Scientific Agriculture. 



434 



[May, 1912. 



almost all that has been written regard- 

 ing the latter applies to this substance 

 also. It must, however, be remembered 

 that unlike bone super it contains no 

 nitrogen. Another phosphatic manure is 

 basic slag, and probably with a develop- 

 ment of the steel trade in this country, 

 it may become readily accessible to the 

 cultivator. At present, however, it may 

 be left out of account. 



Lately, two artificial manures have 

 been introduced in Southern India, name- 

 ly, Calcium nitrate and Cyanamide, and 

 it is probable that in the near future they 

 will be manufactured in this country. 

 Of the two. so far as paddy cultivation 

 is concerned, calcium nitrate is of little 

 use, but Cyanamide may possibly find 

 an application as it yields ammonia in 

 the soil, and in consequence could be 

 used to enrich the nitrogen content of 

 low grade poonacs, etc. Experiments 

 are now being carried out with this 

 substance at Coimbatore. 



All of these artificial manures, it must 

 be pointed out, do not fulfil the first 

 condition laid down with regard to 

 paddy manuring, i.e., to supply organic 

 matter to the soil, and consequently 

 although they can be used either alone 

 or in suitable admixture with one 

 another, the best results are obtained 

 when they are used in conjunction with 

 bulky organic manures. An exception 

 may, however, often be made in the ease 

 of superphosphates, for when the soil is 

 poor in phosphoric acid, a dressing of 

 the substance has often yielded remark- 

 ably good crops, but even here it will be 

 necessary sooner or later to supply 

 organic matter if the enchanced rate of 

 cropping is to be maintained. 



In concluding this section it must be 

 stated that many of the yields which 

 have been quoted were not obtained the 

 first year after applying the various 

 manures. In reality the yields obtained 

 have gradually increased with each 

 annual application of manure, so that a 

 permanent enrichment of the soil has 

 taken place. Thus, when green-manure 

 was first applied to a plot of paddy land 

 on the Central Farm, a yield of only 



2,400 lbs. of addy per acre was obtained, 

 but the next season yielded 3,500 lbs., and 

 now after being annually manured for 

 four years the yield is 3,900 lbs. Most of 

 the other experimental plots show the 

 same increaping outturn, and in one case 

 the yield now obtained is 4,500 lbs This 

 result is most important as showing the 

 possibility of producing a greatly in- 

 creased fertility in paddy soils, but to 

 obtain such results careful and system- 

 atic manuring is required. Spasmodic 

 manuring at intervals of a series of 

 seasons cannot bring this about and will 

 only lead to a comparatively insignificant 

 increase in the average fertility of the 

 soil. 



THE SUBSTITUTION OP BASES IN 

 PLANT NUTRITION. 



From the Agricultural Neivs, Vol. X., 

 No. 252. December 23, 1911.) 



This interesting subject has received 

 attention in a recently issued Journal, 

 in the shape of a translation of a paper 

 read before La Societe Centrale d' Agri- 

 culture de' Belgique, and appearing in 

 the number of the journal of that Society 

 for May 7, 1911. Investigations in re- 

 gard to the matter have been carried 

 out over a period of many years, and 

 it will be well at the present time to 

 draw attention to some of the more 

 important results that have been ob- 

 tained, employing for the purpose the 

 information presented in the paper just 

 mentioned. 



The British Association for the Ad- 

 vancement of Science, at the meeting 

 in Liverpool in 1837, requested that a 

 review should be made by Liebig and 

 Dumas of the state of the knowledge, 

 at the time, of organic chemistry. The 

 result was the preparation, by Liebig, 

 of his Treatise on Organic Chemistry, 

 in relation to agriculture and physiology. 



It was pointed out in the memoir 

 that the bases most usually met with 

 in plants are potash, soda, lime and 

 magnesia, and that these are capable 

 of replacing one another, in chemical 

 compounds, in amounts that are con- 



