EXPEKIMENTS ON CLOVKR-SOILS. 165 



Nos. 1 and 2 arr from a one-yi'ar-old crop of clover. The field 

 was a calcareous clay soil. It was somewhat hilly; or, perhaps, 

 what we here, iu Western New York, should call " rolliuir land." 

 The soil on the brow of the hill, "was very stony at a depth of 

 four inches, so that it could only with difficulty be excavated to 

 six ijiches, wlu-n the bare limt stone-rock made its aitpearance." 



A square yard was seleited on this siiallow soil, where the clover 

 was Ejood ; and tiie roots, air-ilried, weiglied at the rate of 7,7Uo lbs. 

 per acre, and contained 100 lbs. of nitrogen. A few yards disUince, 

 on the same soil, where the clover was bad, the acre of roots con- 

 tained only 31 ll)s. of nitro;;en per acre. 



S«> far, so iTOod. We can well understand this result. Chemistry 

 has little to do with it. Then- was a p)od stand of clover on the 

 one plot, and a poor i»ne on the other. And tiie conclusion to be 

 drawn from it is, that it is well worth our while to try to secure a 

 good catch of ch>ver. 



" But, suppose," .said the Doctor, " No. 2 had happened to hav<: 

 been pastured by sheep, and No. 1 allowed to go to seed, what 

 magi • there would have been in the above figures ! " 



Nos. 3 and 4 arc from the .same field, the second year. No. 4 is 

 from a sf[uare yard of thin clover on the brow of the hill, and 

 No. 3, from the rielnr, deeper land towards the bottom of the hill. 



There is very little dilTerence between them. The roots of thin 

 clover from the brow of tlic hill, ctintain five lbs. more nitrogen 

 per acre, than tiie roots on the deeper soil. 



If we can depend on the figures, we may conclude that on our 

 poor stony "knolls," the clover has larger and longer roots than 

 on the richer parts of the fi 'Id. We know that roots will run 

 long distances and great dejjths iu search of food and water. 



Nos. 5 and 6 are from a heavy crop of one-year-old clover. No. 

 5 was mown twice for hay, producing, in the two cuttings, over 

 four tons of liay per acre. No. 6 was in the same field, the only 

 difference being th-at the clover, instead of being cut the .second 

 time for hay, was allowed to stand a few weeks longer to ripen its 

 seed. You will see that the latter has more roots than the former. 



There are 24| lbs. of nitrogen per acre in the one case, and 51^ 

 lbs. in the other. IIow far tliis is due to difference in the condition 

 of the land, or to the difficulties in tlie way of getting out all the 

 roots from the square yard, is a matter of conjecture. 



Truth to tell, I have very little confidence in any of these figures. 

 It will be observed that I have put at the bottom of the table, the 

 result of an examination made in Germany. In this case, the nitro- 

 gen in the roots of an acre of clover, amounted to 191^ lbs. per 



