86 REPORT OF THE AGRICULTURAL RESEARCH 



that there is very good reason for supposing that upon tnis 

 depends the ultimate prosperity of a country, the mineral 

 wealth of which not being commensurate with its agricul- 

 tural area and population debars it from the purchase of 

 adequate supplies of nitrogen from external sources. At 

 the present time the need of nitrogen in India is becoming 

 increasingly greater owing to the introduction of intensive 

 cultivation, although up till now the soils of this country 

 as a whole have been preserved from undue depletion by the 

 generally superficial and extensive nature of the cultiva- 

 tion employed, which has prevented large crops from being 

 taken off the land, alter the reduction of the original virgin 

 soil to the normal level of fertility by the growth of crops. 

 At the same time deportation of nitrogen in the form of 

 produce exported from areas in which it was grown has 

 not been excessive, and in the case of rice much fertiliza- 

 tion of the soil takes place by deposition of organic matter 

 carried down from jungle tracts by the irrigation water. 

 Nowadays, however, this state of affairs is being rapidly 

 altered owing to the expansion of Indian trade, which not 

 only transports foodstuffs from agricultural districts to 

 feed the increasingly large populations of cities, but 

 carries enormous quantities of produce out of the country, 

 including not only cereals, oilseeds and fibres, but bones 

 and hides which represent nitrogen collected from very 

 extensive areas of land. If now, in addition to this con- 

 stant drain upon the nitrogen resources of the soil, inten- 

 sive cultivation is introduced, meaning the more rapid 

 conversion of non-available plant food, especially nitrogen, 

 into the available condition, depletion will certainly follow, 

 differing in intensity from such a result in temperate 

 climate as the average soil temperature in India differs 

 from that in Europe, but in an even higher degree. This 

 difference due to temperature has been observed and mea- 

 sured in this laboratory as affecting ammonification, 

 nitrification, and the formation of carbon dioxide by oxi- 

 dation of the organic matter of the soil, and is not one of a 

 slightly higher degree, but may easily attain to an increase 



