THE SOUTHERN PLANTER. 



Iff 



sulphate of ammonia. And yet Liebig says 

 we may "tvith certainty assume" that if Mr. 

 Lawes had accidentally manured his field with 

 4, 5, or 6 cwt. of ammonia salts, he would 

 have obtained no greater increase than from 

 3£ cwt. Now, as we have shown, he did ap- 

 ply — not W accidentally," however — more than 

 4, 5, or 6 cwt., and obtained a proportional 

 increase. We may "with certainty assume," 

 therefore, that Liebig has made a great mistake 

 on this point. 



The objections which Prof. Liebig has made 

 to Mr. Lawes' experiments, are so utterly 

 without foundation in jact, that nothing but 

 his great reputation renders them worthy of 

 notice. 



Our remarks are already far too extended, 

 but we have just received the last Journal of 

 the Royal Agricultural Society of England 

 (Vol. XVI, Part 1,) in which we find a "Re- 

 port to the Earl of Leicester, on experiments 

 conducted by Mr. Keary, on the Growth of 

 Wheat, at Holkham Park Farm, Norfolk, by 

 J. B. Lawes," which affords much light on the 

 subject under discussion. It is a report of 

 an experiment in growing wheat four years in 

 succession, by the use of the various organic 

 and inorganic elements of plants, somewhat 

 similar to that on the Rothanistcad farm, with 

 this important difference : The soil at lloth- 

 amstead is a heavy wheat soil; this in Nor- 

 folk is "a light, thin, and rather shallow brown 

 sand loam," which, previous to the introduc- 

 tion of turnipculture by the late Wm. Coke, 

 on this very farm, was considered incapable of 

 growing wheat. A greater contrast than be- 

 tween it and the Rotha instead soil could 

 scarcely be imagined. And yet the results are 

 the same. 



The same manures were applied to the same 

 acre each year, and the whole of the produce 

 removed. We have not space for the details, 

 but the following are the aggregate results of 

 the four years : 



The first acre, on which no manure at all, 

 was used, produced in four years, 93£ bushels, 

 or an average of a little over 23 \ bushels per 

 acre each year. 



The second acre, dressed each year with 300 

 lbs. sulphate of potash, 200 ibs, sulphate of 

 soda, 1 00 lbs sulphate of magnesia, and 350 

 Jbs. of superphosphate of lime (200 lbs. calcined 

 -bone-dust and 150 lbs. sulphuric acid,) pro- 

 duced, in four years, 92 bushels, or an average 

 of 23 bushels per acre each year. 



The third acre, dressed each year with 200 

 lbs. each of sulphate and muriate of ammonia, 

 applied in the autumn, produced, in four years, 



125^ bushels, or a little over 31£ bushels per 

 acre each year. 



On the fourth acre the same quantity of 

 ammonia applied as a top dressing in the 

 spring, gave in four years, 124 bushels, or an, 

 average of 3 1 bushels per acre each year. 



On the fifth acre, the same quantity of miiw- 

 ral manures (sulphates of potash, soda, a* A 

 magnesia, and superphosphate of lime,) as ap- 

 plied on the second acre, and .200 lbs. each «f 

 sulphate and muriate of ammonia, produoed, 

 in four years, 145 bushels, or an average «£ 

 36£ bushels per acre each year. 



The sixth acre, dressed with a ton of rap©* 

 cake (2000 lbs.) each year, produoed, in f<K* 

 years, 147£ bushels, or an average of 3Gf 

 bushels per acre each year. 



The seventh acre, dressed each year with 14 

 tons of farm-yard dung, produced, in four 

 years, 135£ bushels, or an average of 33-f 

 bushels per acre each year. 



Without manure the soil produced 23 bushels 

 of wheat per acre; the addition of mineral 

 manures alone gave no increase; ammonia, 

 alone gave an increase of 8 bushels ; ammonia 

 and mnerals, an increase of 13 bushels. From 

 this it is evident that the amount of minerals; 

 annually available in this naturally poor eoil^ 

 were considerably in excess of the quantity of 

 ammonia annually available from natural 

 sources ; in fact, that there were minerals suf- 

 ficient for 31 bushels, while there was only 

 enough ammonia for 23 bushels. But the 

 quantity of minerals annually rendered availa- 

 ble by the disintegration of the soil, &c., al- 

 though considerably in excess of the natural 

 supply of ammonia, was not sufficient for more 

 than an annual crop of wheat of 3 1 bushels 

 per acre. To obtain more than this, it was 

 necessary to supply, in addition to ammonia, 

 a greater or less quantity of the mineral ele- 

 ments of plants. When these were supplied, 

 the produce rose to 36 bushels. 



The fact that, under these circumstances the 

 mineral manures were taken up by the plant% 

 and gave an increased crop, is conclusive evi- 

 dence that they were in an available condition, 

 and that their failure, when used alone, m 

 these and in the Rothamstead experiments,, 

 is attributable to a lack of ammonia in the soil, 

 and not to t&eir being in an unsuitable form 

 or improper proportion. It demonstrates that 

 although a soil abounds in the mineral ele- 

 ments of plants in an available condition, suf- 

 ficient ammonia or nitrogen can not be ob- 

 tained from natural sources for a full wheat 

 crop. It is additional proof, if such were 

 needed, that ammonia does not act solely, or 



