102 AGRICULTURE OF MAINE, 



do not expect much response to fertilization in the case of most 

 young trees. 



The response here is rather irregular, but in general it indi- 

 cates the value of nitrogen and phosphates, which corresponds 

 with our results on this same type of soil in the Johnston or- 

 chard, in which older trees and both yields and growth are 

 involved. The chief irregularity here appears in Plats 8 and 9, 

 in which manure is showing less effect and the lime more effect 

 than would naturally be expected in the light of their behavior 

 in our other experiments. This irregularity appears to be much 

 greater in the percentages than in the actual average gains on 

 these two plats — an effect which is brought about by the abnor- 

 mally strong growth on the check Plat 7, possibly due in part 

 to leaching or cross-feeding from Plats 6 and 8. Beyond this, 

 however, we can offer no further explanation of the present 

 results in this experiment, and we are awaiting further returns. 



RESULTS FROM COVER CROPS AT THE PENNSYLVANIA STATE 



COLLEGE. 



Similar data, bearing especially on the value of cover crops, 

 are available from another of the experiments at the College. 

 The crops used in this experiment are stated in Table IV. 



These crops are plowed under annually and the usual orchard 

 tillage is given on all plats excepting the alfalfa. The latter 

 plat was plowed only at the beginning of the experiment, at 

 which time the soil was limed, manured and inoculated, and 

 otherwise prepared as usual for alfalfa. The liming also has 

 been extended to the other plats. The initial stand of alfalfa 

 was unsatisfactory and it was therefore turned under at the 

 beginning of the next season and immediately seeded again to 

 the same crop. Since then nothing has been done with this 

 plat, except to cut the alfalfa two or three times a season and 

 apply it as a mulch about the trees. The mulch obtained in this 

 way has been considerably more than was needed to keep down 

 the growth immediately around the trees, and some of it, there- 

 fore, has been hauled away. As the mulched area enlarges, 

 however, this condition will not continue. The relative value 

 of the various crops, as indicated by the growth of the trees, is 

 shown in Table IV. 



