140 STATE HORTICULTURAL. SOCIETY. 



plying a germinating seed with the elements found by the chemist, it has 

 been shown that a perfect plant can be grown which, under proper condi- 

 tions of light, temperature, moisture, and air will mature seeds. 



It was found that plants contain a very large per cent, of water, gen- 

 erally seventy- five to ninety per cent, or more, whilt; a large proportion of 

 the remaining bulk consists of carbon in the form of woody fibre. 



In all arable soils the water is present in such abundance that the roots 

 can obtain all that is needed, and with it they take up in solution the 

 mineral food that is furnished to the plants. If we burn a plant the water 

 is first given off, the carbon will next be oxidized and changed into car- 

 bonic acid, and the nitrogen and other gaseous elements will also be given 

 off into the air, and we shall have remaining what we commonly speak of 

 as the ash of plants. 



In this we find not only the potash and phosphoric acid, but the lime, 

 magnesia, iron, sulphur, and other mineral elements that have been taken 

 from the soil. 



THE DEMAND FOR PLANT FOOD. 



If we would grow plants successfully we must place at their disposal, in 

 a soluble form, and in amounts relatively the same as found in the ash, the 

 same elements as are obtained when we burn them. These elements make 

 up what we speak of as the food of the plants. 



As a rule, a virgin soil has an abundance of all these elements, but after 

 cropping for a series of years, one or more of them can not be obtained — 

 particularly after crops have been removed — and the necessity arises of 

 replacing those that are lacking. On light soils deficient in hamus, the 

 supply of nitrogen is generally the first to fail, and later on the phosphoric 

 acid and potash will not be available in sufficient quantities to return the 

 best results. As a rule, the other ten elements found in plants will be 

 present in a soluble condition in the soil in sufficient quantities to afford 

 a supply for plant growth, and little attention need be paid to them. We 

 must remember, however, that small as is the amount required of some of 

 them, such as sulphur and iron, that plants can not be grown without 

 them, and as they can be readily obtained, the application of some ferti- 

 lizer containing them may be sometimes desirable, if made in an experi- 

 mental way. Having thus hastily attempted to point out the nature of 

 the plant food, and the increasing demand that plants make for it, let us 

 see what the available supply is. 



nature's supply of FOOD. 



The first source of plant food is the soil itself, and all our efforts should 

 be turned to the endeavor to so handle it that we can render available as 

 much as possible, and at the same time so treat it as to guard it against loss. 



Nature, through the action of frost, water, and air, is continually at 

 work at breaking up the soil particles, changing them into soluble forms, 

 and then taking them into solution, ready to be used by the plants. 



Much can be done by cultivation to hasten the development of plant 

 food in the soil, as by plowing we can promote the action of the air, and if 

 the soil is kept frequently stirred through the growing season, the moisture 

 will be conserved and the solution of the soluble salts will be aided. If 



