Effect of Farmyard Manure. 191 



received farmyard manure alone for eight years, 1856-63, 

 and then remained unmanured for twelve years, 1864-75 ; 

 whilst plot 1 received farmyard manure and ammonia-salts 

 for eight years, 1856-63, and ammonia-salts only for twelve 

 years, 1864-75. 



It is remarkable that, over the first six years of the 

 cessation of the application of the manure, the average pro- 

 duce was almost exactly the same as, and even rather more 

 than, during the application 48461b. against 48041b. ; and 

 the average annual increase was almost identical 21471 b. 

 against 21391b. Though one or two of the six years were 

 very productive seasons, the result is still very striking. 

 The next six years were rather the reverse in this respect, 

 and this, with the fact that the then remaining residue 

 would doubtless be in a less readily available condition, led 

 to there being little more than half as much average produce, 

 and less than two-fifths as much average increase, as over 

 the first six years of the action of the inanurial residue. 



The figures show that very much more nitrogen was 

 removed in the crops during the first than during the second 

 six years of the action of the residue. Moreover, the 

 amount of nitrogen taken up per acre per annum over the 

 first six years was less than during the eight years of 

 manuring. The reverse was the case with the yield of hay. 



Of mineral matter, there was twice as much removed in 

 the first as in the second six years of the action of the 

 residue ; and there was of it a greater falling off in the first 

 six years, compared with the years of the application, than 

 of either the hay or the nitrogen. 



The effect of the farmyard manure was to reduce the 

 number of species, to bring into greater prominence the 

 gramineous and miscellaneous herbage, but to reduce the 

 leguminous. The gramineous species became fewer. Poa 

 trivialis, Bromus mollis, and Avena flavescens were the 

 most prominent, whereas, without manure, not one of these 

 made much show, Festuca ovina, Agrostis vulgaris, Avena 



