No. 4.] COMxMKKCIAL FKUTILIZKKS. 141 



come such as to make it necessary to apply larger quantities 

 of fertilizer. 



(^UKSTioN. What do you term a " larger (quantity " ? 



Dr. VooKiiKKS. Two thousand jxmnds per acre. You say 

 that at the present time you use about 1,200 pounds per 

 acre. After your potatoes come off there is nothing more 

 on your laud until the spring, when the barley comes; and 

 you follow the barh'y with hay, and then with potatoes again. 

 I should not call that a well-balanced ration. 



Question. Do you advise the raising of celery wholly 

 on commercial fertilizer ? 



Dr. VooKJiEKs. I would under proper conditions as to 

 moisture and plant food. 



Professor Bkooks. I think a large proportion of humus 

 in the soil is essential for celery, and that this can be sup- 

 plied, in many localities, to best advantage in manures; be- 

 cause the laud is assessed at such a value that they cannot 

 take the time to produce a cover-crop, which might accom- 

 plish the same results. 



Touching Mr. Parmenter's question, I think that, using 

 sulphate of potash, as you are doing, and looking out for 

 lime, if experience indicates your soil has a tendency to 

 become solid, you w^U have no difficulty in producing your 

 potato crops, because I have so much confidence in the re- 

 cuperative value of the hay crop, — meaning by that a mixed 

 crop of timothy, redtop and clover ; and the clover will be 

 very prominent if you use fertilizers. 



Mr. Parmexter. What is your advice for a cover-crop 

 on our hill ? 



Professor Brooks. That is a difficult proposition, because 

 some one who looked at those magnificent fields reported 

 that they were green in October. You will have frost before 

 that time. I don't know of anything you can have there 

 which will give you much green material except rye. But 

 if you follow with oats, you must have rye, because the rye 

 will come up and mix with the oats. Rape is another ex- 

 tremely hardy crop. It is a hard problem for you, because 

 your potatoes occupy the ground so long, and then if you 



