EXPERIMENTAL STATIONS — BARLEY CROP, 1887. 221 



was cropped without manure in 1879 and in 1880, the crops 

 removed being respectively barley and ryegrass, so that the 

 steady manuring of the field may be said to have begun in 

 1881, when a crop of oats was grown succeeded by turnips and 

 barley. Again, in 1884, a crop of oats was grown without 

 manures, but in 1885 manures were applied, and another crop 

 of oats removed. In 1886 and 1887, as mentioned above, there 

 were removed from one half of the station a crop of potatoes 

 and a crop of barley that had not been manured. In looking 

 for the unexhausted residues we have, therefore, to keep in view 

 that the manures we are looking for were applied only in the 

 years 1881, 1882, 1883, and 1885. The reason for withholding 

 manures in 1884 was that the field was in too high condition 

 to show the effects of light manures in a marked manner. 

 Considering that the field is a fertile one, and that the manures 

 were applied so many years agO; any considerable residue is 

 not to be expected. Nevertheless, as will be seen from the 

 results contained in Table III., the traces of former manuring 

 are distinctly visible. It is impossible to say what proportion 

 of the residual fertility is due to recent and what to more 

 remote manuring. The estimation of residual fertility was no 

 part of the original experiments, and they were not specially 

 arranged to yield information on that subject. 



A clear and rapid view of the comparative fertility of the 

 various plots may be had from a glance at diagram YI., on 

 which the produce of the manured and unmanured half of each 

 plot is compared. We shall first consider the crop upon the 

 unmanured half. 



Unmanured Section. 



The unbroken line on the diagram indicates the produce of 

 this section. 



As regards the phosphate plots, it will be seen that 

 plot 3 (ground coprolites) shows an unexpected superiority, 

 and in this respect it stands in marked contrast to the 

 corresponding plot at Pumpherston. In former years it 

 had not shown any superiority, but was always inferior to 

 plot 4, and in the previous year the residue on that plot did 

 very little for the potato crop. From notes taken during 

 repeated visits while the crop was growing, there was no 

 appearance of any superiority until towards the time of ripen- 

 ing. It was somewhat later of ripening, and it was considered 

 that the soil at that part of the field was a little damper than 

 average. In such a dry early season as 1887 that would 

 give it a great advantage. The same remark applies to plots 

 12 and 13, which are near the boundary of the field, and in 

 close proximity to a ditch which was filled up a good many 



