72 FERTILISERS CONTAINING NITROGEN [chap. 



of little service except in such cases as vine borders, 

 where the prime cost is not of very great moment but 

 the land has to remain without further manuring for 

 many years. The presence of oil in a sample of shoddy 

 is generally regarded as detrimental, since it hinders 

 the access of water and so delays the decomposition of 

 the nitrogenous material. But considering how rapidly 

 all oils and fats are attacked by bacteria, it is doubtful 

 if this objection is valid, and actual experiments are 

 lacking. 



The value of woollen rags as manure has long been 

 known, lililhe wrote in 1653: "Coarse wool, nippings, 

 and tarry pitch marks, a little whereof will do an acre of 

 land, there is great virtue in them. I believe one load 

 hereof will exceedingly well manure half an acre," and 

 at the beginning of the nineteenth century Arthur 

 Young recommended them for dry, gravelly, and chalky 

 soils. At the present day, though shoddy is used to 

 some extent in general farming in the neighbourhood 

 of cloth-manufacturing districts, and though a certain 

 amount is worked up into compound manures, it is 

 mainly consumed by the hop and fruit growers. Such 

 farmers are dealing with a perennial crop, the quality of 

 which is important ; in consequence they prefer a nitro- 

 genous manure which will come into action steadily and 

 continuously throughout the season, rather than an 

 active one which will at any time induce a sudden rush 

 of growth. As the plant continues on the same ground 

 year after year, the residues of slow-acting manures 

 which are not recovered in the first crop accumulate in 

 the soil. Eventually the land becomes stored with 

 manurial residues, which come into action — i.e., decay 

 and nitrify — pari passu with the growth of the plant, 

 because both the plant and the soil bacteria are similarly 

 affected by the variations in such factors as warmth and 



