before planting, it is usually much less favourable for the tea seed- 

 lings than before. The fact has been brought to my notice by 

 many planters, that land not planted rapidly deteriorates after 

 clearing, and that it should be planted up at once. The explanation 

 is undoubtedly that given above, and the only means of avoiding 

 the deterioration is by planting a crop on all such cleared land, 

 keeping a crop on it as far as possible until the time for putting in 

 the tea seedlings, and hoeing this in before actually planting. 



NITROGEN SUPPLIED BY RAIN. 



To counterbalance these sources of loss of nitrogen there are two 

 or three sources of gain. The rain brings a considerable amount of 

 nitrates and salts of ammonia, all of which contain nitrogen, but this 

 only amounts to a fraction* of that required by the plant, and as 

 much of it comes when the water almost runs direct through the soil 

 into the drains, much less than the apparent amount is useful to the 

 plant. In fact, I think one may neglect this source of nitrogen in 

 determining the means of supplying this material for the tea plant. 



FIXATION OF NITROGEN BY THE SOIL AND BY PLANTS. 

 Various observers,*)- however, have found that the soil alone with- 

 out any plant growth has the power of fixing nitrogen, also by means 

 of soil microbes. The mechanism of this is not very well under- 

 stood, but it is probable that under suitable circumstances it may 

 have a very great influence in preventing the absolute exhaustion of 

 land. Further, plants of the order Leguminosae, of which Mati Kalai 

 (Phaseolus aconitifolius), Sensitive Plant (Mimosa pudica) and Clover 

 ( Trifolium spp.} may be taken as the types, are also very valuable as 

 a means of increasing the store of nitrogen in the soil. And 

 beyond this there are certain low green slimy " algae " which, 

 growing on the surface of the land, lead to the fixation of the con- 

 stituent in question. Exactly how much value, under normal condi- 

 tions, may be put on these various agencies has never been investi- 

 gated in the tropics, but would be a most interesting subject were 

 facilities for such work to be obtained. 



EFFECT OF NITROGEN, &C., ON THE QUALITY OF TEA. 



Nitrogen and organic matter are the most essential constituents 

 in the soil for luxuriant growth. Ho\v does their presence or absence 



* Mr. Bamber found the total nitrogen in the rainfall of Colombo to be 7*628 Ibs. 

 per annum per acre. 



t Winogradsky ; Berthelot and Andre. 



