1 146 THE BOOK OF GARDENING. 



give useful results. In the same way, the application of potash 

 to soils which are very poor in nitrogen or phosphoric acid would 

 be comparatively useless. Then heavy loamy or clay soils nearly 

 always contain an abundance of potash and phosphoric acid in 

 a more or less unavailable condition, and much of these sub- 

 stances may be liberated to the plant by careful tillages, and the 

 incorporation of humus. "However, it is nearly always advis- 

 able," says Prof. Bailey, "in orchards which are bearing to add 

 these materials in the shape of concentrated manures." The 

 quickest results following the use of fertilisers will be seen upon 

 sandy soils. Two or three years often elapse after the applica- 

 tion of chemical manures to heavy lands before any decided 

 results are observed. In other words clay soils ordinarily show 

 quicker results from tillage operations than they do from the 

 application of fertilisers. The fruit-grower should never rely . ex- 

 clusively upon chemical plant-foods, because they contain no 

 humus, and the soil is apt to become hard and lifeless. 



The importance of humus matter as an ameliorator of the soil 

 is obvious, for when humus is absent sandy soils become too 

 loose, hot, and leachy, and the plant-food gets washed away, 

 while heavy clay soils bake in dry weather, and become hard and 

 impervious to the fibrous roots. 



In order that fruit may ripen and colour satisfactorily, the 

 roots of the trees should be encouraged to luxuriate as near the 

 surface of the soil as possible, so as to get all the benefit from 

 the action of the sun's rays. 



It has been found that diseased and unproductive conditions 

 of Apricot, Nectarine, and Peach trees are largely due to an 

 excess of silica in the soil, and a deficiency of nearly all the 

 other mineral constituents. In other words, an unproductive 

 condition indicates soil exhaustion, which is remedied by the 

 application of suitable manures. 



Manures Applicable to Strawberry Culture. 



Strawberry-growers sometimes complain that when the plants 

 forced in pots are grown with guano or other phosphatic manure, 

 it is found that, although many blossoms are produced, they do 

 not set, or if they do, the fruit is inferior in size and quality to 

 the smaller quantity produced by less vigorous plants grown in 

 poorer soil. There is no doubt that a small amount of kainit 

 or other potash manure, added to the usual quantity of guano, 

 would greatly improve the size, yield, and quality of the fruit. 



For the growth of Strawberries the soil should be naturally 

 fertile, deeply cultivated, and liberally manured eyery year. High 

 manuring for this crop is an essential condition for successful 

 growth, because not only has the fruit to he, provided for, but 

 there is a considerable drain upon the plants in the production 



