STATE POMOLOGICAL SOCIETY. 57 



all these materials indefinitely in the amounts and times required, 

 and, unless proper assistance is rendered there must come a 

 time when production is materially reduced and off seasons 

 occur. 



On the other hand, it may be noted that part of the orchard's 

 product requires comparatively small amounts of the impor- 

 tant elements. This is especially true of the wood, even when 

 the annual production of mature trees is considered. Inci- 

 dentally this accounts for the fact that young trees are much 

 less likely to make a profitable response to fertilizer applica- 

 tions than those of bearing age. Such trees often respond very 

 well to manure or to any other satisfactory mulch, as shown in 

 three of our experiments considered elsewhere. This, how- 

 ever, is apparently due more to moisture conservation than to 

 any direct increase in fertility. 



The large amount of lime contained in the wood may have 

 some significance, because, as shown later in several of our 

 experiments, its application has resulted in considerable im- 

 provement in growtli. In the fruit, however, very little lime 

 is required, and hence its application should not be expected to 

 affect the yields materially, and this corresponds with our field 

 results. Moreover, the total eff'ect of adding lime alone is sur- 

 prisingly small, in comparison with the large amounts that are 

 taken up. Either these amounts are merely drawn in and 

 deposited mechanically, and hence are largely without physio- 

 logical significance, or else the average soil is still able to supply 

 the lime needed. 



With iron the case is very similar. This element is almost 

 universally present in agricultural soils and the total amount 

 required is so small that its addition can scarcely be expected 

 to produce any important effect. This also is borne out by such 

 experimental results as are now available. 



The fruit, on the other hand, carries a large amount of potash. 

 From this, one might suppose that its addition to the soil would 

 be very important in improving yields, and this idea has been 

 widely proclaimed, especially by those considering only the 

 chemical composition of the fruit. As indicated later, however, 

 most orchard soils are already sufficiently supplied with 



