Experimental Crops at Rothamsted. 
125 
of the barley by scarcely two-fifths, and in that of the wheat by 
only about one-sixth, compared with average amounts. 
For the hay-crop, farmyard manure was only applied during 
the first 8 years of the 15 ; but as the average produce was as 
ijreat over the succeeding 6 years without the manure, as over 
the first 8 years with it, and as tliere was a heavier crop in 1869 
than in any of the preceding 18 years, the deficiency in 1870 
compared with the average, may be taken as at any rate mainly 
due to the drought, and but little to the cessation of the 
manuring. The figures as they stand show, as without manure, 
again, a much greater deficiency than in either wheat or barley ; 
tlie crop amounting in fact to only one-third the average. Of 
total produce of wheat and barley, there is, with farmyard 
manure, again nearly the same average amount over 19 years 
in the two cases. The deficiency in 1870 compared with the 
average is also very nearly the same with the autumn-sown 
wheat and the spring-sown barley ; amounting in each case 
to scarcely one-sixth. In the wheat the reduction is actually 
much greater, but in proportion to the average, only about the 
same as without manure ; but in the barley it is actually less, 
though in proportion to the average very much less, than without 
manure. The greater power of retention of water which a dunged 
soil has been shown to possess in its upper layers, has doubtless 
much to do with the result. 
With the artificial mixture in the case of the hay and the 
wheat supplying 400 lbs., but in that of the barley only 200 lbs. 
of ammonia-salts per acre per annum, there is not the same 
uniformity in the average annual produce of the three crops ; 
the wheat giving nearly 500 lbs. more gross produce than the 
hay with the same amount of ammonia applied, and the barley 
about the same as the hay, with only half the supply of ammonia- 
salts. The deficiency in 1870 amounts, in the hay to more than 
two-fifths, in the barley to rather more than one-fourth, and in the 
wheat to little more than one-fifteenth, compared with the average. 
Thus, then, with a drought extending over the months of 
April, May, June, and July, the mixed herbage of permanent 
1 meadow land suffered, under the different conditions of manure 
j in question, very much more than either wheat or barley ; and 
' the spring-sown barley suffered, both without manure and with 
the artificial manure, very much more than the autumn-sown 
wheat. With the farmyard manure, however, the barley would 
appear to have been as little' adversely affected by the deficiency 
of rain during the period of actual growth as the wheat. We 
need not here again refer to the special conditions already ex- 
plained, under which the hay crop was as little, or less, affected 
by the drought than the other crops. 
