24 VEGETABLE GAEDENING. 



chiefly concerned with assimilation, and the produc- 

 tion of starch, sugar, etc., in plants. It is especially 

 beneficial to tubers, roots, fruits, and seeds, im- 

 proves the quality and promotes early ripening and 

 maturity. 



Lime. See under Fertilisers. 



ORGANIC MANURES. 



Farmyard Manure. This is the oldest and most 

 popular manure, and it is in itself a complete fer- 

 tiliser, containing as it does the three most important 

 plant foods, nitrogen, phosphates, and potash. These 

 elements are present in varying proportions, accord- 

 ing to the kind of feeding and age of the animals 

 producing the manure, as well as to other conditions, 

 the principal one being the care with which it has 

 been treated. But, although it is a complete fer- 

 tiliser, it is not well-balanced, as it is invariably 

 richer in both nitrogen and potash than it is in phos- 

 phates, the latter being retained by the animals for 

 the building up or production of bone, muscle, milk, 

 etc. Farmyard manure is comparatively poor in 

 phosphates ; and the great bulk of soils, while they 

 frequently contain a considerable reserve of nitroge- 

 nous material, are also deficient in this ingredient. 

 To remedy this lack of phosphates, a general applica- 

 tion over the whole area of a phosphatic fertiliser 

 suited to the particular soil, as will be indicated later, 

 and applied periodically, should be included in all 

 systems of manuring if the soil is to be maintained in 

 a properly balanced condition. Besides introducing 

 plant foods directly, farmyard manure is of great 



