162 



Fertilisers 



[PT. Ill 



Uromyces betae; the wheat is always subject to rust and 

 the tips of the leaf begin to die early in the season and 

 then the edges turn yellow for some distance down. 

 Elsewhere also dressings of potash have enabled plants 

 to withstand pests: flax in Ireland, tomatoes in glass- 

 house culture, spring oats affected by eelworm have all 

 furnished cases in point. Potash manures also tend to 

 counteract rankness of growth and therefore find valu- 

 able apphcation for glasshouse and nursery work. 



In farm practice considerable quantities of potash are 

 supplied in dung and liquid manure where this is used 

 (p. 177). Potassic salts are given usually to potatoes, 

 mangolds or flax: the cereals in the rotation can then 

 very well take up the unused material. On the whole 

 kainit is better for mangolds while the sulphate or 

 muriate is better for potatoes and flax ; between sulphate 

 and muriate, however, there is little to choose^. Where 

 potash is wanted for grass land kainit is perhaps the 

 better and on the whole cheaper: the results of the 

 Yorkshire experiments ^ which are typical of many 

 others are given in Table VIII. 



Table VIII. Yorkshire experiments on meadow hay. 



No manure 

 Nitrate of soda 



Cwts. per ac) 



( super 



Nitrate of soda + \ steamed bone flour 

 V. slag 



Nitrate of soda + phosphates + potash as 



' sulphate 

 muriate 

 kainit 



Garforth 

 32 

 43 

 44 

 43 

 44 

 43 

 45 

 42 



Horton 

 36 

 43 

 45 

 45 

 45 

 49 

 51 

 52 



1 loth Annual Report, Durham Coll., 1902, p. 30; Journ. Irish Dept 

 Agric. XIII. 254; Leeds Bull. No. 58, pp. 19 and 20. 

 * Ouide to the Garforth Experiments, 1913, p. 3. 



