412 
Clover as a Preparatory Crop for Wheat. 
The three layers of soil, dried and reduced to powder, were 
mixed together, and a prepared average sample, when submitted 
to analysis, yielded the following results. 
Composition of Clover-scil, 18 inches deep, from part of 11-acre fieldy_ 
twice mown for hay. 
/■Organic matter 5'SG 
Oxides of iron G"83 
Alumina 7"12 
Carbonate of lime 2'13 
Mamesia 2-01 
-§•5 
Potash 
Soda 
Chloride of sodium . . 
Phosphoric acid 
Sulphuric acid 
( Insoluble siliceous matter 
Consisting of : — Alumina 
Lime (in a state of silicate) 
Magnesia 
Potash 
Soda 
74-61 
•07 
•08 
•02 
•IS 
, -11 
4-37 
. 4-07 
•46 
•19 
•23 
Silica 65-29 
99^68 
This soil, it will be seen, contained in appreciable quantities 
not only potash and phosphoric acid, but all the elements of fer- 
tility which enter into the composition of good arable land. It 
may be briefly described as a stiff clay-soil, containing a suffi- 
ciency of lime, potash, and phosphoric acid to meet all the re- 
quirements of the clover-crop. Originally rather unproductive, 
it has been much improved by deep culture ; by being smashed 
up into rough clods early in autumn, and by being exposed in 
this state to the crumbling effects of the air, it now yields good 
corn and forage crops. 
In separate portions of the three las ers of soil, the proportions 
of nitrogen and phosphoric acid contained in each layer of 
G inches were determined and found to be as follows : — 
Soil dried at 212° Fiihr. 
1st, 6 inches. 2iid, 6 inches. 3rd, 6 inches. 
. ^249 .. .. •134 .. .. ^172 
. •162 .. .. ^092 .. .. ^064 
. •igS .. .. ^112 .. .. -078 
Percentage of phosphoric acid 
Nitrogen 
Equal to ammonia 
In the upper 6 inches, as will be seen, the percentage of 
both phosphoric acid and nitrogen was larger than in the two 
following layers ; while the proportion of nitrogen in the 
6 inches of surface soil was much larger than in the next 6 
inches ; and in the third section, containing no visible particles 
of root-fibres, only very little nitrogen occurred. 
In their natural state the three layers of soil contained — 
