Field Experiments on Root-Crops. 
375 
Resui-ts of Swede Expeiumests at Blexxeriiasset Farm, Carlisle, 
ia 1869. 
Plots of 
each. 
10 
11 
12 
Manures and Quantities per Acre. 
No manure 
Mineral Superphosphate . 
Mineral Superphosphate , 
and 
Muriate of Potash . . 
Mineral Superphosphate . 
and 
Peruvian Guano 
Peruvian Guano 
No Manure 
Mineral Superphosphate , 
and 
Muriate of Potash . . 
and 
Sulphate of Ammonia 
Kotten Dung , . . . 
Mineral Superphosphate . 
and 
Muriate of Potash . . 
and 
Nitrate of Soda 
Kotten Dung .. .. 
and 
Mineral Superphosphate 
Bone Dust 
and 
Superphosphate 
No Manure 
1 
tons 
20 
cwts. 
3 
1 
tons 
10 
cwts. 
15 
3 
u 
Produce of 
Clean Swedes 
per Acre. 
Increase over 
average produco 
of 
Unmanured Plots. 
No. 1. and No. 6. 
tons cwts. qrs. 
12 0 0 
13 7 2 
15 15 
18 
21 
0 
15 10 0 
15 12 2 
14 10 0 
18 12 
23 10 0 
18 12 2 
16 10 0 
tons cwts. qrs. 
0 0 0 
0 2 2 
2 10 0 
0 0 
10 5 0 
4 17 2 
7 17 2 
5 7 2 
0 0 0 
Tlius the produce on Plot 2, manured with superphosphate 
alone, amounted to 13 tons 7^ cwts. per acre, whilst the addition 
of 2 cwts. of muriate of potash raised the crop to 15| tons 
calculated per acre. 
We have here an excellent example, showing how desirable it 
is to leave in all field trials 3 plots unmanured. Many anomalies 
which characterise some field experiments, I feel convinced, 
would frequently admit of a rational explanation if 3 plots, 
one at each end of the experimental field and one in the centre, 
were left unmanured ; for the produce of these unmanured plots 
would show at once whether the field was uniform or not, as 
regards its condition and actual productive powers. 
