104 STATE POMOLOGICAL SOCIETY. 



frequently observed that the soil under the rye and alsike plats 

 was practically dust dry, while that under the adjacent vetch 

 was turning up almost too wet for plowing. Under such condi- 

 tions, the ordinary clovers have proved to be about intermediate 

 in the moisture content of their soils, with the advantage some- 

 what in favor of the crimson, — especially after seed formation 

 had begun, with its accompanying check on vegetative growth, — 

 while the conditions under the frost-killed annuals were more 

 nearly like those under the vetch. 



The importance of these differences in moisture can be appre- 

 ciated when it is remembered that in the average soil it is only 

 the moisture in excess of 8 or lo per cent that is available to 

 plants. On some of these plats, therefore, the trees were evi- 

 dently practically in a state of drought, while those on the vetch 

 and similar plats were almost too well supplied with moisture. 



In the present experiment, crimson clover has come next to 

 vetch in its relation to tree growth. This again is not surpris- 

 ing, but the low position of the mammoth and medium red 

 clovers is wholly unexpected, since they seem to be very much 

 like the crimson clover in their more important characters. It 

 seems quite probable that the growth deficit on the latter plots 

 is due to some unfavorable feature of the immediate soil con- 

 cerned, rather than to any action of the clovers themselves, 

 because even their growth has not been very satisfactory until 

 the last two seasons. It is also possible that the greater amount 

 of winter-killing on the crimson clover plats, which evidently 

 reduces the growth and loss of moisture in the spring, may have 

 something to do with its advantage. 



In the case of all the other crops, the present effects on the 

 trees are doubtless largely due to their relative influence on the 

 moisture supply, which has already been noted as very import- 

 ant in this orchard, in the discussion of Experiment 331. The 

 rye influence has not been as bad as might be expected, probably 

 because it was usually sown late, — not earlier than the first of 

 September, — and it has always been mowed immediately around 

 the trees as soon as it showed any important growth in the 

 spring. The cow peas and soy beans, on the other hand, are sown 

 some time between June 25 and July 5. The period of cultiva- 

 tion, therefore, is much reduced for the trees and the crops 

 make a vigorous growth, thus undoubtedly competing rather 



