Miscellaneous. 



258 



[March, 1910. 



area of soil will result in the largest 

 employment of the bacteria which are 

 present for that purpose. 



It requires little consideration to reach 

 the conclusion that, as buried plants are 

 dependent upon the action of certain 

 bacteria for the production of useful 

 plant food from them, any means of 

 increasing the number of those bacteria 

 in the soil will make the efficiency of 

 such buried plants all the greater. This 

 theoretical consideration receives practi- 

 cal support from experiments which 

 plainly show that the admixture of 

 peu manure with the dressings before 

 ploughing in, even in proportions too 

 small for the manure to have any action, 

 of itself, in increasing the yield, has 

 hastened and directed the decay of the 

 green crop in such a way as to cause the 

 maximum benefit to be derived by the 

 one which succeeded it. 



The action of bacteria, then, is the 

 chief determining: factor in the changes, 

 eventually beneficial or otherwise, which 

 are undergone by green dressings. That 

 this action is of paramount importance 

 in the matter under review will be 

 rendered all the more evident in the 

 next article which, as has been stated, 

 will deal with the effect of the buried 

 plants on the soil. 



PROGRESS OF GREEN MANURING 

 FOR WET LANDS. 



By H. C. Sampson, 

 Deputy Director of Agriculture, 

 Southern Division- 



(From the Madras Agricultural Calen- 

 dar, March, 1910.) 

 A short note was written on this subject 

 in the 1908 Calendar, and the matter was 

 again referred to in the 1909 Calendar. 

 It is so important, however, that another 

 article on the same subject will not come 

 amiss. 



At first sight the fact that a crop is 

 grown on the wet land and ploughed 

 in, may, to any one who has not tried 

 it, seem a waste of time and money, 

 because nothing except a seed sown is 

 put into the land. In reality this is 

 not so, all the green manure crops 

 referred to below belong to the family 

 of plants which have the power of col- 

 lecting nitrogen from the air, the same 

 family in fact as Kolingi, Avari, Pongam, 

 all of which are selected by ryots 

 especially valuable for green manure. 

 Farmers have found out by experience 

 that such leaves as these are the best 

 for wet lands, but investigation has 

 shown the reason, namely, that these 



plants contain more nitrogen than 

 others, and that such plants and only 

 plants of this family are able to make 

 use of the nitrogen which is in the air. 

 Nitrogen is the most valuable ingredient 

 of all manures, and if nitrogen was not 

 present in, for instance, a poonac, the 

 latter if applied to a crop would not 

 give it that healthy dark green appear- 

 ance which always follows an appli- 

 cation of poonac on a well-drained soil. 

 Hence, though the farmer, when he 

 sows a green manure crop does not put- 

 any manure into the ground, such plants 

 as are described below can collect nitro- 

 gen from the air. This is not all, for, ' 

 except the ash of the plant, all the 

 vegetable matter, which, when ploughed 

 in, rots and improves the texture of 

 the soil, is also obtained by the plant 

 from the air. Hence, growing green 

 manure crops is most profitable, espe- 

 cially if village ashes are also applied 

 at the time of puddling. 



Sunnhemp, indigo, wild indigo, cow- 

 gram, groundnuts and daincha (Sesbania 

 aculeata) are all plants which can be 

 mown under certain conditions for 

 green manuring, 



Sunnhemp.— This is perhaps grown 

 more largely than any other green 

 manure crop. Every year large areas 

 are grown in the Kistna and Godavari 

 Deltas. The seed is sown just before the 

 paddy is harvested and the crop is cut 

 when 4-5 feet high. It is cut at about a 

 foot from the ground and the stubble 

 is allowed to remain and grow again. 

 The tops are dried and make excellent 

 fodder. The sunnhemp, however, on 

 account of its extraordinarily rapid 

 growth can be utilised in many places 

 and under other conditions. In six 

 weeks the crop will attain a height of 

 3 to 4 feet if the ground is moist. Thus, 

 on wet land, where water is always 

 available, or on wet lands where the seed 

 beds are not prepared until water is 

 available, or again on wet lands under 

 tanks where the latter have been filled 

 by early rains and the season for trans- 

 planting has not arrived, under all these 

 conditions sunnhemp can be grown. On 

 the Tanjore delta excellent crops can be 

 raised after the receipt of water in the 

 channels in time to plough in before the 

 seedlings are ready. Again, the heavy 

 summer rains which last year fell in 

 many districts filled many tanks which 

 did not expect their supply till June- 

 July. On the Coimbatore Agricultural 

 Station advantage was taken of this 

 water to grow an excellent crop of sunn- 

 hemp, which was ready to be ploughed 

 in by the time the seedlings were ready 

 to transplant. On the West Coast also 



