OCTOBBR 18, 1906. 



The WccHy Florists' Review^ 



H07 



Dahlia F. M. Stredwick, YeUowith White. 



FERTILIZERS AND THEIR USE« 



[Synopsis of a paper by Prof. R. Harcourt, 

 of the Ontario Agricultural College, dellyered 

 before the Canadian Horticultural Association, 

 at Guelpb, Ont., August 29, 1006.] 



It is well known that in order to secure 

 the best results in animal production, 

 careful selection and breeding must be 

 associated with good feeding. The same 

 is true with reference to the growth 

 of plants, for it is just as essential that 

 there be quick, vigorous growth in plant 

 life as in animal life. The infant plant 

 requires warm air, sunshine, and abun- 

 dance of easily absorbed food. 



Origin and Needs of a Plant. 



The young plant starts from a seed. 

 The seed contains an embyro, or germ, 

 which is extremely rich in albuminoids, 

 fat, phosphates, and potash. It also 

 contains a store of concentrated plant 

 food, intended to nourish the young 

 plant until the roots and leaves are suf- 

 ficiently developed to gather their own 

 supplies. 



The future health and vigor of the 

 plant will depend on the amount of food 

 available to the tiny rootlets sent out 

 by .the young plant, that the soil is 

 warm, that there is an abundance of 

 sunshine, and that it has a sufficient 

 supply of oxygen and carbon dioxide. If 

 the roots and leaves quickly come in 

 contact with nourishment the develop- 

 ment will be rapid. The plant requires 

 oxygen for respiration; it gives oflf 

 water from its lungs, or the leaves; it 

 assimilates food; it breathes, that is, 

 gives off carbon dioxide as a result of 

 the oxidation of its food. 



In- all this it is similar to the animal. 

 But it goes even farther and collects its 

 food from the simple substances, such 

 as carbon dioxide and various soluble 

 salts found in the soil, and from these 

 builds up the complex sugars, starches, 

 fats, and albuminoids. Thus it will be 



seen that the plant must prepare its 

 own food. From what has been said, 

 it is evident that the plant grower has 

 just as wide a field for work as the 

 stock breeder, and that the thorough 

 understanding and development of plant 

 life affords an even wider field for good 

 judgment and study than the animal 

 life. 



Sources of Food. 



The plant's food is derived from the 

 atmosphere and from the soil. From 

 the atmosphere it gathers carbon diox- 

 ide and oxygen, and some plants collect 

 nitrogen. There is an abundance of air 

 around the leaves of the plant, but if 

 the soil is not open and porous, there 

 may not be enough in contact with the 

 roots, for air in the soil in which plants 

 are growing is essential to the life of 

 the plants. This ventilation of the soil 

 is needed to supply the oxygen required 

 in germinating the seed and to permit 

 the roots to live. It is also required to 

 supply free nitrogen for the use of the 

 free nitrogen-fixing germs,- and to re- 

 move the excess of carbon moxide which 

 is set free in the soil, v .\- . " ' , 



Nitrogen. 



From the soil the plant derived ni- 

 trogen, chiefly in the form of nitrates, 

 and ash substances. Fortunately, al- 

 though a great many different elements 

 are absorbed by the plant, only four re- 

 quire particular attention. These are 

 nitrogen, potassium, phosporus, and 

 calcium. In the • absence of nitrogen, a 

 plant makes no appreciable growth. 

 With only a limited supply, a plant be- 

 gins its growth in a normal way, but as 

 soon as the available nitrogen is used up, 

 the lower and smaller leaves begin grad- 

 ually to die down from the tips, and all 

 the plant energy is centered in one or 

 two leaves. Nitrogen is one of the main 

 constituents of chlorophyll, the green 

 coloring matter of plants, hence with a 

 limited supply of nitrogen, the leaves 

 will have a sickly yellow color. 



Phosphorus. 



Phosphorus, in the form of phos- 

 phates, is found in all parts of the 

 plant, but tends to accumulate in the 

 upper part of the stem and leaves, and 

 particularly in the seed. Its function 



Dahlia Floradora^ Red. 



