1922.] 



Cultivation of the Hop Crop. 



1013 



that, unlike dung, shoddy contains no potash or phosphates and 

 consequently applications of these must be increased. 



In normal practice 20 to 30 loads of dung per acre should be 

 applied each year during the early life of a hop-garden, or as a 

 substitute 2 to 3 tons of shoddy. The usual time at which the 

 dung or shoddy should be applied is during autumn or winter, 

 to be ploughed and worked into the land, yet dung may be 

 advantageously applied in summer provided it is properly treated 

 — preferably it should be spread along close to the hop-hills and 

 either ploughed under cover or covered up with soil by forks so 

 as to prevent loss of ammonia into the air. This latter practice, 

 '" summer-dunging," is economical from another aspect; it is 

 well recognised that dung, no matter how well it may be stored, 

 constantly loses nitrogen. Russell* and Richards have shown 

 that these losses may be as much as 30 per cent, during three 

 months' storage; such loss of nitrogen falls almost exclusively 

 on the most soluble and therefore most valuable constituents of 

 the dung; if, therefore, the dung made during the latter part 

 of winter is judiciously applied to the hops, this soluble and 

 available nitrogen is converted to good use by the hop roots, and 

 the less soluble constituents, the decaying straw, etc., are no 

 less valuable to the soil for textural and other purposes by this 

 method of application. It is to be remembered, however, that 

 there is a right and a wrong time to apply dung in summer ; it 

 will do little or no good if application is delayed till August, 

 but will give best results if it is applied so that it is available 

 for the hop roots just before " burr " begins to be formed. 



Quick-acting Nitrogenous Manure. — We have already seen 

 that in order to obtain best results the hop plant requires to be 

 supplied with a continuous and ample supply of nitrogenous food 

 from the time when growth begins in the spring until the forma- 

 tion of the i; burr " is complete. We have further seen that the 

 application of organic manures such as dung and shoddy as well 

 as the organic matter already present in the soil leads to a con- 

 tinuous, though irregular, supply of available nitrogen; this 

 supply following the dead winter season is likely to be ample 

 for the needs of the hop during the early stages of growth, but 

 may not be sufficient to produce the vigorous growth required 

 whilst the " burr " is being formed. It is. therefore, generally 

 necessary to supplement the slowly available dung and soil 

 nitrogen with some quick-acting nitrogenous fertilizer. 



• See Leaflet No. 93. 



