106 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Subsoil Watering. — Experience has demonstrated that surface 

 watering has great drawbacks in the maintenance of an undertaking 

 of this magnitude, evaporation being so great that, before water 

 percolates into the subsoil by surface watering, the bulk is evaporated. 

 To overcome this difficulty, the only alternative was to resort to sub- 

 soil watering by means of earthen pipes placed perpendicularly into 

 planting pits. These pipes vary in diameter from 3 to 4 inches, and 

 when filled with water convey to the subsoil their respective contents. 

 This has the great advantage of inducing by capillary attraction a 

 deep root action ; whatever quantity of water is so given is conveyed 

 some three feet beneath the earth as shown in the diagram on p. 103. 



Once roots have reached a depth of three feet they eventually 

 search for fissures in the rock, and the plantation is practically safe 

 from surface drought. This contrivance is only suggested for dry 

 track or torrid zones as occur in Upper India ; it would be quite 

 unnecessary in moist tracks, where the subsoil always contains a great 

 percentage of moisture, which, by itself, is sufficient to attract a deep 

 root action. 



Preparation or Growing of Saplings for Dry Zone Afforestation. — 

 It will be noticed that all dry zone vegetation is characterized by 

 deep rooting. The hardier the tree is, the more powerful may be 

 said to be its root action. Dry zone trees, as a rule, are somewhat 

 slow to grow in their young stage, and they usually mature their seeds 

 during the hot season, which enables them to fall to earth, to be blown 

 by prevailing high winds into recesses and depressions in sheltered 

 positions. With the advent of the rains, water usually collects in 

 small quantities in these depressions and enables the seeds to germinate, 

 but, after the rains are over and dry winds recur, the ground gradually 

 dries up and it becomes a question how to meet this first struggle. 

 It will be observed that many species practically die down to ground 

 level, and it is at that critical period that the foundation is laid for 

 their future. Practically speaking, only the root system remains, 

 and during the cold weather months, and the following year's dry 

 season, these roots shape themselves and suddenly throw out shoots, 

 sometimes far more vigorous than those which a plant that had not 

 to undergo the same hardship could do. 



It will be readily seen from this that the raising of suitable dry 

 zone trees for afforestation work of this kind calls for more attention 

 than at first seems necessary. Growing in open nursery beds of trees 

 that will eventually have to be transplanted into exposed forest 

 tracts does not succeed with all species. No growing of tap-rooted 

 species should ever be attempted in nursery beds, they should be 

 grown in deep pots or pipes. The latter has proved very successful 

 indeed and has the double advantage of admitting a deep rooting 

 from the beginning (fig. 11). At the time of planting, another pipe 

 of similar size filled with good earth can be placed below the pipe 

 in which the sapling has been grown. This will induce the roots 

 already jnade to continue their downward growth more rapidly. 



