844 



Liming. 



[July, 



(1) High cost of fuel, especially in the case of limestone 

 quarries situated away from coal areas. 



(2) In districts where limestone is used for road repairs, 

 definite testimony has been borne to its value by farmers who, 

 recognising the superiority of that kind of road scrapings and 

 ditch cleanings, have made a practice of using them. 



(3) It is possible to secure much finer grinding than was 

 practicable 15 or 20 years ago. 



(4) During recent years laboratory methods for ascertaining 

 the lime requirements of soils have been much improved. 

 Now it is possible to give the farmer reliable guidance in this 

 connection, so that he may know the minimum quantity of 

 limestone needed to meet the requirements of his particular 

 soil. 



(5) In the case of soils with low lime requirement it is 

 easier to apply small dressings of ground limestone than of 

 lump lime. 



Last year the writer conducted a pot experiment to ascertain 

 the influence of degree of fineness upon the efficiency of ground 

 limestone. Trefoil {Medicago luvulina) was chosen as the crop 

 to be grown, because Wales is mainly a grassland country, and 

 because the success of grassland farming is to be measured 

 largely by the farmer's success in keeping up a high proportion 

 of leguminous plants in the herbage. Further, Professor Lloyd 

 Williams furnished the information that, under Welsh conditions 

 of soil and climate, of the leguminous lime -loving plants, trefoil 

 was particularly sensitive to the action of lime. 



The carboniferous limestone chosen for the experiment was 

 analysed and found to contain : — 



Percentage. 



Moisture -23 



Calcium Carbonate ... ... ... ... 97'16 



Magnesium Carbonate ... ... ... "59 



Iron and Ahiminium oxides ... ... '25 



Matter insoluble in acid ... ... ... 1'32 



The soil used in the pots was fairly typical of the sedentary 

 soils on the Ordovician formation in Mid Wales. The soil was 

 found to be acidic in its action upon litmus paper. Its lime- 

 requirement, ascertained by shaking with a standard solution of 

 calcium bicarbonate, was found to be equivalent to 1.25 per 

 cent, of calcium carbonate (approximately equal* to 25 cwt. per 

 acre). Its mechanical and chemical composition is indicated in 

 the subjoined table : — 



