AMERICAN INSTITUTE. 465 



tion, for the purpose of at once increasing the growth of the crop, 

 or they are used on fallow land for the purpose of storing up in 

 it a certain quantity of nutritive matter ready to be absorbed by 

 the crop that is to follow. 



This difference of object requires a similar difference in the 

 nature of the liquids to be employed, and in the method of using 

 them. When it is intended to spread it on living vegetation care 

 must be taken, first, that the manui'e is not so strong as to burn 

 the crops, nor so diluted as to reduce the benefit merely to that 

 arising from irrigation with so much water; secondly, the manure 

 should be distributed at a proper time relatively to the age of the 

 plants, to the season, and to states of the atmosphere. On the 

 other hand, w^hen the object is to spread liquid manure on fallow 

 land as a store of nourishment, the strength of acridity of the 

 manure need not be dreaded; neither is there any fear that the 

 time may not be suitable. The first method requires more care 

 and attention, but gives larger immediate results. The second is 

 more certain, easier, and more generally applicable. 



The quantity of the water to be applied should be varied. 



1. To the object of the culture : when for leaves, more w'ater 

 should be given than when for flowers; less water should be given 

 when for fruits and grains. 



2. The depths of the roots : the application should be more 

 frequent to the plants the roots of which are superficial, less fre- 

 quent to deeper roots. 



3. The structure of the foliage : those T^hich evaporate much, 

 such as plants with large leaves, more frequently than perennial, 

 or plants wath thick leaves. 



4. In regard to the stage of vegetation, it is important to bear 

 in mind that young germinating plants require light and frequent 

 waterings; those that are growing w^ell abundant waterings, and 

 wdien the fruit or seed is maturing the waterings should be infre- 

 quent. Those plants that have been transplanted abundant 

 w^atering. 



5. The nature of the soil, according to which these rules must 

 be modified. The lighter the soil the more frequent and plentiful 



