50 PARA RUBBER. 



nitrogen, which they directly absorb from the atmosphere. It is 

 well to point out, however, that all soils do not contain the 

 necessary nitrogen-fixing bacteria, or they may be unable to 

 produce the desired results through having lost their activity. 

 Active bacteria may be introduced to soils by inoculating the 

 leguminous seeds to be planted with specially prepared cultures 

 of the organism. The whole process is fully described in Farmers' 

 Bulletin, No. 240, " Inoculation of Legumes," issued by the United 

 States Department of Agriculture. 



Although common salt was used as a crop fertiliser by the 

 Romans and the Chinese before the Christian era, it is compara- 

 tively little used for this purpose at the present day. It is a 

 powerful factor in breaking up soil and in rendering plant-food 

 constituents free, Applications of salt during periods of drought 

 are especially advantageous, as it absorbs moisture from the 

 atmosphere and aids the retention of moisture in the soil. It is 

 not generally known that salt is one of the principal ingredients 

 of various artificial manures. The amount to apply must, of 

 necessity, depend upon circumstances, but 600 Ibs. per acre 

 broad-casted may be considered an average application ; less is, 

 however, required on heavy soils, while a larger quantity would 

 probably prove more beneficial to light soils. 



Excessive applications of nitrogenous manures are not advis- 

 able for Heveas, as they tend to produce too rapid growth and 

 render the trees more susceptible to being broken by wind. 

 Different soils will obviously require fertilisers containing 

 different percentages of the various manurial elements. 



The following mixture has been found to yield good results, 

 but the proportion of the constituents may be regulated to suit 

 particular requirements : 



Basic slag 1,500 Ibs. 



Nitrate of soda - 2150 



Sulphate of potash 250 



This should be applied at the rate of about 300 Ibs. per acre, and 

 ploughed or harrowed in. 



Cattle manure is specially valuable for soil which is poor in 

 organic matter ; this should be applied at the rate of 8 tons 

 per acre, and, if circumstances permit, ploughed in. These soils 

 would also be materially improved by applications of vegetable 

 matter, such as leaves, grass, weeds, &c. 



