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In fact I can hardly say that I believe in the theory of a garden 



being allowed to become weedy for the sake of the green manure 



these weeds supply. When a miscellaneous collection of plants like 



the usual crop of weeds are allowed to grow in a garden, some may be 



valuable, some may be neither valuable nor harmful, and some may 



very likely be distinctly injurious inasmuch as they may form 



refuges for the pests and blights of the tea, and further they, at 



some seasons, abstract water from the soil that the plants need. 



Perhaps there is not much objection to a few weeds in September 



and October, but even then, as first suggested to me by 



Mr. Henderson of Salonah, it is surely far better to have a definite 



crop known to be valuable on the ground than a mixture of useless, 



and it may be, injurious plants. 



It will, I think, be found that the plants which answer most of the 

 conditions laid down only belong to two classes : the mustards on 

 the one hand, and leguminous plants on the other. The former 

 answer every condition admirably, except that of returning more to 

 the land than they have extracted, but the latter answer this as well 

 as all the others. This condition does not exclude the use of the 

 mustards in Assam for green manuring though they have been hardly 

 found to be profitable in other countries. Land however which grows 

 leguminous crops too often is apt to become " sick " of them, and 

 under these circumstances mustard might replace them with great 

 advantage. 



LEGUMINOUS PLANTS AS GREEN MANURES. 



To the leguminous crops, however, one has to turn to supply the 

 really most valuable green manures, and this because they return to 

 the soil more Nitrogen than they take from it, owing to the growth 

 of a bacterium on the root which fixes the Nitrogen of the air and 

 passes it on to the plant, a bacterium which seems exclusively to 

 grow on the rodts of this order of plants, on whose roots it forms 

 nodules nearly always visible to the naked eye. 



The only plant of this order hitherto used to any great 

 extent in Assam is Mati Kalai (Phaseolus aconitifohus] and its 

 growth has been very successful. It has been most systematically 

 tried perhaps by Mr. Hutchison of Dooria, Golaghat, and in a 

 recent letter to me on this subject he says : 



I have sown kalai in various months with varied success, as good growth is much 

 dependent on moisture, and not too hot and dry a time. April is a good month for sowing 



