CH. iv] MANURING OF POTATOES 39 



In the Glasgow experiments 1 a mixture of basic slag and 

 superphosphate (3 cwts of each) was better than superphosphate 

 alone ; at Holmes Chapel 2 steamed bone flour (3 cwts) was better 

 than either, and in the Northumberland and Durham districts 

 2 cwts high grade basic slag is recommended in place of the 

 superphosphate. 



Where dung was applied the omission of potash 3 did not 

 prove serious in cool, moist districts, e.g. in Lancashire 3 , Wales 4 , 

 and Somerset 5 , or in land in good condition in Herts 6 . In these 

 circumstances, therefore, the grower need not be over anxious if 

 he cannot get potash, so long as he has dung; he can use 1 to 

 2 cwts of sulphate of ammonia, and 4 cwts of superphosphate 

 or 2 cwts of bone meal in addition to the dung. 



In the more forward districts on lighter soils, however, e.g. 

 Herefordshire 7 , Devon 8 , Bedford 9 , Wiltshire 10 , potash proved 

 more necessary, and greater efforts must be made to secure it. 



On peaty soils the dressings of sulphate of ammonia can be 

 reduced, and in the fens it can be dispensed with altogether. 



On clay fen land the following has worked well 11 : 



No dung, up to 8 cwts superphosphate, 

 and on clay silt lands: 



No dung, 4 to 6 cwts superphosphate, J cwt sulphate of 

 potash. 



On the whole sulphate of ammonia and superphosphate have 

 proved better than nitrate of soda and basic slag, both of which 

 rather tend to set up alkaline conditions favourable to scab. 

 Lime is to be avoided for the same reason. 



No grower should omit to spray the main crop varieties. 



West of Scotland Agric. Coll Butt. No. 51, 1909. 



Holmes Chapel Year Book, 1909. 



Lanes. C.C. Farmers' Bull. No. 13. 



Aberystwyth Kept. 1906. 



Somerset C.C. Sept. on Field Trials, 1900-1908 



Herts C.C. Leaflets, Nos. 6 and 7. 



Hereford C.C. Bull. No. 2. 



Devon C.C. Report, 1907-1909. 



Beds C.C. Report on Demonstration Plots, 1907. 



10 Wilts C.C. Results of Field Demonstrations, 1908-9. 



11 In the Northumberland experiments basic slag was better than super- 

 phosphate. 



