366 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
October  15,  1903. 
Manuring  Potatoes. 
In  the  year  1900  a  very  large  number  of  experiments  were 
conducted  on  Scottish  farms,  under  the  auspices  of  the 
West  of  Scotland  Agricultural  College.  The  tests  covered 
the  fattening  of  sheep  and  cattle  ;  the  manuring  of  hay, 
Turnips,  and  Potatoes ;  rotation  manuring ;  and  the  com¬ 
parative  merits  of  varieties  of  Oats.  The  official  report 
(which  we  have  read  with  great  pleasure  and  interest)  is  a 
most  exhaustive  one,  and  well  worthy  of  the  attention  of 
all  agriculturists.  But  there  are  some  results  of  these  ex¬ 
periments  which  are  so  striking  as  to  justify  special  mention 
here.  These  are  connected  with  the  manuring  of  Potatoes, 
and  are  the  more  remarkable  inasmuch  as  the  experiments 
with  manuring  Turnips  were  particularly  barren  of  useful 
results. 
Varioas  manures  were  tried'on  two  varieties  of  Potatoes, 
viz.,  Maincrop  and  Up-to-Date.  On  sixteen  different 
farms,  on  ten  of  which  Maincrop  was  gi’own,  and  on  six 
Up-to-Date,  on  each  field  a  piece  was  left  unmanured ; 
another  was  manured  with  twenty  loads  per  acre  of  farm¬ 
yard  manure ;  another  with  ten  loads  farmyard  manure, 
4  cwt  superphosphate,  1  cwt  sulphate  of  ammonia,  and  1^ 
cwt  of  sulphate  of  potash  ;  and  still  another  plot  with  6 
cwts  superphosphate,  2  cwts  sulphate  of  ammonia,  1  cwt 
nitrate  of  soda,  and  2  cwts  of  sulphate  of  potash.  As  the 
results  are  taken  from  the  average  of  ten  farms  in  the  case 
of  Maincrop,  and  six  in  that  of  Up-to-Date,  they  may  be 
accepted  as  being  conclusive,  not  only  with  regard  to  the 
cropping  qualities  of  the  two  Potatoes,  but  as  to  the  effect 
of  manure  on  the  crops  generally,  and  the  two  Potatoes, 
individually. 
On  the  unmanured  plots  the  average  produce  of  Main- 
crop  was  tons  ;  of  Up-to-Date,  4f  tons.  Gi'own  with 
farmyard  manure  only,  Maincrop  produced  6  tons  3  cwt,  an 
increase  of  2  tons  13  cwt ;  but  Up-to-Date  produced  9  tons 
6  cwt,  an  increase  of  4  tons  12  cwt,  or  nearly  double  that 
produced  by  the  unmanured  plot. 
With  ten  loads  manure,  and  the  smaller  quantity  of 
artificials,  the  results  as  regards  Maincrop  were  practically 
identical  with  those  from  farmyard  manure  (twenty  loads)  ; 
and  the  same  were  obtained  again  from  the  large  applica¬ 
tion  of  artificials  only ;  but  Up-to-Date,  though  responding 
well  to  the  influence  of  the  artificials,  did  not  quite  equal 
its  own  results  from  the  twenty  loads  of  muck  alone  ;  the 
returns  frorn  the  manure  and  artificials,  and  from  artificials 
only,  being  identical,  and  in  each  case  half  a  ton  below  the 
all-manure  application. 
In  addition  to  ascertaining  the  total  cropping  results, 
careful  note  was  also  taken  of  the  effect  of  the  manures  on 
the  quality  of  the  tubers,  but  only  in  connection  with  the 
Maincrop  variety.  The  results  here  are  decidedly  startling, 
for  it  has  been  an  axiom  amongst  old  Potato  growers  that 
the  influence  of  artificials  was  against  quality,  and  there  has 
been  great  prejudice  against  their  use  on  that  account. 
We  imagine  that  this  idea  has  grown  through  observation 
of  the  effects  of  nitrogen  used  alone,  and  that  other  well 
balanced  mixtures  have  shared  in  the  condenmation. 
As  a  .  general  result  of  these  experiments,  it  is  conclu¬ 
sively  proved  that  20  tons  of  farmyard  manure  produce  a 
very  small  increase  over  the  quantity  produced  by  10  tons 
{both  without  artificials),  the  money  return  being  11s.  7d.  per 
ton  for  the  first  10  tons,  and  only  3s.  3id.  per  ton  for  the 
second  10  tons !  Not  only  is  this  the  case,  but  analyses  of 
the  samples  proves  that  the  tubers  produced  by  the  smaller 
dressing  are  of  firmer  texture  and  higher  quality  than  the 
others,  and  it  necessarily  follows  that  the  quantity  of 
manure  which  may  be  applied  profitably  to  the  Potato  crop 
is  strictly  limited,  and  that  it  is  not  much  more  than  10  tons 
per  acre. 
We  have  ourselves  applied  twelve  loads  per  acre  syste¬ 
matically  for  a  number  of  years,  previous  observation  having 
taught  that  that  quantity  was  the  best  mean  to  stick  to. 
W  e  have  proved  eight  loads  to  be  too  little,  and  though  we  < 
were  never  so  extravagant  as  to  use  twenty  loads,  we  have 
seen  neighbours  do  so  ;  but  the  results  ii.ever  convinced  us 
that  twelve  loads  were  not  enough.  Ot  course,  we  used 
artificials  as  well,  and  we  fancy  that  eight  loads  more 
manure,  with  the  attendant  labour,  may  very  economically 
have  25s.  worth  of  artificial  manure  substituted  for  it,  and 
leave  a  like  sum  saved  to  the  banking  account. 
But  we  have  wandered  away  from  the  question  of  quality. 
The  percentages  of  starch  contained  by  the  various  samples 
were  as  follows  : 
No  manure :  starch,  18.24.  Twenty  tons  farmyard 
manure  alone,  17.38. 
Ten  tons  of  farmyard  manure  alone,  17.92.  Ten  tons 
yard  manure  with  artificials,  18.36. 
Artificial  manures,  18.70. 
Here  is  striking  evidence  that  artificials  tend  to  improve 
the  quality,  whilst  yard  muck  has  an  opposite  effect.  The 
more  muck  is  used  the  lower  is  the  quality  of  the  crop. 
It  is  remarkable,  also,  that  on  the  “  no  manure  ”  plots  the 
quality  is  not  so  good  as  on  the  artificial  manure  plots  ; 
although  it  is  considerably  better  than  the  yard  manure 
pieces. 
There  is,  however,  one  point  to  be  borne  in  mind,  and 
that  is,  that  these  satisfactory  results  were  produced  by  a 
mixture  in  which  the  potash  took  the  form  of  commercially 
pure  sulphate  of  potash.  Separate  experiments  were  carried 
on  to  compare  the  effect  of  the  various  forms  of  potash,  and 
when  muriate  of  potash^  kainit,  and  sulphate  of  potash  were 
used  with  other  artificials,  but  against  each  other,  it  was 
found  that  not  only  did  sulphate  of  potash  produce  the  best 
quality  of  Potatoes,  but  that  it  was  the  most  effective  form 
of  potash  to  use  in  conjunction  with  farmyard  manure. 
It  is  evident  from  a  very  brief  review  of  the  chief  points 
in  this  report  of  the  West  of  Scotland  Agricultural  College 
that  very  good  and  careful  work  is  being  carried  on  by  it ; 
and  the  results  of  its.  labours,  especially  with  regard  to  the 
experiments  on  Potatoes,  should  be  most  encouraging  to 
Scottish  Potato  growers  ;  for  they  conclusively  prove  that 
success  does  not  depend  upon  an  inexhaustible  supply  of 
farmyard  muck,  but  that  valuable  crops  may  be  grown  with¬ 
out  any  at  all ;  and  that  the  increase  of  the  Potato  acreage 
is  only  limited  by  the  arable  land  available  and  the  supply 
of  necessary  labour.  The  last  item  is  the  real  difficulty,  for 
Potatoes  employ  much  labour.  In  most  seasons  Great 
Britain  can  easily  provide  her  own  Potato  supply ;  and  by 
the  encouragement  of  this  industry  our  legislators  can  do 
more  than  in  any  other  way  to  keep  the  people  on  the 
land.  .  , 
Work  on  the  Home  Farm. 
We  are  still  going  through  experiences  of  storm  and  flood. 
Some  farmers  are  trying  to  thr«sh,  and  others  to  lift  Potatoes, 
with  ill  success  in  either  case.  Many  Potato  fields  are  being 
commenced  before  the  Potatoes  are  fit,  because  the  Irish  hands 
would  Avait  no  longer.  It  VA  as  a  case  of  “  sta.rt  work  or  we  go.” 
It  is  difficult  to  ascertain  the  facts  as  regards  the  progress  of  the 
disease,  but  there  can  be  no  doubt  it  is  very  serious.  We  can 
A’ouch  for  the  fact  that  in  at  least  tAvo  instances  the  epidemic 
has  made  rapid  progress  in  the  pie,  there  having  been  very  little 
to  see  of  it  Avhen  the  Potatoes  Avere  lifted.  We  are  giving  ours 
time  in  the  ground,  so  that  the  Avorst  may  be  past  before  we 
touch  them.  We  hear  of  many  Avaggons  of  Potatoes  coming  back 
by  rail  to  the  groAvers,  having  been  refused  by  the  consignees. 
Growers  must  necessarily  fight  shy  of  risking  immediate  de¬ 
livery,  under  such  circumstances,  and  Ave  advise  all  sellers  to 
act  very  cautiously.  The  safest  plan  is  to  deliver  to  the  buyers’ 
order  only  at  the  sellers’  station. 
We  hear  Evergoods  are  good  and  sound,  hut  Empress  Queen 
is  not  so  hardy  as  might  be.  We  hope  to  be  able  to  speak  with 
some  authority  on  thei  new  kinds  A'ery  shortly. 
We  are  sorry  to  say  that  stacks  are  threshing  out  in  very 
poor  condition,  and  A^ery  few  of  the  new  samples  are  at  all  satis¬ 
factory.  The  driest  Wheat  fetches  2os.  6d.,  and  some  of  the 
damp  rubbish  can  be  bought  for  21s.  Barley  makes  from  20s. 
to  24s.,  but  none  of  it  Avill  make  malt  unless  it  is  previously 
dried.  We  have  not  yet  .seen  a  sample  of  Wheat  dry  enough  for 
soAving,  and  seed  time  is  close  at  hand. 
Bad  weather  and  unfaA’ourable  corn  markets  have  combined 
to  cause  a  decided  slump  in  the  sheep  market.  Needy  sellers 
Avant  money,  and  the  needy  buyers  are  hindered  from  raising 
any,  and  there  is  a  deadlock.  Our  lambs  are  doing  nicely  on 
Turnips,  Avhich  are  firm  and  good,  hut  Ave  have  seen  larger  roots 
and  heavier  crops.  The  lambs  look  full  and  Avell  and  very 
bright  in  their  skins.  They  are  still  eating  ^Ib  of  lamb  food  per 
head.  It  is  rather  expensive,  and  Ave  shall  gradually  reduce  it 
by  half  and  substitute  a  little  Clover  in  the  rack. 
