VALUE OF MANURES 



INDIGOFERA 



Cultivation 



t IMII is the refuse of the indigo plant termed sect, procured from the factory, am. 

 Artificial manures have nuule little headway, and even with the simpler 

 fertilisers, such as lime, gypsum and nitre, there is uncertainty as to their 

 eilicacv. In this connection attention should be given to the result* 



ied by Mr. C. Rawson, summarised in his final report to the Bihar 

 Indigo Planters' Association, published in 1904. As a rule indigo soils 



'Mind deficient in available phosphoric acid, and responded remunera- 

 tively to treatment with superphosphate, bonemeal or other phosphatic suprphcphu. 

 manures. Nitrogenous manures were generally found useful when applied 

 almii,' with phosphates. Dr. Hancock, working at Dalsing Serai under 

 M- Bernard Coventry in 1901 (Rept. Indigo Improv. Syndicate, 1901), 

 arrived at the same conclusions. The value as manure of the refuse plant 



A as also investigated by Rawson, with the result that he came 

 to believe that in many cases it was as valuable as the indigo produced 

 l>\- the factory. Mr. W. Popplewell Bloxam next took up the inquiry into 

 the subject of indigo improvement by scientific manuring. In his report 

 to t ho Government of Bengal, 1905, on the work carried out by Leake and 

 himself at Dalsing Serai (in 190&-4), he summarises his experiments and 

 results. The chief feature of these may be characterised as the supply of 

 various carbonaceous materials to indigo soils with the view of ascer- c*rbonMx 

 taining their effect on the growth of the nodule bacteria. The period of M*** 1 * 1 * 

 Bloxam's experiments was, however, too short to allow of any very definite 

 conclusions. [C/. Voelcker, Improv. Ind. Agri.,1833, 106, 112, 259, 260-1 ; 

 Rept. Cawnpore Exper. Farm \ Bergtheil, Ace. Sc. Invest, on Indigo, in 

 Rept. Dept. Land Rec. and Agri. Beng., 1905, vii.-ix.] 



Dangers to the Crop- " Under favourable conditions the young Dangers. 

 plant will appear above the surface on the seventh to the tenth day, from 

 which time onwards it is exposed to many vicissitudes. It is no uncommon 

 occurrence to find the destruction of the crop to be caused by a shower of 

 rain. It has already been explained that the young plant is dependent 

 on what may be termed ' bottom ' moisture for its early growth, and Effect of 

 on the condition of the soil which makes this available. The ' com- * tatur8< 

 pacting ' of the surface soil leaves a loose, dry layer on the surface which 

 acts to a certain degree as a check on evaporation. The effect of rain is 

 to do away with this dry layer and to establish a complete capillary system 

 to the absolute surface. The ultimate result is a rapid decrease in the 

 moisture of the superficial soil, which may ultimately be reduced to below surf** era*, 

 the limit at which life can be supported. Under these circumstances 

 the crust must be broken even at the cost of destroying half the crop. 

 This is usually effected by the use of a light rake, or, in the case of a very 

 light crust, by brushwood drawn over the surface. A prolonged spell of 

 hot west winds, such as are common during April-May, in spite of the 

 precautions taken to conserve the moisture, reduces this to below the 

 needful minimum, and in this way the greater part of the crop may be lost." 



" As regards pests little can be said. The larvae of numerous LEPIDOP- Pests. 

 TERA feed on the indigo plant, but in only one case are the ravages sufficient 

 to cause serious damage. Under favourable conditions the larvae of 

 .1 (/rot is sciictis appear shortly after the young plant has broken through orubt. 

 the soil, and before what is known as the ' 7-leaf ' stage is reached. Plants 

 attacked will be entirely stripped of their leaves, and a second sowing may 

 be necessary. In bad seasons this may also happen, and necessitate a 

 third sowing. It seems probable that the ravages of this pest are only 



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