The  Woburn  Field  Experiments,  1909. 
379 
Experiment  with  Magnesia  on  Wheat  {Lansome 
Field),  1909. 
Following  up  experiments  conducted  at  the  Pot-culture 
Station,  which  went  to  show  that,  as  the  proportion  of  magnesia 
to  the  lime  contained  is  increased,  so  the  crop  suffers  in  growth 
and  the  grain  undergoes  modification,  it  was  determined  to 
carry  these  out  also  on  the  field  scale,  and  an  area  was  set 
apart  for  the  purpose  in  Lansome  Field  in  1908.  Now  it  is 
obvious  that,  whereas  in  a pot-culture  experiment  it  is  easy  to 
vary  the  proportion  of  magnesia  to  lime  at  pleasure  and  get 
results  in  a single  season,  this  is  not  possible  in  a field  experi- 
ment. Starting  with  a soil  containing  definite  percentages  of 
magnesia  and  lime  (that  of  Lansome  Field  was  as  1 : 2)  it  would 
need  very  heavy  and  often  impracticable  amounts  of  magnesia 
to  be  applied  in  order  to  materially  alter  the  balance  of  constitu- 
ents. Hence  it  was  felt  that  under  field  conditions  the  experi- 
ment would  have  to  be  continued  for  some  time.  The  quantities 
of  magnesia  (MgO)  applied  for  the  wheat  crop  of  1908  were 
3 cwt.  per  acre  and  6 cwt.  per  acre.  The  harvest  results,  as 
expected,  did  not  show  anything  marked  as  regards  difference 
of  crop  weights,  but  the  produce  of  each  plot  was,  by  the 
kindness  of  Mr.  A.  E.  Humphries,  of  Coxes  Lock  Mill,  Wey- 
bridge,  submitted  by  him  to  practical  milling  and  baking  tests. 
As  these  are  to  be  continued,  and  will  be  dealt  with  later,  it 
will  be  sufficient  to  say  here  generally  that  Mr.  Humphries, 
without  any  previous  knowledge  of  what  each  lot  represented, 
was  able  to  place  them  in  order,  his  examination  showing  that 
as  the  amount  of  magnesia  in  the  soil  was  increased,  so  was  the 
inferiority  of  the  grain,  as  judged  by  milling  and  baking  tests, 
more  marked.  These  results,  confirming  as  they  did  the 
observations  in  the  Pot-culture  work,  were  considered  of  much 
importance,  and  so  the  experiments  were  continued  in  1909. 
Wheat  was  again  sown  on  five  plots  in  Lansome  Field  on 
November  19, 1908,  the  variety  grown  being  “ Street’s  Imperial,” 
obtained  from  Driffield,  Yorks.  To  it  superphosphate,  3 cwt. 
per  acre,  and  sulphate  of  potash,  1 cwt.  per  acre,  were  given, 
and  magnesia  (ground  fine)  was  top-dressed  on  November  26, 
at  the  rate  of  1^  cwt.  per  acre.  During  the  growth  of  the  crop 
it  was  noticed  that  where  magnesia  had  been  applied  the  soil 
had  a darker  colour  than  the  rest,  and  seemed  to  be  rather 
more  “ sticky  ” and  to  remain  moister.  The  crop  was  cut 
on  August  2.5,  1909.  The  harvest  results  are  given  in  Table 
VIII.,  pap  380. 
Examining  these  results  it  may  be  said  that  they  are  not 
very  marked  as  regards  plots  1 and  2,  in  comparison  with  plot  5, 
which  received  no  magnesia,  but  the  figures  of  plots  3 and  4, 
