ON MANURES. 1 121 



supply of manure to the waste caused by the growth and 

 removal of his crops, and to the unavoidable loss by drainage, 

 he will keep up the fertility of his soil to the degree in which 

 he found it. And if he gives more judiciously he will gradually 

 increase the fertility of the soil, and enable it to withstand 

 drought and other adverse influences more effectively. 



Respecting the need of fertilisers for orchards, Professor 

 Voorhees writes as follows : " It is argued by many, and some- 

 times by those who should know better, that fruit-growing is 

 quite similar to growing timber-trees ; that the question of soil 

 exhaustion is not a matter of very great importance, provided 

 the soil is well cultivated; and that all soils contain sufficient 

 quantities of the food-elements to insure the relatively small 

 available supply required from year to year. It is admitted 

 that on soils of good mechanical condition, well drained and 

 cultivated, which are naturally adapted for fruit as well as other 

 crops, because well supplied with the essential constituents — ■ 

 nitrogen, phosphoric acid, potash, and lime — the exhaustion 

 arising from the continuous removal of crops will not become 

 apparent for a long time, but it should be emphasised that it 

 is only upon soils which possess these characteristics that the 

 growth of fruit, even poor fruit, can be continued for any con- 

 siderable period without the application of manures." 



Manures and their Application, 



Formerly, all substances which were incorporated into the 

 soil for the purpose of enriching it, were designated manures. 

 Since the introduction of commercial fertilisers in recent years, 

 the meaning of the word has changed somewhat, for according 

 to their origin, or the kind of plant-food material they supply, 

 manures are spoken of as : — ■ 



(i) Animal Manures. — These are the excrements of domestic 

 animals. The term "excrements" has been substituted for the 

 ancient word dung, the meaning of which was somewhat 

 ambiguous. Excrements are the solid and liquid voidings of 

 animals, unmixed with litter. These are characterised by the 

 large quantity of nitrogen they contain, and the ease with which 

 they decompose and yield their fertilising matter in available 

 forms. To this class of manures would belong guano, desiccated 

 blood, bones, bone-meal, fish, and bone superphosphate. 



(2) Vegetable Manures comprise ordinary farmyard and 

 stable manure, having a variable proportion' of plant-food 

 constituents, seaweeds, vegetable refuse, oil-cakes, &c, which 

 undergo decomposition more or less slowly. 



(3) Mineral Manures, which are extracted from the mineral 

 rocks of the soil, and yield the ash constituents to plants, which 

 may include sulphate ammonia, obtained from coal-tar, potash, 



4 c 



