19 1 o.] 



Hop Cultivation. 



887 



in increased weight of crop to moderate dressings of phos- 

 phates, and upon clay soils to very heavy phosphatic 

 dressings. 



Owing to the fact that phosphates, unlike nitrogen, are 

 not directly concerned with leaf production, but are concerned 

 with the ripening processes, excessive phosphatic manuring 

 need not be feared in the same way as excessive nitrogenous 

 manuring. It is, of course, true that after a certain point is 

 reached increases in the phosphatic manuring do not lead to 

 increased weight of crop, but little damage is likely to accrue 

 from such excess. 



The amounts of phosphates usually applied for heavy clay 

 soils deficient in lime are from 5 -10 cwt. of basic slag (since 

 this contains some lime) to be sown in the autumn. Super- 

 phosphate should not be used upon these soils. 



Upon loamy soils containing lime, 3-5 cwt. of super- 

 phosphate, or the phosphate equivalent of this in the form of 

 steamed bone flour or other bone compound, should be 

 applied in the early spring. Some growers delay putting on 

 phosphates till late in the summer, but these should be put 

 on early so as to become well mixed with the soil. There is 

 no danger of loss of phosphates from drainage as they are 

 rendered insoluble in the soil. 



Upon the lighter sandy loams phosphates are not so highly 

 important as upon the clay soils ; nevertheless, it is expedient 

 to supply a small dressing annually or biennially. Further, 

 since these soils are often deficient in lime, steamed bone flour 

 or phosphatic guano is the best form in which to supply 

 phosphates, or basic slag may be used; but superphosphate 

 and dissolved bones should not be applied by themselves 

 without the addition of lime. 



Potash. — The application of potash for hops is not so 

 important as phosphoric acid, because most of the soils upon 

 which hops are grown contain sufficient of this element in an 

 available form, or the deficiency is made good by the potash 

 in the dung. The value of potash to plant growth lies in 

 lengthening the period of growth of the plant and is therefore 

 mostly needed on sandy loams, which tend to dry out, and 

 upon these soils it is advisable to apply 2 or 3 cwt. of sulphate 

 of potash or double the quantity of kainit. 



