Year. Bushels.
1844 15       
1845 23-1/4
1846 18       
1847 16-7/8
1848 14-3/4
1849 19-1/4
1850 15-7/8
1851 15-7/8
Average of 8 years 17-3/8

Table III.—(b.) Results of subsequent Forty Years (1852 to 1891).

  Grain Weight per Straw
  (bushels). bushel. (cwts.)
20 years (1852-1871) 14-1/2 57-5/8 13       
20 years (1872-1891) 11-1/2 58-3/4  8-5/8
40 years (1852-1891) 13        58-1/4 10-5/8
49th season (1891)  9-3/8 59-1/2  7-1/2

It is interesting to notice the comparatively slight decrease which has taken place in the yield of wheat during these fifty years. With such wide variations, due to season, it is extremely difficult, as Sir J. Henry Gilbert has pointed out, to estimate rate of decline due to exhaustion. Excluding the very bad seasons, this may be reckoned at from one-fourth to one-third of a bushel per acre per annum. The return of the first year is 15 bushels, while the yield of the forty-ninth season is 9-3/8 bushels. The average of the returns obtained during these fifty years is really in excess of the average yield of the principal wheat-producing countries in the world. This is truly a most astounding result.

The next experiments we shall describe are those on the influence of farmyard manure on the wheat crop when grown continuously.


TABLE IV.—Wheat grown continuously with Farmyard Manure (14 tons per annum).

    Weight per Straw
  Bushels. bushel (lb.) (cwts.)
  8 years (1844-1852) 28       — —
20 years (1852-1871) 35-7/8 60       33-7/8
20 years (1872-1891) 33-1/2 60-3/8 31-3/8
40 years (1852-1891) 34-7/8 60-1/4 32-5/8

It will be seen from the above results, which contain merely a selection from a very much greater number of experiments, that farmyard manure gives as good an average over the forty years as most of the artificial mixtures do. That this is due to the nitrogen it contains, is strikingly illustrated by the fact that mixed mineral manures alone give less than half the return, and also by the fact that ammonia salts alone give a return twice as great as mineral mixtures; while, lastly, the mixture of mineral manures and ammonia salts gives but a slight increase over that obtained with ammonia salts alone.

The remaining results, selected from a much larger number, need no comment, and we shall give them in tabular form.

Table V.—Wheat grown continuously with Artificial Manures, Farmyard Manure, and Unmanured.

Average of Forty Years (1852-91).

  Produce per Acre—Average per Annum.
  Dressed grain.
Manures per Acre per Annum. Quantity.
  20 years, 20 years, 40 years,
  1852-71. 1872-91. 1852-91.
  bush. bush. bush.
Farmyard manure, 14 tons per annum since 1843 35-7/8 33-1/2 34-7/8
Unmanured continuously 14-1/2 11-1/2 13      
Mixed mineral manures1 and 3-1/2 cwt. superphosphate 17       12-7/8 15      
Mixed mineral manures, 3-1/2 cwt. superphosphate, 200 lb. ammonium salts 26-1/2 21-3/4 24-1/8
Mixed mineral manures and 3-1/2 cwt. superphosphate, 600 lb. ammonium salts 38-1/4 34-3/4 36-1/2
Mixed mineral manures, 3-1/2 cwt. superphosphate, 275 lb. nitrate of soda 36-7/8 34       35-3/8
275 lb. nitrate of soda 26       19-3/8 22-3/4
400 lb. ammonium salts every year since 1845 22-1/2 19       22-1/2
400 lb. ammonium salts, 3-1/2 cwt. superphosphate 28       22-1/4 25-1/8
Mineral manure, 3-1/2 cwt. superphosphate, 400 lb. ammonium salts in autumn. 31-5/8 29-1/2 30-1/2
1By the term mixed mineral manures is meant a mixture of mineral fertilisers, not including phosphates.

TABLE V.—continued

  Produce per Acre—Average per Annum.
  Dressed grain.
Manures per Acre per Annum. Weight per bushel.
  20 years, 20 years, 40 years,
  1852-71. 1872-91. 1852-91.
  lb. lb. lb.
Farmyard manure, 14 tons per annum since 1843 60       60-3/8 60-1/4
Unmanured continuously 57-5/8 58-3/4 58-1/4
Mixed mineral manures and 3-1/2 cwt. superphosphate 58-7/8 59       58-7/8
Mixed mineral manures, 3-1/2 cwt. superphosphate, 200 lb. ammonium salts 59-3/8 60       59-5/8
Mixed mineral manures and 3-1/2 cwt. superphosphate, 600 lb. ammonium salts 59       60       59-1/2
Mixed mineral manures, 3-1/2 cwt. superphosphate, 275 lb. nitrate of soda 58-3/8 59-5/8 59      
275 lb. nitrate of soda 56-5/8 56-5/8 56-5/8
400 lb. ammonium salts every year since 1845 58       57-3/8 57-5/8
400 lb. ammonium salts, 3-1/2 cwt. superphosphate 57-3/8 58       57-5/8
Mineral manure, 3-1/2 cwt. superphosphate, 400 lb. ammonium salts in autumn 59-1/2 60       59-3/4

TABLE V.—continued

  Produce per Acre—Average per Annum.
   
Manures per Acre per Annum. Total straw.
  20 years, 20 years, 40 years,
  1852-71. 1872-91. 1852-91.
  cwt. cwt. cwt.
Farmyard manure, 14 tons per annum since 1843 33-7/8 31-3/8 32-5/8
Unmanured continuously 13       8-5/8 10-5/8
Mixed mineral manures and 3-1/2 cwt. superphosphate 15       9-3/4 12-3/8
Mixed mineral manures, 3-1/2 cwt. superphosphate, 200 lb. ammonium salts 24-1/2 19-1/8 21-7/8
Mixed mineral manures and 3-1/2 cwt. superphosphate, 600 lb. ammonium salts 41-3/8 39-5/8 40-1/2
Mixed mineral manures, 3-1/2 cwt. superphosphate, 275 lb. nitrate of soda 41-1/2 37-3/4 39-5/8
275 lb. nitrate of soda 28-1/4 18-1/2 23-3/8
400 lb. ammonium salts every year since 1845 24-3/4 16-1/4 20-1/2
400 lb. ammonium salts, 3-1/2 cwt. superphosphate 26-3/8 21       23-3/4
Mineral manure, 3-1/2 cwt. superphosphate, 400 lb. ammonium salts in autumn 31-1/4 28-3/8 29-3/4


TABLE VI.—Experiments on the Growth of Barley for Forty Years, 1852-91.

  Produce per Acre—Average per Annum.
  Dressed grain.
Manures per Acre per Annum. Quantity.
  20 years, 20 years, 40 years,
  1852-71. 1872-91. 1852-91.
  bush. bush. bush.
Unmanured continuously 20       25-1/2 16-1/2
3-1/2 cwt. superphosphate of lime 25-1/2 17-3/4 21-3/4
Mixed mineral manures 22-1/2 13-1/2 18      
Mixed mineral manures, 3-1/2 cwt. superphosphate 27-1/2 17-1/4 22-3/8
200 lb. ammonium salts 32-1/2 25-5/8 29      
200 lb. ammonium salts, 3-1/2 cwt. superphosphate 47       38-1/2 42-3/4
200lb. ammonium salts, mixed mineral manures 35       27-3/4 31-3/8
Manures, 3-1/2 cwt. superphosphate of lime 46-1/4 40-3/4 43-1/2
275 lb. nitrate of soda 37       28-3/8 32-3/4
275 lb. nitrate of soda, 3-1/2 cwt. superphosphate 49-1/4 42-1/4 45-3/4
275 lb. nitrate of soda, mixed mineral manures 37-3/8 29-1/2 33-1/2
275 lb. nitrate of soda, mixed mineral manures, 3-1/2 cwt. superphosphate 49-3/4 41-1/4 45-1/2
1000 lb. rape-cake 45-1/4 37-1/8 41-1/4
1000 lb. rape-cake, 3-1/2 cwt. superphosphate 46-3/4 40       43-3/8
1000 lb. rape-cake, mixed mineral manures 43-5/8 35-5/8 39-1/2
1000 lb. rape-cake, mixed mineral manures, and 3-1/2 cwt. superphosphate 47-3/8 39       43-1/4
Farmyard manure, 14 tons every year 48-1/4 49       48-5/8

TABLE VI.—continued

  Produce per Acre—Average per Annum.
  Dressed grain.
Manures per Acre per Annum. Weight per bushel.
  20 years, 20 years, 40 years,
  1852-71. 1872-91. 1852-91.
  lb. lb. lb.
Unmanured continuously 52-3/8 51-3/4 52      
3-1/2 cwt. superphosphate of lime 53-1/4 53       53-1/8
Mixed mineral manures 53       51-7/8 52-1/2
Mixed mineral manures, 3-1/ cwt. superphosphate 53-3/8 52-3/8 53      
200 lb. ammonium salts 52-1/8 52       52      
200 lb. ammonium salts, 3-1/2 cwt. superphosphate 53-3/8 52-1/4 52-7/8
200 lb. ammonium salts, mixed mineral manures 52-3/4 52-1/2 52-5/8
Manures, 3-1/2 cwt. superphosphate of lime 54       54-1/8 54      
275 lb. nitrate of soda 52       52-1/8 52      
275 lb. nitrate of soda, 3-1/2 cwt. superphosphate 53-3/8 53-1/4 53-1/4
275 lb. nitrate of soda, mixed mineral manures 52-1/4 52-3/4 52-1/2
275 lb. nitrate of soda, mixed mineral manures, 3-1/2 cwt. superphosphate 53-3/8 54       53-5/8
1000 lb. rape-cake 53-3/4 53-7/8 53-7/8
1000 lb. rape-cake, 3-1/2 cwt. superphosphate 53-7/8 54-3/8 54-1/8
1000 lb. rape-cake, mixed mineral manures 53-3/4 54-1/8 54      
1000 lb. rape-cake, mixed mineral manures, and 3-1/2 cwt. superphosphate 53-5/8 54-1/4 53-7/8
Farmyard manure, 14 tons every year 54-3/8 54-1/4 54-1/4

TABLE VI.—continued

  Produce per Acre—Average per Annum.
   
Manures per Acre per Annum. Total straw.
  20 years, 20 years, 40 years,
  1852-71. 1872-91. 1852-91.
  cwt. cwt. cwt.
Unmanured continuously 11-3/4   6-7/8   9-3/8
3-1/2 cwt. superphosphate of lime 13-3/8   8-1/4 10-3/4
Mixed mineral manures 12-1/4 7       9-5/8
Mixed mineral manures, 3-1/2 cwt. superphosphate 14-3/8   8-3/8 11-3/8
200 lb. ammonium salts 18-1/2 13-1/2 16      
200 lb. ammonium salts, 3-1/2 cwt. superphosphate 27-5/8 20-1/8 23-7/8
200 lb. ammonium salts, mixed mineral manures 20-1/4 15-1/8 18      
Manures, 3-1/2 cwt. superphosphate of lime 28-1/2 23-3/8 25-7/8
275 lb. nitrate of soda 22-1/8 15-7/8 19      
275 lb. nitrate of soda, 3-1/2 cwt. superphosphate 30-1/2 23-3/8 27      
275 lb. nitrate of soda, mixed mineral manures 23-7/8 17-1/2 20-3/4
275 lb. nitrate of soda, mixed mineral manures, 3-1/2 cwt. superphosphate 32-3/8 24-1/2 28-1/2
1000 lb. rape-cake 26-7/8 20       23-3/8
1000 lb. rape-cake, 3-1/2 cwt. superphosphate 28-3/8 21-1/2 24-7/8
1000 lb. rape-cake, mixed mineral manures 27-1/8 19-7/8 23-1/2
1000 lb. rape-cake, mixed mineral manures, and 3-1/2 cwt. superphosphate 29-3/4 21-7/8 25-5/8
Farmyard manure, 14 tons every year 28-1/4 29-3/4 29      

TABLE VII.

Experiments on the Growth of Oats, 1869-78.

  Average per Annum.
5 years, 1869-73.
  Dressed grain.  
Manures per Acre per Annum.   Weight Total
  Quantity. per bushel. straw.
  bush. lb. cwt.
Unmanured 19-7/8 33-3/4 10-3/8
200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and 3-1/2 cwt. superphosphate of lime 24-1/2 35       13-3/8
400 lb. ammonium salts 47       35-7/8 28-1/2
400 lb. ammonium salts, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and 3-1/2 cwt. superphosphate 59       37       41-1/8
550 lb. nitrate of soda 47-1/8 35-1/2 27-1/2
550 lb. nitrate of soda, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and 3-1/2 cwt. superphosphate 57-1/2 35-3/4 35      
  Average per Annum.
4 years, 1874-78.
  Bushels. lb. cwt.
Unmanured 13-3/4 31-1/4 6    
200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and 3-1/2 cwt. superphosphate of lime 13-1/8 31-5/8   6-1/8
200 lb. ammonium salts 28-7/8 33-1/4 14-1/8
200 lb. ammonium salts, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and 3-1/2 cwt. superphosphate 38       35-1/2 20      
275 lb. nitrate of soda 26-3/8 31-5/8 11-1/8
275 lb. nitrate of soda, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and 3-1/2 cwt. superphosphate 28-1/2 34-1/8 14      

TABLE VIII.—Experiments on Root Crops: Swedish Turnips.

Fifteen Seasons, 1856-70.1 Roots and Leaves carted off the Land.

    Series 1.
     
    Standard manures
    only.
     
     
     
     
  STANDARD MANURES.  
     
Plots.    
  Roots. Leaves.
    Tons. cwt. Tons. cwt.
  1 Farmyard manure, 14 tons   6   4   0 17
  2 Farmyard manure, 14 tons, and superphosphate   6   7   0 16
           
  3 Without manure, 1846, and since   0 11   0   3
  4 Superphosphate, each year; sulphate potash, soda, and magnesia, 1856-60   2 16   0   8
  5 Superphosphate, each year   2 12   0   9
  6 Superphosphate, each year; sulphate potash, 1856-60   2   7   0   7
  7 Superphosphate, each year; sulphate, potash, and 36-1/2 lb. ammonium salts, 1856-60   2 12   0   7
           
  8 Unmanured 1853, and since; previously part unmanured; part superphosphate   1   3   0   4
Note.—Sulphate of ammonia is estimated to contain 23 per cent ammonia, and muriate of ammonia 27 per cent. Ammonium salts, in each case, equal parts sulphate and muriate of ammonia of commerce; and the mixture is estimated to contain 25 per cent ammonia. The 328 lb. nitric acid (sp. gr. 1.35) mixed with sawdust, and used as a cross-dressing on the plots of Series 2 from 1856-60, were estimated to contain nitrogen = 50 lb. ammonia.
 
1The crops of 1859 and 1860 failed, and were ploughed in; but as the manures were applied, and there would be accumulation with the soil for the succeeding crops, the average produce is calculated as for fifteen years—that is, the produce of the thirteen years is, in each case, divided by 15.

TABLE VIII.—continued

    Series 2. Series 3.
       
    Standard manures, Standard manures,
    and cross-dressed with— and cross-dressed with—
    5 years, 1856-60, 5 years, 1856-60,
    3000 lb. sawdust, and 200 lb. ammonium
    328 lb. nitric acid. salts.
   
  STANDARD MANURES. 10 years, 1861-70, 10 years, 1861-70,
    550 lb. nitrate soda. 400 lb. ammonium salts.
Plots.      
  Roots. Leaves. Roots. Leaves.
    Tons. cwt. Tons. cwt. Tons. cwt. Tons. cwt.
1 Farmyard manure, 14 tons   7   9   1   2   8   8   1   4
2 Farmyard manure, 14 tons, and superphosphate   7 13   1   3   8   5   1   5
3 Without manure, 1846, and since   0 19   0   4   0 13   0 3
4 Superphosphate, each year; sulphate potash, soda, and magnesia, 1856-60   5 2   0 16   4 12   0 14
5 Superphosphate, each year   4 13   0 18   3 16   0 15
6 Superphosphate, each year; sulphate potash, 1856-60   4 11   0 14   4   5   0 13
7 Superphosphate, each year; sulphate, potash, and 36-1/2 lb. ammonium salts, 1856-60   4 13   0 14   4 12   0 14
8 Unmanured 1853, and since; previously part unmanured; part superphosphate   1 13   0   5   1   2   0   5

TABLE VIII.—continued

    Series 4. Series 5.
       
    Standard manures, Standard manures,
    and cross-dressed with— and cross-dressed with—
    5 years, 1856-60, 5 years, 1856-60,
    200 lb. ammonium salts, 3000 lb. sawdust.
    and 3000 lb. sawdust.  
   
  STANDARD MANURES. 10 years, 1861-70, 10 years, 1861-70,
    400 lb. ammonium salts, 2000 lb. rape-cake.
Plots.   and 2000 .b. rape-cake.  
  Roots. Leaves. Roots. Leaves.
    Tons. cwt. Tons. cwt. Tons. cwt. Tons. cwt.
1 Farmyard manure, 14 tons   8 16   1   9   8   0   1   4
2 Farmyard manure, 14 tons, and superphosphate   8 14   1   9   7 16   1 2
3 Without manure, 1846, and since   3   6   0 14   3   8   0 13
4 Superphosphate, each year; sulphate potash, soda, and magnesia, 1856-60   6 12   1   5   5   8   0 17
5 Superphosphate, each year   5 16   1   7   5   0   0 19
6 Superphosphate, each year; sulphate potash, 1856-60   6   6   1   2   5   3   0 16
7 Superphosphate, each year; sulphate, potash, and 36-1/2 lb. ammonium salts, 1856-60   6 15   1   4   5   9   0 17
8 Unmanured 1853, and since; previously part unmanured; part superphosphate   3 19   0 18   3 14   0 19

TABLE IX.—Experiments on Mangel-Wurzel.

Average of Sixteen Seasons, 1876-92. Manures per Acre per Annum.

    Series 1.
     
  STANDARD MANURES. Standard manures
    only.
     
Plots.    
  Roots. Leaves.
    Tons. cwt. Tons. cwt.
1 Farmyard manure, 14 tons 16   6   2 17
2 Farmyard manure, 14 tons, and 3-1/2 cwt. superphosphate   4   9   1   8
           
3 Without manure, 1846, and since   4   9   1   8
4 3-1/2 cwt. superphosphate, 500 lb. sulphate of potash and 400 lb. mixed mineral manure   5   8   1   1
           
5 3-1/2 cwt. superphosphate   5   0   1   1
6 3-1/2 cwt. superphosphate, and 500 lb. sulphate of potash   4   9   0 18
           
7 3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 36-1/2 lb. ammonium salts   5 17   1   8