114 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



laud and the production of a better tillage, but on light land and for 

 gardening purposes generally it is best employed in a well-rotted condition. 

 Horse dung is considered a " hot " manure, while cattle or cow manure 

 is cooler. Pig manure is valued especially for fruit trees. One of the 

 chief advantages of farmyard manure is that it helps to retain moisture 

 in the soil, the manure adding humus to the soil and making it thus 

 more retentive. 



On the farm the value of farmyard manure is fully recognised ; 

 the difficulty is that there is not enough of it ; such difficulty, how- 

 ever, does not, as a rule, present itself to the market-gardener or the 

 horticulturist, and, in the case of market-gardening in particular, the 

 soil is so eonstantly and liberally stored with fresh supplies of stable 

 dung and vegetable and animal refuse as to practically transform the 

 original condition of the soil and to make it one rich medium of plant 

 food for many years to come. It is on account of this that the additional 

 manuring effected by the use of artificial fertilisers has to be considered 

 in quite a different light from that which rules in the case of the supply to 

 farm crops. In the latter, economy has to be strictly observed, the soil 

 is not previously enriched with accumulations of farmyard and other 

 manures, and it is practicable only to give such, artificial help as shaU 

 be able to bring in a paying return in the increased crop. Nevertheless, 

 even in the case of garden plants there is frequently an advantage in the 

 use of chemical manures. Thus, vines, fruit trees, and potatoes are all 

 benefited by the application of phosphates and potash in greater quantity 

 than even a liberal use of farmyard manure can supply ; while for 

 succulent vegetables, that are intended to make rapid growth, nitrate of 

 soda or Peruvian guano give a useful stimulus. Bones are used for 

 vines and fruit trees, along with potash salts, of which perhaps sulphate 

 of potash is the best form ; and for potatoes superphosphate of lime, with 

 sulphate of potash and sulphate of ammonia, makes as good an artificial 

 dressing as can be desired. 



In general, it may be said that the effect of phosphates and potash 

 is to produce quality, while that of nitrate of soda, sulphate of 

 ammonia, and similar forcing manures is to produce rapid growth 

 and stem and leaf development. With the latter comes a retarding 

 of the ripening period. In the application of chemical manures to 

 flowering plants these points require to be carefully borne in mind. 

 In the case of grass it has been shown by the Piothamsted experiments 

 how entirely the character of the herbage can be altered by the use of 

 artificial manures, the tendency of quickly acting nitrogenous manures 

 being to increase the grasses at the expense of the clovers, and to 

 bring about a coarse growth of the grasses, while the application of 

 manures of phosphatic and potassic nature is to produce a mixed herbage, 

 potash salts in particular benefiting the clovers. Hence, in the case of 

 a lawn, when a gardener wants to get a fine mixed herbage with clover 

 it is not well to apply liberally such quickly acting nitrogenous manures 

 as nitrate of soda or sulphate of ammonia, but to employ materials con- 

 taining phosphates and potash, such materials, e.g., as bone meal and 

 sulphate of potash, and what nitrogen is applied should be in the form 

 of organic materials which decompose slowly and yield their nitrogen 



