Scientific Agriculture. 



376 



[Jwne 1907. 



The thornless "Dadap" (Erythrina lithosperma) possesses the advantages 

 of being easily propagated from cuttings ; and in five mouths as much as 4,000 lb. 

 per acre of fresh green material may be turned into the soil, whilst in twelve 

 months 15,000 lb, may be available. The leaves and twigs which are lopped off 

 contain 0*85 per cent, of nitrogen in the fresh state, and the equivalent of at least 

 2,100 lb. of castor cake per acre per year may thus be grown. 



The advantages of the use of " Dadap " are (1) the ground need not be forked 

 before planting as is necessary with those plants such as Crotalaria striata, ground 

 nuts, etc., which are propagated from seed ; (2) weeding is simplified as it is impos- 

 sible to mistake the " Dadap " cuttings for weeds, whilst young Crotalaria plants 

 might be thus mistaken ; (3) the arborescent form is convenient in association with 

 some crops on account of the shade it affords ; (4) the large roots tend to split up the 

 hardened foot-trodden soil. 



The chief disadvantages of the use of " Dadap " are that (1) the force of the 

 rain is not much checked ; (2) the larger leaves collect some water and lead to a 

 drip on the soil beneath ; (3) less protection is afforded to the soil when Crotalaria 

 is planted. 



Of the other plants tried, cowpeas (Vigna Catiang), although suitable for 

 planting with some crops, have the disadvantage of twining round the stems of the 

 main crop. Ground nuts (Arachis hypogoea) are also of value under special con- 

 ditions, and the Pondicherry variety, which yields a large amount of leaf and stem 

 with but little fruit, seems specially useful as a green manure. Albizzia moluccana 

 is somewhat difficult to establish as it can only be propagated from stumps or 

 young plants, which have been specially grown ; it is, however, a very rapid grower 

 and the cuttings are rich in nitrogen. 



The influence of various fertilising materials upon nodule formation has 

 also been investigated by means of pan experiments, and the results obtained are 

 not in harmony with those of the United States Department of Agriculture ; thus 

 leguminous plants manured with such nighly nitrogenous materials as sodium 

 nitrate, ammonium phosphate, and castor cake showed very slight differences from 

 unmanured plants in the number of root nodules formed.— Bulletin of the Imperial 

 Institute. 



