502 Summary of Agricultural Experiments, [sept., 



menting the ordinary dressing of dung with a moderate application of 

 a well-balanced mixture of artificial manure. The commonest practice 

 in the south-eastern counties of Scotland is to grow potatoes after a 

 corn crop, and by way of preparation to apply 15 or 20 tons of high- 

 class farmyard manure, either on the stubble or in the drill in the 

 spring. 



Four plots were laid down at six centres, all being manured alike 

 with farmyard manure. The effect of a dressing of 1^ cwt. sulphate of 

 ammonia, 4 cwt. superphosphate, and cwt. sulphate of potash per 

 acre was tested on one plot, and a dressing of half this quantity on 

 another plot at each centre. The full dressing cost a little over £2 per 

 acre, and produced an average increase of 3 tons 12 cwt. per acre; 

 while the half-dressing increased the crop on the average by 2 tons 

 5 cwt. per acre, and cost £1 is. 6d. 



Another mixture was also tested with similar results, and there 

 appears little doubt that it pays in most cases to supplement farmyard 

 manure with a complete mixture of artificials. 



Liming of Arable Land (West of Scot. Agric. Coll., Bull. 55). — The 

 effect of the application of lime in large amounts at long intervals of 

 time has been compared with the effect of small and frequent dressings. 

 The experiment was carried out from 1902 to 1909 on a light, loamy 

 soil poor in lime, but in excellent physical condition. Four plots of 

 £^ acre each in size were treated with 4 tons of lime per acre, applied 

 in one, two, four, and eight dressings of 4 tons, 2 tons, 1 ton, and 

 \ ton respectively, the first dressing being given in the winter of 1901-2, 

 and the subsequent dressings, if any, in each succeeding winter. In 

 addition, one plot was treated with 5 cwt. lime in each of the eight 

 years, and the effect of the application of 4 tons gas lime in one amount 

 was tested on another plot. The rotation during the eight years was 

 as follows : Turnips, barley, seeds hay, oats, potatoes, wheat, seeds hay, 

 and oats. 



The conclusions drawn from this experiment may be summarised as 

 follows : — 



Large dressings of not less than 4 tons per acre applied at long 

 intervals of time are much less effective in producing an increased yield 

 of crops than the same quantity of lime applied more frequently in 

 divided doses, and on such soils as that on which these experiments 

 were conducted they are not likely to prove profitable. The largest 

 increases were obtained in this experiment from annual applications of 

 10 cwt. burnt lime per acre. Applications of 5 and of 10 cwt. per acre 

 per annum gave profitable results, but the larger dressings of 1, 2, and 

 4 tons per acre proved very unprofitable. 



The direct application of lime to the turnip crop produced a large 

 increase in the yield, and the larger the quantity of lime given, up to 

 4 tons per acre, the greater was the increase. A dressing of 10 cwt. 

 per acre proved, however, most profitable. 



On the hay crop lime applied to the previous crops was beneficial, 

 but lime applied on the young seeds tended to diminish the yield of 

 hay, except when given in small quantity. Liming exercised a bene- 

 ficial effect on all the cereal crops, but on the potato crop the effect of 

 liming was invariably injurious. 



Gas lime applied at the rate of 4 tons per acre to the turnip crop 



