SOILS AND FERTILIZERS 469 



slowly decomposing manures, such as barnyard manure, leather 

 waste, horn refuse, wool waste, leaf mold, tobacco stems, etc., is thus 

 seen to have more or less of a scientific basis. Frequently, however, 

 it is desirable to stimulate the growth and fruitfulness of the trees, 

 and for this purpose more active fertilizing materials than the above 

 are needed. In selecting and mixing the latter, the fact that fruits 

 are "potash feeders" should be taken into consideration. 



Probably there is no better fertilizer for fruit trees than a mix- 

 ture of muriate of potash and ground bone (1 part of the former to 

 l x /2 parts of the latter). A good practice is to apply this mixture to 

 clover or some other leguminous crop which is turned under as a 

 green manure, and in addition, where tobacco stems can be obtained 

 cheaply, to apply these about the trees. Wood ashes or cotton-hull 

 ashes may be substituted for muriate of potash, if these products can 

 be obtained at reasonable prices. 



Small Fruits. The fertilizer requirements of small fruits are 

 similar to those of orchard fruits, but being as a rule more rapid 

 growers they can utilize to advantage heavier applications of soluble 

 fertilizing materials and do not derive the same benefit as orchard 

 fruits from slowly decomposing manures. 



The importance of taking into consideration all the factors 

 which influence the use of fertilizer can hardly be overestimated. A 

 plant must have each one of the essential fertilizer constituents 

 present in an available form or its growth will be hindered in propor- 

 tion to the deficiency of the lacking constituent. When the soil 

 is rich in a given fertilizer constituent which is present in an avail- 

 able form, it will not be detrimental to the crop if that constituent 

 is omitted in the fertilizer applied. If, on the other hand, the soil 

 be deficient in a fertilizer constituent that is omitted in the fertilizer, 

 the crop yield will decrease in proportion to the insufficient supply 

 of that constituent. When mixing fertilizer for the different crops, 

 the amount of fertilizer which has been added to the soil in barnyard 

 manure, green manures, and leguminous crops should be considered, 

 and no more of any one fertilizer constituent should be applied 

 than is likely to be beneficial. A crop is not benefited by supplying 

 it with more fertilizer than is needed. An excess of one or more 

 fertilizer constituents not only fails to increase but often decreases 

 the yield of crops, as shown both by experiments and by field prac- 

 tice. 



To properly adjust the fertilizer constituents the farmer must 

 study his conditions. No definite quantity or proportion of fertilizer 

 constituents can ever be given that will meet me needs of a crop 

 under all conditions. The rotation of crops, the growing of legumes, 

 the use of crops for green manuring, the application of barnyard 

 manure, the methods of preparation and cultivation, and the char- 

 acter of the soil will always be factors which must be taken into 

 consideration when using commercial fertilizer. 



The kind and quantity of fertilizer required to produce the 

 most economical yields are greatly influenced by the rotation of crops. 

 Tobacco, for example, takes from the soil approximately ten times 



