REPORTS OF EXPERIMENTS WITH DIFFERENT TOP-DRESSINGS. 79 



Of the two chloride of ammonium in solution plots, one was 

 poor while the other was good. 



Plots 18, 21, 12, 35, were slightly spoilt by the hay cock of 

 the first crop lying on them too long. They were, therefore, not 

 considered at all in taking the average. 



The results of the second crop are not so satisfactory as those 

 of the first. The crops on the individual plots in each set vary 

 more in weight, and their weights do not bear any definite rela- 

 tion to those of the first crop. This seems unaccountable, but 

 there was the same extraordinary irregularity of second crop 

 all over the field. There were strong, patches of clover, and then, 

 nearly bare places, scattered over the field. It did not appear 

 that the best first crop was followed by either the best or worst 

 second crop, or that the worst first gave the best second. There 

 might have been a difference in the results, and a greater re- 

 gularity, had the second crop been cut sooner, for on some of the 

 plots the crop was over ripe at the time of cutting, and would 

 thus have lost in weight considerably. 



There is no doubt that the Peruvian guano — probably owing 

 to the other salts which it contains beside the ammonia salt — is 

 the most lasting in its effects, as it has produced far the best 

 second crop. 



The glue has had rather less effect on the first crop than the 

 salts, but has had more on the second crop than any, except the 

 Peruvian'guano. This would indicate that it is not decomposed 

 very rapidly, but requires some short time before it becomes avail- 

 able for the plant. 



The mixture of nitrate of soda with sulphate of ammonia has 

 slightly improved the second crop, instead of having diminished 

 it, as the other ammonia salts and nitrates have done. This is 

 satisfactory, as it is a usual top dressing in East Lothian. 



The slight beneficial, and in some cases even hurtful, effect of 

 some of the dressings on the second crop, may be owing to their 

 having stimulated the early growth at the ultimate expense of 

 the vigour of the clover plant, the grass being very equal on all 

 as far as one could judge. The second crop of clover on the 

 nothing plots being more, even, than that on any of the other 

 plots, it would seem that all the dressings had injured the clover 

 plant more or less, but that the Peruvian guano, glue, and nitrate 

 of soda with sulphate of ammonia, have been able, by stimulating 

 the remaining plants of clover, and more especially the grass, to 

 make up for the fewer clover plants. Whether it is that the 

 plant is quite used out, or that, having been stimulated once, it 

 requires the stimulant to be kept up, might be tested, by applying 

 a second dressing, — applying, at the same time, the same dressing 

 to plots which have received nothing the first crop. This expe- 



