10 
SIR J. B. LAWES AND PROFESSOR J. H. GILBERT ON THE 
The deeper rooting, and freer growing MeliJotus leucantha gave more or less pro¬ 
duce in each year of the eight, large crops in 1879 and 1882, a total yield of nitrogen 
over the eight years of 565 lbs. per acre, and an average annual yield of 71 lbs. 
Lastly, the still deeper rooting, and still freer growing Medicago sativa, sown first 
in 1879, gave no crop in that year, only small crops in 1880 and 1881, and then 
rapidly increasing amounts, until the yield of nitrogen was estimated at 337 lbs. per 
acre in 1884, and at 233 lbs. in 1885 before the soil sampling, and 37 lbs. afterwards, 
making a total for that year of 270 lbs. The total yield of nitrogen in the 6 years, 
prior to the soil sampling, was 880 lbs. ; giving an average over the 8 years of 
110 lbs., or over the 6 years when there was any crop, of 147 lbs. of nitrogen per 
acre per annum. 
Table IV. shows the amounts of nitrogen as nitric acid found in the soils and 
subsoils of the different plots—in all cases calculated into lbs. per acre. 
Table IV.-—Nitrogen as Nitric Acid per acre, lbs., in the soils and subsoils of some 
experimental plots, without nitrogenous manure, for more than 30 years. 
Hoosfield, Rothamsted. Samples collected July 29 to August 14, 1885. 
Unmanured. 
Series I. 
Mineral manures only. 
Trifolium 
+ or — 
Trifolium repens. 
Depths. 
i 
Wheat- 
fallow land. 
Trifolium 
repens. 
Plot 5. 
Melilotus 
leucantha. 
Plot 5. 
Medicago 
sativa. 
Plot 5. 
repens. 
+ or — 
Wheat land. 
Melilotus 
leucantha. 
Plot 5. 
Medicago 
sativa. 
Plot 5. 
[ inches. 
lbs. 
lbs. 
lbs. 
lbs. 
lbs. 
lbs. 
. lbs. 
1- 9 
17-44 
11-50 
4-35 
8-88 
- 6-94 
- 7-15 
- 2-62 
10- 18 
3-67 
1-38 
1-40 
1-11 
- 2-29 
+ 0-02 
- 0-27 
19- 27 
2-76 
0-90 
2-12 
0-78 
- 1-86 
+ 1-22 
- 0-12 
28- 36 
2-16 
1-86 
2-94 
0-81 
- 0-30 
+ 1-08 
- 1-05 
37- 45 
1-68 
7-08 
5-22 
0-99 
+ 5-40 
- 1-86 
- 6-09 
46- 54 
1-47 
11-31 
6-21 
0-93 
+ 9-84 
- 5-10 
-10-38 
; 65- 63 
1-77 
13-14 
7-95 
0-57 
+ 11-37 
- 5-19 
-12-57 
64- 72 
1-83 
12-63 
10-08 
0-81 
+ 10-80 
- 2-55 
-11-82 
73- 81 
2-29 
11-19 
9-66 
0-70 
+ 8-90 
- 1-53 
-10-49 
82- 90 
2-01 
10-70 
9-16 
0-61 
+ 8-69 
- 1-54 
-10-09 
91- 99 
1-98 
11-08 
8-83 
0-44 
+ 9-10 
- 2-25 
-10-64 
100-108 
2-06 
9-96 
10-12 
0-41 
+ 7-90 
+ 0-16 
- 9-55 
Total .... 
41-12 
102-73 
78-04 
17-04 
+ 61-61 
-24-69 
-85-69 
1 
Summary and control. 
]- 9 
17-44 
11-50 
1 
4-35 1 
8-88 
- 5-94 
- 7-15 
- 2-62 
10- 18 
3-67 
1-38 
1-40 ' 
1-11 
- 2-29 
+ 0-02 • 
- 0-27 
Mi^eture of 1 
19-108 inches / 
20-63 
88-02 
73-21 
6-97 
+ 67-39 
-14-81 
-81-05 
Total .... 
41-74 
100-90 
78-96 i 
16-96 
+ 59-16 
-21-94 ■ 
-83-94 j 
