3GG Field JExjyeriments at Woburn in 1889 and 1890. 
about two bushels increase and considerably more straw. Doubling 
the dressing of nitrate of soda gave only 4 bushels more in 1889, 
and 2 bushels extra in 1890. Rather more relative increase was 
obtained from doubling the ammonia-salts, but nitrate of soda gave 
the higher total yields. The omission of the top-dressing for a 
single year did not in either season give such marked distinctions 
as heretofore, between ammonia-salts and nitrate of soda, when 
severally omitted. Thus in 1889 when ammonia-salts were left out 
the yield fell to 21 '9 bushels and to 18 bushels when nitrate of soda 
was not put on ; but in 1890 the crop grown on the residue of the 
nitrate of the former year was even higher than that from the 
ammonia-salts. It is only fair, however, to mention that in this 
year plot 8a was very patchy indeed. Plot 2 as usual looked at 
first extremely bare in parts. In 1889 neither farmyard manure nor 
rape cake applied as top-dressings told well, and in 1890 the effect 
of the rape cake was not nearly so marked — when compared with 
the farmyard manure— as in the case of the wlieat crop. 
B. The Rotation Experiments. 
These experiments were designed to ascertain, in brief, whether 
the difference between the high manurial value of decorticated cotton- 
cake when consumed on the land, as compared with the lower one 
of maize-meal, is brought out in the respective crops grown by the 
use of each, and also if the same difference is shown when artificial 
manures of estimated equivalent strength to decorticated cotton- 
cake and maize-meal severally are used. 
The original plan of experiment was to manure for the root-crop 
with dung made by the consumption of decorticated cotton-cake 
and maize-meal respectively, then to feed off the roots on the land, 
following with barley, and after that clover, which latter was eaten 
off with decorticated cotton-cake and maize-meal once more, in 
preparation for the wheat crop. After following this plan for two 
entire four-course rotations, viz. 1877-81, it was found that the 
expected difference was not shown, but that full crops had been 
produced by the poorer manuring. The plan was accordingly 
altered, and the field divided into two halves, tl>e crops on one half 
being grown without any manure, and being successively removed 
Year 
Kotation, No. T. 
4 acres 
Rotation, No. 2. 
4 acres 
Rotation, No. 3. 
4 acres 
Rotation, No. 4. 
4 acres 
188.5 
Seeds 
Roots 
1886 
Wheat 
Barley 
Seeds 
Hoots 
1887 
Hoots 
Seeds 
Wheat 
Barley 
1888 
Barley- 
Wheat 
Roots 
Seeds 
1881) 
Seeds 
Hoots 
Barley 
Wheat 
1890 
Wheat 
Barley 
Seeds 
Hoots 
off the land with the idea of removing its accumulated over-fertility, 
while on the other half numuring with decorticated cotton-cake and 
