no AGRICULTURE OF MAINE. 



76 bushels per acre for the last four years. In the absence of 

 fertilization during three of those years, the average annual 

 gains from the mulch were 22 bushels per acre, which also hap- 

 pens to be the average shown by it for all three of the experi- 

 UKnts in Table V. 



When fertilization has been added in these "adolescent" or- 

 chards, however, the benefits from the mulch have usually been 

 reduced, and in the presence of manure they have disappeared 

 entirely, so far as the average yield is concerned. In other 

 words on these medium sized trees, the three-ton mulch of 

 strnw or other extra material has apparently been heavy enough 

 tc interfere somewhat with the action of the manure. This 

 interference has been less with the commercial fertilizers, es- 

 }>ecially in the case of growth, and it does not appear at all in 

 F-vperiment 221, as shown later. 



From the present data, therefore, it appears that such a 

 mulch as we are using can not be relied upon for annual gains 

 of more than 20 to 35 bushels of apples per acre in the younger 

 orchards, and not more than 75 or 80 bushels in those more 

 mature. From this, it is evident that one is restricted to the use 

 of relatively cheap materials in maintaining the mulch, if it is 

 expected to show a definite profit. Where the materials for it 

 can be grown between the rows, or can be obtained in such form 

 as swamp hay, buckwheat straw, or possibly damaged straw of 

 other kinds, its use seems to be practical in many cases, though 

 not in all. 



We have grown a great abundance of material for an initial 

 mulch by using rye between the rows of 5-year-old trees. This 

 is followed by a more or less permanent cover of white and red 

 clover, supplemented with hairy vetch. The latter plants are 

 used to maintain the mulch until driven out by grass or less 

 desirable forms, whereupon the interspaces may be re-tilled and 

 reseeded to leguminous plants. 



As compared with the other treatments in these experiments, 

 it will be noted that the mulched trees are usually retaining 

 their superiority in everything but color of fruit. Their margin 

 is considerably smaller, however, than that in the recently 

 planted orchards discussed earher, and in a few cases it dis- 

 appears entirely in favor of some of the tillage treatments. The 

 latter cases are found chiefly in the heavy soil of Experiment 



