CLOVEK AS A PREPARATORY CROP EOR WHEAT. 481 



Nitrogen in 1st 6 inches of soil 4725 lbs. 



Nitrogen in roots 5I5 



Nitrogen in 2d 6 inches of soil 3350 



Total amount of nitrogen per acre in 12 inches of soil 8126^ 



Equal to ammonia 9867 



or in round numbers, 3 tons and 12| cwts. of nitrogen per acre, 

 equal to 4 tons and 8 cwts. of ammonia. 



This is a very much larger amount of nitrogen than occurred 

 in the other soil, and shows plainly that the total amount of nitro- 

 gen accumulates, especially in the surface soil, when clover is 

 grown for seeds ; thus explaining intelligibly, as it appears to me, 

 why wheat, as stated by many practical men, succeeds better on 

 land where clover is grown for seed than where it is mown for hay. 



All the three layers of the soil after clover seed are richer in 

 nitrogen than the same sections of the soil where the clover was 

 twice mown, as will be seen by the following comparative state- 

 ment of results. 



This difference in the amount of accumulated nitrogen in clover 

 land appears still more strikingly on comparing the total amounts 

 of nitrogen per acre in the different sections of the two portions of 

 the 11-acre fields: 



Per centage of nitrogen per acre : 



1st 6 inches. 



lbs. 

 . ^ 3350 .. 



*I. In soil, clover twice mown 



tl. In soil, clover once mown and seeded S- 



afterwards j 4725 . 



Equal to ammonia : 



*I. Clover twice mown ) 4050 . 



til. Clover seeded 5 6725 . 



I. Nitrogen in roots of clover twice mown. . . f 24J 

 II. Nitrogen in clover, once mown and grown > 



for seed afterwards ) 51i 



1. Weight of dry roots per acre from Soil I. > 1493^ 



II. M'^eight of dry roots per acre from Soil 11. 5 3622 

 *Total amount of nitrogen in 1 acre 12 inches^ 



deep of Soil 1 1 5249 J 



fTotal amount of nitrogen in 1 acre 12 inches f 



deep of Soil II J 8126^ 



*Equal to ammonia i 6374^ 



tEqual to ammonia 5 9867 



31 



2d 6 inches. 



lbs. 

 .. 1875 .. . 



3350 



2275 

 4050 



3d 6 inches. 



lbs. 

 .. 1325 



2225 



1600 

 2700 



