EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT MEADOW. 325 
other mineral constituents, and a little nitrogen, but all presumably in an only slowly 
available condition. 
Table X.—Average, per acre per annum, by 400 lbs. Ammonia-Salts, with Mixed 
Mineral Manure containing Potass, and 2000 lbs. cut Wheat Straw ; Plot 13. 
Average per acre per annum. 
Plot 9. 
Mineral manure 
and 400 lbs. 
ammonia-salts. 
Plot 13. 
As plot 9, 
and 2000 lbs. 
cut wheat-straw. 
Plot 13 
+ or — 
plot 9. 
Hay. 
lbs. 
lbs. 
lbs. 
First period, 10 years, 1856-1865 . 
6002 
6186 
+ 184 
Second period, 10 years, 1866-1875. 
5421 
6679 
+ 1258 
Total period, 20 years, 1856-1875 . 
5711 
64.32 
+ 721 
Second period, per cent. + or — first period . . . 
- 9-7 
+ 8-0 
i . 
Nitrogen. 
First period, 10 years, 1856-1865 . 
757 
79-5 
+ 3-8 
Second period, 10 years, 1866-1875 . 
70-7 
87-3 
+ 16-6 
Total period, 20 years, 1856-1875 . 
73-2 
83-4 
+ 10-2 
Second period, per cent. + or — first period . . . 
— 6-6 
+ 9-8 
Mineral Matter (Ash). 
First period, 10 years, 1856-1865 . 
368-3 
389-2 
+ 20-9 
Second period, 10 years, 1866-1875 . 
301-0 
382-8 
+ 81-8 
Total period, 20 years, 1856-1875 . 
334-6 
386-0 
+ 51-4 
Second period, per cent. + or — first period . . . 
-18-3 
-1-6 
There is here considerably more average produce of hay, and more of nitrogen and 
mineral matter removed, over the 20 years, than by the same manures without the straw. 
There is also, instead of a reduction, a considerable increase, in the yield of hay and of 
nitrogen, and a nearly equal yield of mineral matter, over the second 10 years compared 
with the first. 
The exact explanation of the much greater productiveness where the cut straw was 
used is not very obvious, but it may be well be enumerate some of the coincidents of 
this result. 
Plot 13, like plot 12, the duplicate unmanured plot, is earlier shaded from the after¬ 
noon sun than the remaining plots, and plot 12 gave, every year of the 20, excepting 
the first two and the twelfth, more produce than the other unmanured plot (3). Plot 13 
again, though it gave less produce than plot 9 during the first three years, has, with 
