ARTIFICIAL MANURES AND HORTICULTURAL PRACTICE. 45 



Table IV.— continued. 





In Plants 



In Fruit 



Total 



Constituents in the Ash : 



Per cent. 



Per cent. 



Per cent. 



Potash ...... 



891 



19-7 



108-8 



Soda 



6-4 



0-9 



7-3 



Lime 



102-7 



7-9 



110-6 



Magnesia 



161 



0-7 



16-8 



Phosphoric acid .... 



35*3 



5 - 4 



40-7 



Silica and iron oxide 



433 



5-3 



48-6 



Other elements .... 



120-9 



8-8 



129-7 



Total 



413-8 



48-7 



462-5 



Table IV. illustrates the composition of the strawberry plant 

 and also of the strawberry fruit. The data show the amounts, 

 which are given in pounds, of the various constituents that would 

 be carried off from an acre of land by the growth of an average 

 crop of strawberries. The last column of the table shows that 

 more than two tons of organic matter, 105 lbs. of nitrogen, and 

 nearly 500 lbs. of mineral ingredients are required per acre to 

 sustain and build up the fabric of the strawberry plant and its 

 proper proportion of fruit. Fortunately, by far the greater part 

 of the dry substance of the strawberry plants is furnished from 

 natural sources that are practically inexhaustible. Water, in 

 the condition of rain and dew, and the carbonic acid gas, which 

 abounds in never-failing quantity in the air, build the great 

 bulk of the tissues of plants ; therefore, for these constituents, 

 except in times of drought or in culture under glass, we need 

 have no anxiety. But moisture and carbon are useless without 

 other constituents, which have to be derived from the soil. 

 These are nitrogen and the mineral substances. Of all the 

 elements found as entering into the composition of the strawberry 

 as of other plants, we lay the greatest stress upon nitrogen, 

 potash, and phosphoric acid, because, in addition to being- 

 necessary for the growth of even the smallest crops, they are not 

 in sufficient quantity or in such an available condition that 

 remunerative crops of strawberries can be obtained without a 

 fairly continuous supply. We see from the figures given in 

 Table IV. that the essential constituents of the strawberry plant 

 and also of its fruit are nitrogen and potash. 



Phosphoric acid stands third in order of requirement, the 



