222 CHEMICAL DEPARTMENT. 



years ago when the march there was being rectified. In other 

 respects the appearance of these plots, and plots 7, 8, 9, and 

 10 resemble the corresponding plots at Pumpherston. The 

 differences are of course not so marked for reasons already 

 explained, and for the further most important reason that the 

 extreme drought and earliness of the harvest did not give 

 a good opportunity for residual fertility showing itself 



Among the nitrogenous manures the horn dust plot (15) and 

 the dried Mood plot (16) are, as at Pumpherston, the best, but 

 the rapecake dust (35) has not done so much for the plot as at 

 Pumpherston. 



Of the two potash manures the sulphate (19) has left a little 

 more residue than the muriate (20), but its superiority is not 

 so decided as at the other station. The former year, when 

 potatoes were grown on these plots; the residue left by the 

 muriate was far more effective than that left by the sulphate, 

 the crop on the former being about half as much again. It is, 

 therefore, to be expected, though it does not necessarily follow, 

 that the muriate plot would thus be in a more exhausted con- 

 dition. Plot 21, which has never had any potash manures 

 applied to it, produced little more than half as much potatoes 

 as the other plots of this group, and we therefore find, as we 

 should expect, that there is a larger manurial residue left in it 

 for the barley crop. Apart from that circumstance, however, 

 it has been observed at both stations that the want of potash 

 is not much felt by the barley crop, while the plot which had a 

 double dose of muriate of potash (34) suffered much from the 

 application, and the plot which had nothing but potash salts 

 applied to it (22) produced in former years at Harelaw one of 

 the worst crops of barley, and at Pumpherston the very worst 

 on the station, on both occasions when barley was grown. 



There is little to be noted regarding the after effects of the 

 different guanos. The greatest residue has been left by Peruvian 

 guano (23) on both stations, and during the former years it 

 bore larger crops than the others of the series ; but it will be 

 seen that the guano plots as a whole have produced rather 

 poor crops. 



The superphosphate plots 28, 29, and 30 are a distinct experi- 

 ment ; they were not entirely unmanured. The half plots that 

 should have been unmanured had one substance applied to 

 them, viz., nitrate of soda in equal quantity with the manured 

 half The result of that application is the production of a very 

 great increase of barley, and the increase is greater according as 

 the superphosphate was the more soluble. 



The very small crop grown on plot 31 requires some explana- 

 tion. The great deficiency there is not attributable to the 

 manurial treatment. It was noticed, in observations made 



