92 THE PHYSIOLOGY OF PLANTS 



In the case of freshly-transplanted trees, again, manure of 

 any great strength should be avoided. The very highly con- 

 centrated solutions of nutritive substances which are formed 

 in the soil under these conditions cannot be utilised by the 

 injured root system. We always supply the roots as directly 

 as possible with some compost, if we do not fill the entire hole 

 with it, and this is quite sufficient to see the tree through the 

 first year. If further material is available, a little decom- 

 posed manure may be spread over the surface of the soil. This 

 will gradually become washed free of its nutritive substances, 

 which will find their way into the soil below. We do not, 

 however, wish to say that no manures should be put into the 

 trenches. If the soil is very poor, the addition of manure 

 (especially of animal dung) will probably be very beneficial ; 

 but it should be so placed that the roots will only make use 

 of it in the second year. 



In manuring trees which have not been transplanted, mineral 

 manures are often preferable to animal manures, because the 

 decomposition of the latter takes place very slowly in the soil, 

 which is usually very dry under the trees. It is also more 

 difficult to apply stable manures, and the effisct produced by 

 them is not always the desired one. Supposing the trees 

 show a tendency to produce strong branches, and you wish to 

 produce fruit-buds, animal manures are of much less use than 

 the addition of phosphoric acid alone in the form of ground 

 Thomas phosphate, &c. If the tree does not form proper 

 woody shoots, a manure rich in nitrates and potassium should 

 be applied. 



For large trees it is best to introduce the manures into 

 trenches dug round the tree. 



Such a trench should be made about the breadth of a spade, 

 and carried round the tree at about the same distance as the 

 longest branches. It may even be closer up to the stem, but 

 it should be made so deep as to reach the network of roots, 

 the younger ones of which may be cut through. In the place 

 of the excavated earth, compost, decayed manure, or, in absence 

 of the latter, ordinary earth mixed with fresh dung, horn shav- 

 ings, or other insoluble refuse, should be placed. The best 

 efiect is produced by rich compost. 



