244 AGRICULTURAL EXPERIMENT STATION. [Jan. 



constituents of the plant. It has been noticed that many of 

 our cultivated plants are more or less susceptible of change 

 in that direction, owing to a liberal application of one or the 

 other essential constituent. 



Fifth. It has also been shown that the particular form 

 of the various articles of plant food, as well as the special 

 associations in which they may be applied, exerts quite fre- 

 quently a decided influence, not only on the quantity of the 

 crop, but also on its quality. 



The observations referred to above {fourth and ffth) de- 

 serve particularly the serious attention of all parties engaged 

 in the raising of industrial crops, as well as garden crops and 

 fruits ; in fact, wherever a special quality of the product 

 afl'ects the commercial value of the same. We know that 

 whenever such changes are made they are as apt to be in our 

 favor as against our best interests. The history of the suc- 

 cessful production of many of our industrial crops furnishes 

 us with an abundance of illustrations of the existence of 

 such relationships, as in the case of sugar-producing plants, 

 tobacco, etc. 



Sixth. The natural resources of the soil in available plant 

 food have proved, as a rule, ultimately insufficient for a 

 remunerative management of the farm, the garden and the 

 orchard. Older systems of agriculture have failed on account 

 of a scanty supply of plant food, and many failures in our 

 present system of management will most likely be ascribed 

 at some future day to an indifferent application of the essen- 

 tials of plant food. 



From the foreffoin^ record of well-established conclusions, 

 derived from actual observation in the vegetation house, the 

 field and the garden, we can draw, if we desire, some valu- 

 able lessons for our guidance in the practical management of 

 the various branches of agricultural and horticultural industry. 



A careful consideration of the points stated cannot fail to 

 impress all interested parties with the fact that to manure 

 our lands efficiently means to-day something more than to 

 incorporate into the soil an exceptionally liberal amount of 

 some incidental refuse matter of ill-defined composition, as 

 barn-yard manure, vegetal)le compost or wood ashes. Both 

 good economy and the desirability of securing a successful 



