66 BOARD OF AGRICULTURE. [Pub. Doc. 



heartily with what has been said in regard to the value of 

 humus. There is another point of importance in connection 

 with this question of clover sod as a crop to precede pota- 

 toes, and that is, the question of the extent to which the 

 turnine under of clover sod will enable us to manure the 

 crop at the least cost, on account of the fact that clover has 

 a large amount of nitrogen ; and evidence of this, of the 

 most striking character, is offered by the result of experi- 

 ments last season at the college. 



We had a field that we divided into eleven plots, of one- 

 tenth of an acre each. Three of these plots have not re- 

 ceived, either by farm manure or fertilizer, a supply of 

 nitrogen in any form in probably about fifteen years ; but 

 the other eight plots of the field have been manured with 

 something furnishing nitrogen, one field with- farmyard 

 manure, two of them with nitrate of soda, three with sul- 

 phate of ammonia and two with dried blood. All eleven 

 plots have received a liberal application of materials which 

 furnish phosphoric acid and potash. For the last few years 

 we have been following a general line of experiment, one 

 year to plant the whole field with something that has power 

 to gather nitrogen from the air, and the next year with 

 some other family that does not have power to get nitrogen 

 from the air. We wanted to find out to what extent having 

 a crop that would gather the nitrogen one year would make 

 it possible to have a good crop of some other kind, some 

 other family, the next year, on the plots where we did not 

 use any nitrogenous manure. That has been talked about a 

 great deal, you know, in the last few years. We stuck to 

 soy beans a good many years. We put in soy beans one 

 year, and the next } T ear grain, oats or something of that 

 sort, hoping to see, when we put in the grain, the oats 

 and the soy bean, in these plots that had not had ai^ nitro- 

 gen for a good while, that the crops would be coming up 

 approximately equal to those that had been given the nitro- 

 gen ; but we were disappointed every time. The average 

 crop on the three plots which did not receive the nitrogen 

 kept sinking lower and loAver, until, in 1898 I think it was, 

 the average of the three plots which had had no nitrogen 



