174 BOARD OF AGRICULTURE. [Pub. Doc. 



Professor Brooks. I suppose all dry blood contains some 

 phosphoric acid, but I think this has been allowed for in 

 determining the amount to be used. 



I want to emphasize one other point ; the possibility of 

 making use of atmospheric nitrogen by the growth of clover. 

 There are in this series of a dozen or so of plots three plots 

 which for sixteen years have never received an ounce of 

 nitrogen in any form. It is a long time to go without this 

 which generally is so important in determining the amount 

 of the crop. The crop on that land this year was clover, — 

 common red clover, sown in July. A year ago this past 

 summer we cut two good crops on these plots which now for 

 sixteen years have not had an ounce of nitrogen supplied to 

 them in any way, shape or form. 



On these plots this year we got a clover crop practically 

 the same as on those plots that have every year been 

 manured heavily with barn-yard manure, or sulfate of am- 

 monia, or dry blood, or nitrate of soda. On all the plots 

 we have every year supplied potash and phosphate. They 

 were comparisons of the sources of nitrogen. On the plots 

 where we used no nitrogen we have this year got as good a 

 crop of clover as on those where we used nitrogen every 

 year. It is a fact of tremendous importance. You do not 

 make as much use of these recent discoveries of modern 

 science as you shovild. You ought to grow more clover, 

 and you ought to make it work for a living. If you put it 

 on land where there is plenty of nitrogen in the soil, it will 

 not work for a living. It will not take two steps to get 

 what it can get by taking one. If it can find nitrogen by 

 taking one step, it will use it and not take the second step ; 

 but if it takes the first step and does not find it, then it is 

 capable of taking another great long step into the air and 

 getting the nitrogen there. You ought to act upon that dis- 

 covery of modern science more than you do. 



Question. Would you buy no nitrogen whatever? 



Professor Brooks. Not absolutely that. There are con- 

 ditions where the farmer cannot aftbrd to depend on this 

 method of getting nitrogen. The gardener cannot always 

 atibrd to depend on it. I am not an unconditional advocate 



