156 
INVESTIGATIONS ON ROTHAMSTED SOILS. 
success, for nearly thirty years. Of the plants originally chosen to 
succeed the clover several failed, and were discontinued, but others 
were successfully continued, notably Trifolium repens (white clover), 
Vicia saliva (vetches), Melilotus leucantha (Bokhara clover), and 
Medicago sativa (lucern). These crops were grown from 1878 down 
to 1898 in various series of plats, one series getting various mineral 
fertilizers only, while a second, third, and fourth series received 
respectively (in addition to various minerals as in the case of the first 
series) sodium nitrate, ammonium salts, and rape cake. In 1898 all 
but the plats of series 1 were plowed up, and wheat grown on them 
during 1899 and 1900. Series 1, however, is continued under legu- 
minous cultivation. 
This will probably be sufficient preface to the analytical soil results, 
to which attention is now to be drawn. 
The samples analyzed were collected in 1881, 1882, and 1883 from 
the wheat-fallow land and from various leguminous plats of the series 
receiving annually only mineral fertilizers without any manurial sup- 
ply of nitrogen. 1 It will be seen that in many cases samples have 
been taken down to twelve successive depths of 9 inches, i. e., to a 
depth in all of 9 feet. In these various samples both the organic 
nitrogen and the nitric nitrogen were determined. The full details of 
these analyses are given in the following table, the quantities being 
stated as percentages (parts per million in the case of the nitric nitro- 
gen) and as pounds per acre. 
We will first look at the organic-nitrogen results. 
Table 84. — Hoos field fallow wheat and leguminous land — Samples collected in 
1881, 1882, 1883, and 1885— Organic nitrogen residts. 
ADOPTED WEIGHTS OF FINE DRY SOIL PER ACRE. 
Depth. 
Samples col- 
lected 
March, 1881. 
Samples col- 
lected July 
26-31,1882. 
Samples col- 
lected July 
17-26,1883. 
Samples col- 
lected July 
29- Aug. 14, 
1885. 
First 9 inches 
Pounds. 
2,650,000 
2, 700, 000 
2,900,000 
Pounds. 
2, 050,000 
2, 700,000 
2, 900. (HID 
3,000,000 
3,000,000 
3,000,000 
Pounds. 
2,650,000 
2,700,000 
2,900,000 
3,000,000 
3,000,001) 
3,000,000 
3,000.000 
3,000,000 
2,900,000 
2, 750, 000 
2,750,000 
2,750,000 
Pounds. 
2, 650, 0(H) 
2,700,000 
2.900,000 
3,ooo,o;k) 
3,000,000 
;i. oiio.ooo 
3,000,000 
3,000,000 
2.90O.0O0 
2.750,0IM 
2,75(1.(1(1 i 
2, 750, (.00 
Third 9 inches 
Sixth 9 inchus. 
2,650,000 
2, 70(1, (Kill 
29, 050, (MM) 
2, 650. on i 
2, 700, 00; I 
29,050,001) 
Total 
34, 400. (XX) 
34,400,000 
1 For full manorial details for the various plats, see the Rothainsted Memoranda. 
