110 
KA'periments  of  the  late  Me.  .Tames  Mason. 
Tile  follovvino-  Tables  sliow  some  typical  n>sults  olitained  ; 
of  course  with  such  small  areas  tlu'  estimated  yields  per  acre 
are  excessive,  since  the  plants  can  push  freely  into  the  Aacant 
sjiace  round  each  plot. 
Tank  1. 
Crop 
Year 
Yield  per  acre 
Dry  weight 
Nitrogen 
Red  clover 
18'.)0 
Cwt. 
20 
Lb. 
52 
18‘Jl 
40 
104 
Wheat 
1892 
27 
70 
181)3 
43  (30  bushels  grain) 
40 
Barley 
1894 
17  (17  bushels  grain) 
19 
In  this  case  three  years’  growth  of  red  clover  not  only 
yielded  in  the  hay  220  lb.  per  acre  of  nitrogen  derived  from 
the  atmosphere,  but  left  behind  in  the  soil  sufficient  nitrogen 
to  grow  a normal  crop  of  wheat  containing  40  lb.  per  acre  of 
nitrogen,  followed  by  a small  crop  of  barley  containing  another 
19  lb.  The  latter  crop  showed  that  the  accumulations  were 
becoming  exhausted,  so  the  tank  was  sown  again  with  clovers. 
Tank  4. 
Crop 
Year 
A’ield  per  acre 
Dry  weight 
Nitrogen 
Cwt. 
Lb. 
Alsike 
1890 
34 
137 
1891 
56 
221 
1892 
2 
8 
1893 
38 
150 
1894 
12 
48 
Oats 
1895 
42  (52  bu.shels  corn) 
56 
In  this  case,  in  five  years,  three  good  crops  of  Alsike  were 
grown,  which  provided  564  lb.  of  nitrogen  per  acre  in  the 
hay,  and  enabled  the  soil  to  carry  in  the  sixth  year  a crop 
of  oats  containing  56  lb.  of  nitrogen  per  acre. 
Another  of  the  tanks  was  sown  with  an  ordinary  mixture 
of  seeds  for  permanent  pasture  ; for  ten  seasons  it  yielded  fair 
crops,  chiefly  of  clover,  but  as  the  clovers  died  out  the  yield  of 
