302  The  Woburn  Field  Experiments,  1903. 
Table  XL — Grass  Experiments  {Broad  Mead). 
Produce  of  Hay,  1903. 
Plot 
Manures  per  acre 
Weight  of  hay 
per  acre 
1 
Basic  slag,  10  cwt.  ; nitrate  of  potash,  1 cwt. 
T.  c.  q.  lb. 
2 0 1 16 
2 
Mineral  superphosphate,  5 cwt. ; sulphate  of  potash,  1 cwt. 
2 3 1 24 
3 
Basic  slag,  10  cwt.  ; sulphate  of  potash,  1 cwt. 
2 1 
1 24 
4 
No  manure  ......... 
1 14  3 0 
5 
Lime,  2 tons  ......... 
1 15  0 8 
6 
Farmyard  manure,  12  tons  ...... 
2 3 
3 20 
of  potash)  seemed  to  be  the  best  eaten,  and  the  dung  plot  (6) 
the  roughest  of  all.  The  hay  crop  on  plot  6 (dung)  was,  with 
that  from  plot  2 (superphosphate  and  sulphate  of  potash),  the 
heaviest,  the  other  plots  where  potash  was  used  in  some  form 
also  giving  increased  yields.  The  lime  (plot  5)  gave  no  increase, 
but  undoubtedly  had  sweetened  the  herbage.  It  is  worthy  of 
note  that  in  previous  experiments  conducted  in  this  same  field 
neither  basic  slag  nor  superphosphate  had  shown  any  benefit, 
but  now  that  potash  was  added  as  a constituent,  a decided 
improvement  was  shown.  This  was  even  more  marked  than 
the  mere  weights  of  crop  would  indicate,  for,  on  going  over 
the  plots,  the  botanical  differences  were  strongly  evidenced, 
clover  having  much  increased  wherever  potash  had  been 
applied.  Through  the  kindness  and  at  the  suggestion  of 
Mr.  A.  D.  Hall,  Director  of  the  Eothamsted  Experimental 
Station,  samples  of  the  grass  when  cut  were  submitted  by 
him  to  botanical  separation  at  the  Rothamsted  laboratory,  and 
the  results  are  set  out  in  Table  XII.,  page  303. 
From  these  interesting  figures  it  will  be  seen  that  the  appli- 
cation of  potash  manures  has  already  had  a marked  influence 
in  increasing  the  amount  of  clovers,  especially  on  plot  2,  which, 
taken  in  conjunction  with  the  weight  of  hay,  has  certainly 
given  the  best  return.  Another  point  brought  out  is  that, 
though  farmyard  manure  has  given  a heavy  crop,  this  has  been 
at  the  expense  of  the  clovers,  and  consists  mostly  of  the  more 
vigorous  grasses.  Lime,  on  the  other  hand,  has  increased  the 
clovers  and  generally  sweetened  the  pasture. 
Pkevention  of  Potato  Disease  {Butt  FuRLoyG),  1903. 
A series  of  experiments  on  this  question,  combined  with 
which  was  a manurial  experiment,  was  carried  out  on  Butt 
Furlong  field  in  1903,  but,  owing  to  the  unfavourable  season, 
the  potatoes  were  a very  poor  crop,  and  the  crop  weighings, 
though  taken,  would  be  misleading,  and  so  are  not  given. 
The  varieties  grown  were  “ British  Queen,”  “ Challenge,”  and 
