74 
SIR J. B. LAWES AND PROFESSOR J. H. GILBERT ON THE 
Total Nitrogen in the Crops of 1886. 
“ 
C ” series, unwashed sand. 
“ B ” series, 
washed sand. 
Oats. 
Lupins. 
Field- 
beans. 
Fed 
clover. 
Sand-peas. 
I. Unmanured. 
grams. 
U-37J 
grams. 
2-797 
grams. 
2-478 
grams. 
3-396 
grams. 
0-488 
2. Mineral manure. 
0-.388 
9-572 
4-689 
8-.352 
2-389 
.3. Mineral manure, and 0’832 gram N . 
1-136 
5-39-2 
3-232 
8-803 
3-698 
4. Mineral manure, and 3'328 grams N 
3-486 
8-816 
4-104 
9-403 
5-069 
It should be obseived that the quantities of nitrogen in manure, as stated in the 
table, relate to the “ C ” Series in unwashed sand, but the quantities supplied to 
the smaller vessels of the “B” Series for the sand-peas were for Experiment 3, 
0'416 gram, and for Experiment 4, 1’664 gram. On the results, Wolff remarks 
that without exception the cereal crop (oats) only flourished when there was a 
sufficient quantity of nitrogenous nutriment (nitric-nitrogen) available; whilst the 
Leguminosse for the most part grew quite as luxuriantly without, or with very little, 
nitrogen in the soil, provided the ash constituents were in abundance. Potatoes, on 
the other hand, like the oats, required combined nitrogen to be provided within 
the soil. 
The mineral composition of the crops, and the influence of the varying climatal 
conditions of the three seasons, are discussed in some detail. Estimates are given of 
the amounts of phosphoric acid, potash, &c., in the crops, calculated per hectare ; and 
the quantity of nitrogen in the oat crop is estimated to correspond, in one case, to 
139'4 kilog. per hectare (= 124‘5 lbs. per acre), which is very large. 
Excluding the experiments in the unwashed sand, the mean of 7 experiments under 
each condition of manuring with oats, and of 22 under each condition witli different 
Leguminosae, shows the following amounts of air-dried produce :— 
Oats. 
Mean of 
7 experiments in 
each case. 
Legumino.sae. 
hlean of 
22 experiments in 
each case. 
c:rams. 
^rams. 
16-87 
22-71 
18-31 
68-53 
47-42 
73-39 
110-74 
74-95 
1. Unmanured. 
2. Alineral manure. 
2 f Mineral manure, and 0'2.38 gram nitrogen for 
[ the oats, and 0T80 gram for tlie LeguminosiP 
^ r Mineral manure, and 0 952 gram nitrogen for 
\ the oats, and 0‘72 gram for the LeguminosEe 
