726 
Supplement  to  the  Tropical  i\gricult\u'ii<ty 
[Aphil  1,  1897. 
cocoa  in  Ceylon  plantations.  We  liuve  lieard  of 
the  foliage  of  the  latter — a common  native  hedge 
plant — being  used  for  green  manure  in  parts  of 
the  Island,  as  well  us  the  leaves  of  Ivepititiya 
(Croton  laccifermn),  Tejyhrosin  tinctoria  (pila), 
Callicarjia  lanata  (ilia)  and  other  trees.  In 
India,  plants  that  contain  a milky  juice  such  as 
Calotrojns  yujantea  (wara)  and  the  milk  hedge 
(Euphorbia  are  .‘specially  preferred  by  the 
ryot,  but  besides  these  various  otlier  plants  are 
favourite  manures.  The  following  are  among 
those  which  are  most  generally  employed  in 
India,  or  are  supposed  by  the  natives  to  have  some 
special  manurial  value  : Adhatoda  vanca  (Ada- 
thoda),  Calotropis  (jiyantoa  (wara),  Casmi  auri- 
culata  (Ranawura),  sjiecies  of  Datura,  Dodoncea 
viscosa  (Eta  werula),  Indujofera  })aucifolia,  Jatro- 
pha  curcas  (Rata  endaru),  Melia  azadriach, 
Mirabilis  jalapa  (Sendriku),  Ocimum  sanctum 
(Maduru  Tala),  Ponyamia  ylahra  (magiil  karanda). 
in  parts  of  India  Adhatoda  vasica  is  largely 
used  as  a vegetable  manure  for  paddy-fields,  and 
it  is  believed  to  possess  the  property  of  destroying 
low  forms  of  aquatic  vegetation  as  well  us  of  pro- 
tecting crops  against  insect  attack,  it  r\ould 
appear  that  a number  of  the  so-called  green  leaf 
manures  in  use  are  selected  for  certain  i>roperties 
they  possess  which  are  inimical  to  insect  life. 
Apart  from  their  action  as  fertilizers,  green  crop 
manures  are  valuable  agents  in  improving  the 
mechai’.ical  condition  of  both  cla^^eyand  sandy 
soils,  and  we  believe  that  by  a judicious  selection 
of  green  crops  and  leaves,  the  village  cultivator 
w'ill  be  in  uposition  to  mateiially  improve  his 
laud  and  increase  the  yield  of  his 
crops.  The  reference  to  the  result  of  grei  n 
leaf  manure  with  which  this  note  opens  only  goes 
to  prove  this  latter  fact.  In  the  light  of 
our  present  knowledge  of  the  mode  of  nutiition  of 
leguminous  crops,  we  would  ad\ isedly  look  for  our 
green  crop  fertilizers  among  the  members  of  this 
order  of  plants — to  w hich  erabadu,  dadap,  ilia, 
pila,  indigo,  ranawara,  and  magul  karunda  (the 
plants  already  referred  as  being  commonly  used 
for  the  purpose)  belong.  So  far  the  cultivator 
has  had  to  base  his  choice  on  his  own  e.x- 
perience  and  that  of  previous  generations.  He 
will  now  be  able  to  add  to  his  list  of  green  leaf 
manures  by  further  additions  from  the  legumi- 
nosie. 
In  this  connection  we  would  make  reference 
to  the  benefits  of  mi.ved  cropping,  not  carried  out 
in  the  slip-shod  manner  which  we  find  our  culti- 
vators adopting  in  their  chenas,  but  regularly 
and  in  order,  as  it  should  be.  The  .Superinten- 
dent of  the  Poona  Farm  has  been  e.xperimenting 
with  Dhall  (Cajanus  indicus)  as  a nursing  and 
foraging  plant  for  cereal  and  fodder  crops.  It  is 
advised  that  dhall  should  be  planted  four 
feet  apart  and  the  principal  crop  grow'ii  in  rows 
between  it.  Dhall  occupies  the  land  about  eight 
months  ; it  has  enormous  root  develojunent  and 
resists  drought  in  a remarkable  degive.  Its  long 
tap  roots  penetrate  the  soil  and  collect  plant  food 
there.  All  the  leaves  fall  as  the  crop  ripens,  and 
these  litter  enriches  the  surface  soil,  while  the  roots 
enrich  the  soil  with  nitrogen  got  from  the  atmo- 
sphere. These  characters  place  Dhall  in  the  fore- 
front us  a rotation  croj)  and  as  one  of  the  plants 
that  should  be  chosen  for  mixed  cro].jiing,  ])ar- 
ticularly  in  cereal  cultivation,  whether  for  grain  or 
fodder.  The  Indian  Ayriculturist,  referring  to 
the  Poona  experiments,  truly  remarks  that 
leguminous  crop-;  of  the  jiapilionaceous  sub- 
order are  the  best  to  rotate  with  cereals, 
because  through  the  influence  of  bacteria 
existing  in  the  tubercles  on  the  roots  of  these 
puke  crops,  irce  nitrogen  is  taken  from  the 
atmosphere  andconveried  into  an  organic  com- 
pound of  nitrogen.  This  combined  or  organic 
nitrogen  becomes  available  ns  plant-food  as  the 
root  residues  of  leguminous  cro].s  decay  in  the 
soil.  “ The  growth  of  leguminous  crops  with 
cereals  in  rotation,  or,  as  is  more  common  in 
India,  as  a mixed  crop”,  says  our  Indian  contem- 
poraiy,  “ has  probably  done  more  to  raise  the 
fertility  of  Indian  soils  than  any  other  cause.”  It 
is  a fact  that  many  of  the  jjaiiilionaceje  are  not 
only  laseful  as  rotation  or  mixed  crops,  but  also 
provide  excellent  green  fodder  for  milch  or  other 
cattle. 
We  believe  that  much  good  can  be  done  by 
teaching  cultivators  how  to  make  use  of  green 
leaf  and  croj)  manures,  to  the  best  advantage  and 
persuade  them  to  adopt  an  a])proved  system  of 
mixed  cro]iping  in  their  chenas,  using  such  a 
fertilizing  croj)  as  dhall,  which,  at  the  same  time, 
will  add  materially  to  the  poor  stock  of  food  at 
the  disposal  of  the  villager  in  the  remoter  parts 
of  the  Dhuid, 
OCCASIONAL  NOTES. 
Hr.  .Alenon,  of  the  College  of  Agriculture,  Sai- 
dapet,  and  at  one  time  connected  with  the 
Colombo  School  of  Agriculture,  paid  us  a visit 
last  moiitli  on  his  way  hack  from  England  to 
India.  Hr.  Henon  has  been  spending  some  two 
years  at  the  iiriucijml  agricultural  centres  in 
Great  Britain  and  on  the  Continent,  and  has  de- 
rived a deal  of  valuable  exjierience  thereby. 
The  students  composing  the  new'  Forestry  class 
are  Hessrs.  Fontyn,  Jvarunaratne,  11.  S.  Dias,  R. 
de  Silva,  L.  ilendis  and  H.  A.  Fernando.  The 
work  of  the  class  commenced  on  the  1st  prox. 
Preparations  are  in  i.rogress  for  a trial  with 
imported  varieties  of  Indian  paddies,  The 
plougliing  which  is  now  going  on  is  being  done 
with  a light  iron  plough  made  locally. 
The  “ Green  Bank  dairy  in  Jail  Rood  w'hich  was 
started  a month  ago  on  a small  scale  is,  we  hear, 
being  gradually  extended.  The  increase  in  the 
number  of  belter  clas.-;  dairies  goes  to  prove  that 
there  is  a ri.sing  demand  for  good  milk  in  the  city, 
and  also  that  dairying  if  intelligently  carried  on  is 
a remunerative  industry. 
DR.  KOCH’S  INVESTIGATIONS  INTO 
THE  CAUSE  OF  RINDERPEST. 
INTRODOCTOHY. 
The  Agricultural  and  Veterinary  Journals  are 
largely  occuined  with  the  subject'  of  rinderpest 
which  has  been  once  again  brought  prcminentlV 
into  notice  by  the  devastation  that  the  plague 
has  caused  in  South  Africa.  It  will  be  remem- 
