220 ANNUAL. REPORT OF THE Off. Doc. 



matter required. If you have a soil that is already rich in nitrogen, 

 you don't want them then. 



In Germany, near Berlin — Berlin is situated in a very sandy dis- 

 trict — tEe only thing they can grow is pine trees in that neighbor- 

 hood. They grow the yellow lupine. After the growth of the 

 lupine, it becomes very much richer in nitrogen. 



MR. NELSON: Mr. Chairman, I would like to ask the Professor 

 if the presence of potash in the soil is one of the principal things 

 in the growth of clover, that when we burn and clear new land in 

 this country, why it is that we have a condition there in which clover 

 will not catch on, or germinate, except in rare spots. 



PROF. HARSHBERGER: I think that is due to the leaf mould 

 that is still present in the soil. 



MR. NELSON: That is burned out by burning your clearing. 



PROF. HARSHBERGER: If you had a forest fully cleared, you 

 would find that leaf mould still present. It will go down a foot or a 

 foot and a half into the soil, and burning over the fop of the soil, 

 would not burn that out. You would perhaps burn the loose mater- 

 ial whereas this compact, black earth would go down a foot or two. 



MR. NELSON: That would hold good in swampy land, but not in 

 the conditions that I speak of. In our ordinary lands we don't have 

 any leaf mould, down more than three inches, that is, where the 

 ordinary burning has been done. 



PROF. HARSHBERGER: I would explain that in that case, by 

 saying that through all the ages, the organisms that exist, that are 

 in the soil of the forests, are more of the denitrifying kind; they 

 break down the leaf mould, and they are in larger number, and it 

 takes some time for the germs that may be present to increase 

 themselves in suflQcient number to do that. 



QUESTION. Might they not be destroyed by heat? 



PROF. HARSHBERGER: Yes; I am very glad for that sugges- 

 tion. 



PROF. WATTS: Mr. Chairman, I would like to say that I remem- 

 ber a case not very far away, I remember that they sowed clover on 

 a certain field and all that field was limed except a square block in 

 the center of the field, and the clover was a perfect success except 

 in the center where there was no lime applied, where it was a 

 failure. 



MR. NELSON: It is almost impossible in this country to get a 

 right good catch of clover before the third crop after land is newly 

 cleared, and I don't understand why unless it be the aeration by 

 cultivation, wherein the exhaustion of the acidity would come in. 



PROF. HARSHBERGER: Don't you apply lime to your soil? 



MR. NELSON: It is not generally applied to new land. I don't 

 know of any instance where we have applied lime to new land. 1 



