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compelled to remain very near the surface and tlieref»'re must be ex- 

 posed to great heat in summer and to great cold in winter. Also, in a 

 compact clayish soil the root system is particularly subject to dry rot. 

 With regard to the chemical composition of the soil, we may say that 

 the oraDge tree requires a soil containing a high percentage of carbonate 

 of lime and oxide of iron, and only a moderate quantity of clay (alumi- 

 na). When the percentage of clay is very high, or wh«n the orange 

 tree is situated on a subsoil of clay, it produc s fruit having a very thin 

 rind, and a very luscious flavous, but unfortunately easily subject to 

 rot and cannot be much depended upon for exportation. This is the case 

 of some orange groves at the Boschetto. When the subsoil consists of 

 soft porous rock, the fruit is large, has a thick rind, the oil glands and the 

 aromatic properties are well developed. This may be observed in the 

 orange groves of Casal Lia, CasalBalzan and Uasal Attard. If the subsoil 

 is very hard and compact and therefore very dry, as the subsoil of the 

 orange groves at Musta, the fruit is small sized, the rind is thin, but 

 the pulp is very juicy and delicious. Fruit grown on such a subsoil 

 ripens early and is in every way suitable for exportation. Whatever 

 the quality of the soil may be, still we may grow the orange tree to 

 advantage, provided that the soil is so regulated that there will be a 

 perfect drainage. A layer about two feet in thickness, and consisting 

 of rubble and stones, and covered by two or three inches of thin rub- 

 bish will constitute by itself a perfect system of drainage to favour 

 the flow of superfluous water in winter. The layer of earth which 

 covers that of rubble should be two feet in depth and never less than 

 1 foot and a half. As the rootlets will hardly ever penetrate beyoud 

 the layer of rubbish, and as drought prevents the formation of roots 

 within six inches from the surface, we may say that the soil in which 

 the orange tree thrives is from twelve to eighteen inches in thickness. 



The orange tree does not exhaust the soil very rapidly. The pro- 

 duce of the orange tree are the fruit and the pruned branches so that, 

 strictly speaking, the soil is depauperated of its nutritive substances 

 for the same amount which these substances enter into the composition 

 of the fruit and the pruned branches. If the nutritive elements of the 

 pruned branches are again returned to the soil in the form of wood ashes, 

 we will find that, even after the lapse of several years, the orange 

 grove can hardly be said to be impoverished at all. In the raising of 

 crops of cereals and other annual vegetables we meet with the reverse. 

 In these crops we carry off both the fruit and the plant which pro- 

 duced it, or in other words the earth loses for ever all the nutritive 

 substances absorved by the action of the roots. ^Tow, the vast per- 

 centage of the weight of an orange, consists of water and hydrocar- 

 bons, and of a few nitrogen compounds which the tree receives directly 

 or indirectly from the air. The small amount of phosphates and 

 potash necessary for the formation of the fruit and the perfection of 

 the orduge pips is compensated by the stable manure which is sup- 

 plied to the orange grove at regular intervals of six or eight years. 

 1 he effect of a too liberal supply of stable manure on the orange grove 

 is the production of exuberant foliage and large fruit with a thiek peel. 

 The fruit loses much of its aroma and become fibrous. On the contrary 

 a soil very poor in nitrogen compounds produces tiny orange delicious 

 in flavour but unfit for commerce. The chemical manures which pre- 



