426 MINNESOTA STATE HORTICULTURAL SOCIETY. 



principles should be kept in mind. These principles simply conform 

 to the general laws of plant growth. An indiscriminate use of the 

 ingredients in commercial fertilizers is nearly akin to the indis- 

 criminate use of patent medicines. A few simple home remedies, 

 however, are often effective and valuable and can be safely used. 

 So with commercial fertilizers, if properly used they give good re- 

 sults. One of the most frequent errors in the use of commercial 

 fertilizers is the application of the wrong fertilizer. This causes an 

 unbalanced feeding of the plant. 



In the use of plant food in commercial forms it should be the 

 object, (i) to supplement that which is in the soil and also (2) to 

 assist the crop in obtaining some element which, possibly, it may 

 have difficulty in assimilating. In case that one wishes to use con- 

 centrated fertilizers it should be remembered that nitrogenous 

 manures have a tendency to produce large leaves, rich green in color, 

 and to cause a growth of luxuriant foliage. If the plant is over 

 stimulated with nitrogenous food, there is a tendency to cause pro- 

 longed growth of the crop. While nitrogen is one of the most es- 

 sential and valuable plant food elements, it nevertheless produces 

 an unbalanced growth when not properly combined with other plant 

 food elements, or when used in excessive amounts. Take a potato 

 crop, for example. Suppose that a heavy dressing of nitrate of soda 

 and no other kind of manure were used. The result would be a 

 large growth of vines and leaves, and with a good water supply the 

 tops would remain green till late in the season. From the appear- 

 ance of the foliage and vines, an abundant yield of tubers would be 

 expected, but when the potatoes are harvested only a few small ones 

 are obtained. The small crop is not due to the fact that nitrogen 

 is of no value as a plant food, but it is clue to the fact that the nitro- 

 gen has not been properly combined with the other essential food 

 elements. If in place of part of the nitrate of soda some potash 

 and phosphate compounds had been used a balanced fertilizer would 

 have been secured, and a larger crop obtained. From the numerous 

 soil analyses which have been made in our chemical laboratory, 

 nitrogen appears to be one of the elements that is liable to be the 

 most deficient in the soil. The bulletins of our station have dealt 

 with this subject, the nitrogen of soils, so extensively that I will 

 refrain from considering it in detail. For general farming purposes, 

 nitrogen can be obtained at no great expense by the well known 

 method of simply growing clover and other leguminous crops. In 

 the case of the horticultural crops where concentrated forms of 

 nitrogen are required, some nitrogenous manures are frequently 



