14 



labelled pH, and the lower they are the greater the degree of 

 acidity. Thus the following Garforth soils have been tested : — 



pH value 

 Very acid, wheat bad ..... 4.37 

 Less acid, wheat poor ..... 4.44 

 Still less acid, wheat better . . . .4.65 



Still less acid, wheat good .... 4.82 



Another set gave these results : — 



Acid, finger and toe prevalent on turnips . 5.64 

 Less acid, no finger and toe . . . .6.13 



It is also shown that there is a closer relationship between the 

 pH values and the Hutchinson-McLennan "Lime requirement" 

 values than might have been expected, and the latter afford useful 

 guidance in placing similar soils in order of acidity. 



THE FEEDING OF THE PLANT. 



Farmers are now thoroughly familiar with the fact that the 

 production of heavy crops necessitates a skilful and adequate use 

 of fertilisers. In spite of the severe agricultural depression of the 

 past two years, there has been a considerable consumption of 

 fertilisers : in some cases greater than in pre-war times ; this is 

 shown in the foUow^ing table : — 



AVAILABLE SUPPLIES OF FERTILISERS IN TONS: GREAT BRITAIN 

 AND IRELAND. (1) 



(1) Min. Ag. Statistics, 1921, Vol. LVI, p. 107 and private communication. No information 

 is available as to actual consumption on farms or as to stocks carried over from one 

 year to another. 



Net imports for all purposes. 



+ Ignoring imports and exports. 



Artificial manures influence not only the amount but also the 

 character of the plant growth, and very often the quality of the 

 produce. So long as farmers were confined mainly to farmyard 

 manure they could and did discover for themselves its effects on 

 the crop. But there are now more than thirty manures available 

 for the farmer, and an ingenious chemist could make up over 6,000 

 different recipes for the potato crop alone, to say nothing of the 

 mixtures required for other crops on the farm ; and to add to the 

 complexity of the matter no manure acts in quite the same way on 

 two different farms, while even on the same farm the effect may 

 vary considerably from season to season. Hence the need for 

 experimental work to discover the general rules by which to guide 

 farmers as to the most suitable of the possible mixtures. 



