84 AGRICULTURE OF MAINE. 



ence of fertilization is relatively short, and where it does do a 

 little good at first, that it will soon run out in its influence. That 

 might be the case if your gains are coming from caustic mate- 

 rials, such as gypsum or lime or something of that sort, which 

 act merely as whips on the soil and push it to a further state of 

 exhaustion. In such case you might get gains for a year or two 

 or three, and then your soil would drop back. But if you are 

 putting actual plant food upon the soil and using a really suit- 

 able fertilizer, there is certainly no reason whatever for the 

 influence to decrease with age, and in the second set of results 

 that I showed you I could have pointed out that in the sixth 

 year of that experiment we had by far the largest gains we ever 

 had in it. If it hadn't been for the frost this year in the first 

 orchard, we would have gotten our largest gains from it also in 

 the sixth year, judging from the indications. 



Also, in another experiment on general farm crops that is 

 going on at the college, which is now in its 33d year, I might 

 say that the fertility of those plots that have received a proper 

 fertilization has been absolutely maintained for 33 years and, 

 in some cases, it is even better than it was when it started, and 

 they have never had a pound of manure or outside vegetation 

 put back upon them. I certainly would not want to say any- 

 thing that would upset the system of a whole community, but 

 these are the results that our experiments have shown. I am 

 not certain our results will apply to your conditions, and I would 

 not recommend you to change your methods all over until you 

 have tried the change on a comparatively small portion and 

 seen what it will do, and then, if it works with you as it has 

 worked with me, why extend it over the balance and cut out 

 that extra work. 



Prof. Woods: \\'e want to set over against these experi- 

 ments which are upon particular soil in Pennsylvania, experi- 

 ments upon another soil in New York that were carried on for 

 16 years, in which absolutely no trace of benefit whatever could 

 be found from the use of fertilizer. 



Prof. Stewart: Well, since this contrast has been raised, I want 

 to call attention to the difiference between the results in New 

 York and those in Pennsylvania. The results in New York were 

 obtained from a single soil, and our results are obtained from 

 ten different soil types and a far greater number of trees. Their 



