for Twenty Years in succession on the same Land. 353 
is given the produce of bailey in 1853, 1854, and 1855, on plots 
manured for the turnips as under : — 
1. A series of plots having various purely mineral manures 
during the last 8 of the 10 years of the turnips. 
2. Plots having the same mineral manures as j., during the 
last 8 years, and ammonia-salts (an average of 45 lbs, of nitrogen 
per acre per annum) during the first 6 of the last 8 years, namely 
1845-1850 inclusive. 
3. Plots having the same mineral manures during the last 8 
years as 1 and 2, and, in addition, an average of nearly 17 cwts. 
rape-cake ( = 90 lbs. nitrogen) per acre, per annum, during the 
first 6 of the last 8 years. 
4. Plots having the same mineral manures as 1, 2, and 3, 
during the last 8 years, and both the ammonia-salts (=45 lbs. 
nitrogen), and the rape-cake (=90 lbs. nitrogen), per acre, per 
annum, during the first 6 of the last 8 years. 
There is also given in the Table the produce of barley in 
1854 and 1855, on— 
5. A portion of the previously mineral-manured turnip-land, 
dressed for the barley-crop of 1854 with ammonia-salts, at the 
rate of 400 lbs. per acre (= 82 lbs. nitrogen) ; but without further 
manure in 1855. 
6. Another portion of the previously mineral-manured turnip- 
land, dressed with nitrate of soda, at the rate of 550 lbs. per acre 
(= 82 lbs. of nitrogen), for the barley-crop of 1854, and of 
ll2 lbs. (=17 lbs. of nitrogen), for the crop of 1855. 
The average produce of turnips over the last 8 years (1845— 
1852) was :— 
1. 
With Mineral 
Manure, 
alone. 
2. 
Witli Mineral 
Manure, 
and 
Ammonia-salts. 
3. 
With Mineral 
Manure, 
and 
Rape-cake. 
4. 
With Mineral 
Manure, 
Ammonia-talts, 
and 
Rape-cake. 
Tons. Cwts. 
7 9 
1 loi 
Tons. Cwts. 
10 4| 
3 3 
Tons. Cwts. 
10 191 
2 13^ 
Tons. Cwts. 
12 31 
4 7i 
Total .. .. 
8 195 
13 71 
13 121 
16 111 
Thus, with purely mineral manures the produce was but small ; 
with mineral manure and ammonia-salts it was more ; with 
mineral manure and rape-cake again rather more ; and with 
mineral manure, ammonia-salts, and rape-cake, together, it 
was the heaviest, but still, on the average, only about 124- tons 
of roots, and 44 tons of leaves, per acre per annum. On some 
portions the mineral manures supplied more of all the mineral 
constituents than were removed in the turnip-crops, but on others 
