Mav  I,  1897.]  THE  TROPICAL  AGRICULTURIST. 
777 
THE  MANURING  OF  TEA  ESTATES. 
We  h.ave  much  pleasure  in  laying  before  our 
readers  the  following  valuable  review  by 
Mr.  John  Hughes  of  the  series  of  letters 
on  Manuring  of  Tea  which  recently  appeared  in 
cur  columns.  Mr.  Hughes  coui])lains  in  a private 
note  tliat  many  of  the  replies  we  received  to 
our  questions  are  rather  vague  and  general,  no 
details  being  given  of  actual  results  and  cost  as 
compared  with  increased  yield.  Such  figures  are 
absolutely  necessary  to  the  formation  of  a prac- 
tical opinion  for  future  guidance.  However,  Mr. 
Hughes  enters  very  carefully  into  the  whole  ques- 
tion and  his  facts  and  figures,  as  well  as  practical 
counsel,  cannot  fail  to  be  of  much  service  to 
all  careful  and  thoughtful  tea  planters  in  Ceylon 
and  elsewhere.  The  Report  is  as  follows: — 
By  the  last  mail  the  writer  received  a request 
from  the  Editor  of  the  Tropical  Agriculturist  to 
review  the  61  interesting  communications  that  had 
been  forwarded  in  reply  to  the  Circular  issued,  ask- 
ing for  detailed  information  respecting  the  extent 
to  which  .VTannre  had  been  applie<l  to  tea. 
The  general  character  of  these  replies  appears 
to  indicate  that  manuringe  is  becoming  much 
more  general  upon  old  estates,  where  tea  has 
been  substituted  for  colf'ee,  but  that  upon  really 
good  soil  and  upon  new  estates,  it  has  not  yet 
been  resorted  to.  This  is  quite  what  should  be 
e.xpected,  and  also  shows  the  importance  of  con- 
sidering the  quality  or  chemical  composition  of 
the  soil  before  incurring  unnecessary  expense. 
In  this  country  as  recently  as  last  summer  in 
the  potato  experiments  at  Reading  on  Messrs. 
Sutton’s  trial  plots,  we  had  an  illustration  of 
the  folly  of  applying  certain  manures  to  soils 
already  fully  supplied  with  phosphoric  acid  and 
potash.  The  increase  in  yield  did  not  pay  for 
the  increase  in  the  cost  of  production,  and 
consequently  was  unremunerative.  Therefore, 
beore  commencing  any  expensive  system  of 
manuring  tea  estates,  it  is  essential  to  ascertain 
in  what  respect  the  suit  needs  assistance  whether 
in  regard  to  nitrogen,  potash  or  phosphoric  acid ; 
for,  in  regard  to  Lime,  we  need  not  trouble  to 
make  inquiry  as  it  is  not  specially  required  for  tea. 
Many  of  -the  writers  of  the  replies  state  in  a 
very  positive  manner  that  they  would  not 
think  of  manuring  tea  on  good  .soil,  and  they 
are  quite  right  both  practically  &nA  scientifically. 
It  is  rather  curious  to  notice  that  some  plan- 
ters .state  that  they  object  to  manuring  on  the 
ground  of  fearing  over  production.  One  can 
understand  the  objection  being  raised  upon  the 
ground  of  want  of  labour,  but  it  seems  a novel 
idea  to  fear  overproduction  in  a country  where 
new  estates  are  constantly  being  opened  up. 
Whether  manuring  should  be  resorted  to  or  not 
resolves  itself  into  a matter  of  cost.  In  estimating 
the  value  of  the  increased  yield  of  tea,  it  is 
however  important  to  remeniber  that  it  is  not 
the  gross,  but  the  net  extra  value  of  the  tea 
made  that  should  be  put  against  the  cost  of 
manuring.  This  was  pointed  out  by  the  writer 
when  reviewing  the  results  of  the  manure  ex- 
periments recorded  in  Mr.  Bamber’s  book.  Thus, 
if  the  ordinary  yield  of  400  lb.  made  tea  per 
acre  be  increased  to  600  lb.,  we  must  deduct 
the  cost  of  picking,  making,  packing  and  carri- 
age to  the  seaport,  and  not  simply  calculate 
that  200  lb.,  if  sold  in  Colombo  at  40  cents 
per  lb.,  would  realise  R80. 
At  present  it  appears  that  manuring  consists 
of  two  kinds,  bulky  and  concentrated  ; the  former 
being  represented  by  cattle-dung  and  line  refuse, 
a,n»t  the  latter  by  bones,  fish  and  castorcake. 
The  last  mentioned  are  described  somewhat 
erroneously  by  certain  planters  as  artificials, 
though  nothing  can  be  more  natural  than  the 
remains  of  animal  or  vegetable  productions  as 
natural  fertilisers.  These  three  fertilisers  are 
valuable  according  to  their  richness  in  phosphates 
of  Lime  and  Nitrogen  per  100  parts  as  follows 
Phosphates.  Nitrogen. 
Bone  Meal  50  to  53  3i  to  4 
Fish  Meal  14  to  18  6 to  74 
White  Castor  4 to  5 7 to  74 
Brown  Castor  3 to  4 4 to  44 
It  will  be  noticed  that  bones  are  highly  phos- 
phalic  with  comparatively  little  nitrogen,  and 
that  castor,  especially  the  superior  white  quality, 
is  highly  nitimmiious  and  only  very  slightly  phos- 
phatic,  while  fish,  which  is  often  of  very  vari- 
able quality  by  reason  of  adulteration  with  sand, 
occupies  a meilium  position. 
With  the  aid  of  the  local  Analyst  in  Colombo, 
planters  can  always  protect  themselves  at  a slight 
cost  against  being  imposed  u|)On  by  the  delivery 
of  inferior  materials,  yellerssoon  find  out  whether 
manures  are  subject  to  a careful  an  I systematic 
examination  by  analysis,  and  will  not  run  any 
risk  with  i ru'lent  buyers,  for  it  is  the  carele.ss 
and  thoughtless  buyer  that  is  usually  im|)osed  upon. 
Manuring  will  have  to  be  done  judiciously  (if 
it  is  to  be  prolitable),  regularly  ami  in  small 
quantity,  adapting  the  kind  of  manure  to  the  re- 
quirements of  the  soil.  If  nitrogen  only  is  required, 
castorcake,  well  crushed,  will  be  one  of  the 
cheapest  and  most  suitable.  It  phosphoric  acid, 
so  essential  to  the  production  of  a quick  growth  of 
leaf,  be  required,  a mixture  of  bonemeal  and  super- 
phosphate may  be  advantageously  applied.  If 
potash,  the  dominant  mineral  element  in  the  ash 
of  the  leaf,  be  required,  potash  salts  in  the  form  of 
sulphate  of  potash  should  be  supplied. 
The  use  of  nitrates,  whether  as  nitrate  of 
potash  or  as  nifiate  of  soJa,  which  apparently 
have  been  applied  to  a limited  extent,  should 
be  discouraged,  because  of  their  great  solubility 
and  the  known  heavy  rainfall  of  Ceylon.  These 
salts  readily  dissolve  in  their  own  weight  of 
water,  so  that  their  application  must  be  attended 
with  great  risk  in  a country  in  which  the  rain- 
fall is  sometimes  as  much  as  23  inches  in  24  hours. 
In  this  coutitry,  nitrate  of  soda  is  perhaps  the 
most  economical,  concentrated,  nitrogenous  manure 
that  can  be  employeil  upon  spring  sown  crops, 
which  have  only  a few  months  to  complete  their 
growth,  and  under  a rainfall  of  only  a few  inches 
per  mouth.  The  same  remark  may  apply  to  the 
use  of  sulphate  of  ammonia  and  also  to  Peruvian 
guano,  both  of  which  are  too  soluble  to  be  u.sed 
in  any  quantity  in  tea  fertilizers.  Those  ac- 
quainted with  the  hilly  districts  upon  which  tea 
is  grown  in  Ceylon  are  aware  of  the  terrible 
destruction  caused  by  wind  and  wash  and  that  the 
preservation  of  the  original  surface  soil  should  be 
the  first  consideration  of  the  careful  superin- 
tendent. The  richness  of  a soil  in  humus  or 
vegetable  mould  is  indicated  in  ordinary  soils 
by  the  richness  in  nitrogen  : the  best  Ceylon 
soils  contain  as  much  as  '50  in  100  parts  of  dry 
soil,  while  the  poor  soils  contain  only  -10  of 
nitrogen  per  100  parts  of  dry  soil.  And  as 
every  10  per  cent  repre.sents  in  round  numbers 
2 toils  per  acre  to  the  depth  of  one  foot,  it  will 
be  understood  that  the  dili'erence  between  the 
accumulated  fertility  of  one  soil  in  respect  of  only 
one  constituent,  namely  nitrogen,  as  compared  with 
another  soil,  may  vary  as  much  as  from  2 tons 
to  10  tons. 
