  moisture 
infallibly,  for  as  the  moisture  sinks  it 
leaves  a vacuum  which  tbe  pressure  of  the 
atmosphere  as  quickly  fills  up  with  air.  Burying 
immense  quantities  of  prunings  together  in  one 
large,  deep  hole  can  only  be  for  the  purpose  of 
getting  rid  of  them,  to  the  prejudice  of  a few  neigh- 
bouring plants,  unless  soil  is  plentifully  added  and 
well  mixed.  Scientific  cultivation  of  a large  estate 
requires  the  purse  of  a Worms  on  a Rothschild 
estate. — Yours  truly,  OLD  PLANTER. 
[The  above  was  partly  written  with  reference  to  an 
extraot  from  Ooorg  Notes  in  the  Madras  Mail , 
of  whioh  we  give  the  gist: — 
PLANTING  NOTES  FROM  COORG. 
(FBOM  OUB  OWN  CORBESPONDENT.) 
Coorg,  Jan.  23. — I thought  it  necessary  in  the  in- 
terests of  planting  to  oall  attention  to  the  errors 
whioh  “ Planter  ” wes  led  into  in  writing  on  the 
subject  of  the  Weeding  of  Coffee  Estates  in  the  Madras 
Mail  of  tbe  10th  of  Septembsr  last.  “Planter’s” 
observations  were  obviously  the  first-fru  ts  of  a perusal 
of  Mr.  Graham  Anderson’s  letter  on  the  same  subject ; 
but,  as  I said  in  some  previous  Notes,  none  of  them 
were  warranted  by  anything  the  latter  had  written. 
The  following  statements  occur  in  tbe  opening  lines 
ot  “Planter’s”  letter: — “ The  buryiDg  of  weeds  is 
a mistake,  favouring  as  it  does  fermentation  rather 
than  decay.  Fermentation,  unlike  decay,  is  not  a 
process  of  oxidation.’’  It  will  be  sufficient  to  quote 
what  Dr.  Fream  has  to  say  of  fermentation  in  his  “ Ele- 
ments of  Agriculture.”  to  convince  him  that  thtse 
statements  are  erroneous.  We  learn  that  “ fermen- 
tation is  tbe  Dame  given  to  those  chemical  changes  which 
result  in  making  the  manure  ‘ ripe  ’ or  ‘ mellow’ and 
better  adapted  to  the  immediate  U6e  of  growing  plants, 
it  is  a process  of  oxidation,  and  can  only  take  place 
where  there  is  free  aocess  of  air.  Heat  is  produced  by 
the  union  of  oxygen  with  the  ingedients  of  the  dung, 
and  the  more  rapid  the  fermentation  the  greater  is  the 
heat.  It  is  obvious  then  that  fermentation  may  be 
controlled  by  increasing  or  diminishing  the  quantity 
of  air  that  gains  aocess  to  the  heap,  the  oxidation  being 
most  aotive  when  the  manure  lies  loosely,  and  least 
so  when  the  heap  is  oompressed.”  We  see,  then,  that 
the  burying  of  weeds  would  have  the  effect  of 
ohecking  fermentation  to  the  extent  to  which  it 
prevented  access  of  air  to  them  ; and  that 
fermentation  resembles  decay  in  being  a prooess 
of  oxidation.  In  fact,  I think  they  may  safely 
be  taken  as  synonymous  terms. 
But  first  let  us  see  what  may  be  learnt  as  regards 
the  changes  which  take  plaoe  in  the  formation  of 
silage  that  may  aid  in  elucidating  the  matters  here 
dealt  with.  In  Froam  we  read  tbat  tbe  object  in 
silage  is  to  imitate  and  improve  upon  the  tightly 
pressed  dung  heap,  and,  by  exoludmg  the  air,  to 
prevent  oxidation.  Whether  “sweet”  or  sour  ” 
silage  results  from  the  operation  is  mainly  dependent 
on  the  temperature  at  which  fermentation  tabes 
place  within  the  mass  of  herbage.  When  the  pre- 
cautions that  have  to  be  adopted  to  ineur6  suc- 
cess in  osilage  are  considered,  it  is  difficult  to  con- 
ceive how  air  could  he  so  thoroughly  excluded  in 
“burying  in”  as  is  claimed  to  have  been  the  case 
It  all  depcnis  on  tbe  depth  of  the  earth  covering  pnt 
over  the  weeds.  The  operation  as  practised  in  Ooorg 
was  as  it  is  described  by  Hull,  i.e.,  a shallow 
)»9l9  9K  tieiwh  was  dug  and  all  the  weeds  for 
several  feet  round  were  scraped  on  to  it  and 
covered  over.  Hull  speaks  very  highly  of  it  as 
being  an  effectusl  plan  in  getting  rid  of  weeds  where 
they  nre  high  and  rank,  and  yet  in  another  place  he 
says  tbat  weeds  shonld  not  be  turned  in  too  deeply, 
as  fermentation  to  separate  the  woody  fibre  is 
thereby  prevented,  so  that  he  did  not  consider  that 
“burying  in”  did  harm  in  the  same  way.  Sabona- 
diere  says  that  closed  trenching  in  Oeylon  was 
attended  with  marked  benefit,  especially  in  stiff  soils. 
This  consisted  of  cutting  a ditch  across  the  entire 
length  of  the  rows  of  ooffee  and  filling  them  in  with 
mana  grass,  the  vegetable  matter  of  swamps,  &o.,  and 
covering  them  over  with  soil.  Munro  says  that  the 
decay  of  vegetable  matter  serves  to  keep  soils  open 
or  porous  by  continually  producing  gas.  We  thus 
see  how  the  supply  of  air  would  be  kept  up  in 
“ burying  in.”  The  air  buried  in  with  the  weeds 
would  start  fermentation  as  it  does  in  silage,  and 
the  gas  thus  generated  would  burst  air  passages 
through  the  covering  of  mould,  provided  it  was  not 
too  dense. 
Mr.  Anderson’s  saymg  that  “ the  proximity  of 
semi -decomposed  vegetable  matter  must  be  as  hurtful 
to  the  living  plants  as  a festering  corpse  is  to  a 
human  being  ” is,  to  say  the  least,  unhappy,  for  we 
are  told  (Elements  of  Tropical  Agriculture)  that  the 
effect  of  alkaline  substances  in  the  soil  is  to  couuteraot 
the  evils  arising  from  the  accumulation  of  acid  substan- 
ces and  other  “pernioious  combinations.”  If  there  be 
an  insnffioiency  of  these  alkaline  substances,  the  fur. 
ther  natural  decay  of  organio  matter  would  be  ar. 
rested  and  the  soil  would  become  sour,  if  there  are 
any  indications  of  this,  however,  matters)  are  best 
remedied  by  the  additioo  of  lime,  the  duty  of  which 
is  to  keep  soil  permanently  lasio.  In  one  estate  here, 
lime  has  been  mixed  with  cattle  manure.  This  pro- 
ceeding is  countenanced  by  scientists  and  is  bound  to 
be  beneficial ; but  planters  generally  still  fight  shy  of 
it.  It  is  not  only  in  “burying  in”  that  “pernicious 
combinations’’  are  formed,  as  we  read  in  the  same 
book  that  they  resuit  when  organic  matter  undergoes 
decay  in  the  presence  of  air  and  water,  so  that  they 
are  formed  in  well  worked  soils  as  well.  The  great 
argument  in  favour  of  “buryiDg  in”  was  that  the  vola- 
tile products  of  the  first  stages  of  the  decay  of  the 
weeds,  instead  of  being  dissipated  in  the  air,  was 
caught  by  the  covering  of  mould  and  made  to  take 
new  forms  which  are  most  valuable  food  for  plants; 
and  the  surfaoe  was  not  robbed  of  organio  matter 
as  the  humus  partioles  were  returned  to  the  surfaoe 
when  the  pits  were  reopened  and  in  renovation 
pitting,  &c.  In  another  plaoe  Mr.  Anderson  speaks 
of  a sample  of  vegetable  matter  completely  bound 
together  with  fungoid  filaments  whioh,  after  the  dig. 
ging,  was  altered  in  appearance  and  the  fungus 
disappeared,  and  he  asks  “ Does  this  prove  tbat  the 
food  for  the  fungus  has  passed  into  a more  advanced 
stage  and  has  become  food  for  a hire  order  of  plant?” 
We  will  presently  come  to  the  work  of  fungi,  but  first 
let  me  say  that  this  would  seem  to  imply  that  after 
vegetable  matter  has  crumbled  into  the  humus  stage 
it  beoomes  a direct  plant  food.  All  agriculturists  say 
this  is  not  the  case,  but  that  the  final  products  of 
its  decomposition— chiefly  carbonic  acid,  ammonia  and 
water — are  capable  of  administering  to  the  food  re- 
quirements of  plants.  “ Planter  ” further  said  “ Fer- 
mentation is  always  accompanied  by  the  development 
of  living  organisms  of  the  fungus  class.”  We  have  an 
instance  in  sweet  silage  of  high  temperature  fermen- 
tation hilling  living  organisms.  These  living  orgaDiema 
tbe  most  tamiliar  of  whioh  is  tha  yeast  plant,  are 
productive  ol  the  greatest  possible  good  to  plants  as 
they  are  instrumental,  as  Munro  tells  us,  in  bringing 
about  nitrification,  which  is  the  name  given  to  the 
production  and  accumulation  of  nitrate  of  lime,  a 
most  valuable  plant  food,  in  the  soil.  Soil  exposed 
to  much  heat  (over  140°F)  results  in  the  stoppage 
cf  the  production  of  nitrate  of  lime,  as  this  heat,  as 
has  been  seen  in  silage,  kills  the  living  ferments.  It 
is  obviously  undesirable  therefore  that  weeds  should 
be  so  exposed  as  to  cause  a high  temperature  for. 
mentation) 
