STATE HORTICULTURAL SOCIETY. 213 



and other gases which exist in the atmosphere. And (as we have 

 shown before) as atmospheric air cannot penetrate an undrained 

 soil which is badly baked or filled with water, therefore fruit trees 

 which grow on such soils would be partially starved, because they 

 must necessarily be deprived of all of the inorganic plant food 

 which is not soluble in water. 



In dry seasons the soil is supplied with moisture in two ways, 

 to wit: by capillary attraction and condensation of moisture from 

 the atmosphere. By capillary attraction it rises from the sub-soil 

 upon the principle that water rises in an empty sponge or lump 

 of sugar. In the summer much water exists in the atmosphere, 

 and is held in the form of vapor by heat. This vapor can only be 

 changed to water by coming in contact with something which is 

 cold enough to condense it. When a hard, compact soil has been 

 plowed only four or five inches deep, but little atmospheric air can 

 penetrate deeper than the bottom of the furrows, and during the 

 season of growth the mellow soil near the surface is too warm to 

 condense the vapor which the atmosphere contains. But when a 

 soil has been stirred to the depth of ten inches and contains no 

 stagnant water, atmospheric air will circulate freely to the bottom 

 of the furrows, and as the lower part of the stirred soil is shaded 

 by that which is more elevated, it will be rendered sufficiently cold 

 to condense the vapor from the atmosphere. When the subsoil 

 of an orchard consists of blue clay, or other matter which is im- 

 pervious to water, but little moisture can be furnished by capillary 

 attraction for the use of trees during times of drouth, as but little 

 exists in such subsoils. In such instances, if we would prevent 

 the moisture in the atmosphere from being condensed in the soil 

 by shallow plowing or improper culture, our fruit trees must 

 necessarily starve. Very sandy soils are unsuitable for orchards, 

 because they lose water and plant food rapidly by leaching, and 

 because the roots of trees in them are more liable to be killed by 

 cold than in soils which contain more clay and retain more moist- 

 ure. Therefore, as orchard soils should be eeer moist and yet 

 never contain stagnant water, it will be readily seen that unusual 

 care is necessary in the selection of orchard sites. 



The greatest losses in the orchards through all parts of the 

 Northwest, have occurred after protracted late summer, or autumn 

 drouths, which were followed by severe winters. The fatal effiects 

 of the winter of 1872-3 will not be forgotten soon by a majority of 

 those who had promising orchards in northern Iowa and Minne- 

 sota. During the summer of 1873 I examined the roots of the 



