170 J;AT GIA.XO 1^' KlIODKSIA. 



COMl'OUIS-]) I'Eirj'ILlSEKS . 



Bat guano, from the ,staiidi)()iiit of the agiicultuiist, is 

 a poorly-bahinced manure, yet in many instances the mere 

 addition of sulphate of potash wouhl make an excellent 

 feitilisei-. In certain other cases, the addition of nitrate of 

 soda, superphosphate and sulphate of potash for providing" 

 some readily available plant food, Avould result in an ideal 

 fertiliser suitable for most crops. 



Nitrogenous l)at guano, in conjunction Avith wood ashes, 

 should prove a suitable fertiliser for maize and tobacco. 

 Blacksliaw' has recommended the following dressing i)er acre 

 for maize and tobacco : — 



Maize: GOO lbs. Mood ash; 150 lbs. nitrogenous bat guano 

 (4 per cent, of nitrogen). 



Tobacco: 1.0(10 to 2,000 lbs. of wood ash; MOO lbs. 

 nitrogenous bat guano (4 per cent, of nitrogen). 



Wood ash should be broadcasted over the land after the 

 first i)loughing and thoroughly harrowed in, and the bat 

 guano applied broadcasted just before planting and lightly 

 harrowed in. Bat guano and wood ash should on no account 

 be mixed before application, as loss of nitrogen would occur. 



Gexek AL Conclusions. 



The bat guano in many of the caves is of considerable 

 value, and, Avhen made up to aj^proved formula Avith approved 

 ingredients and sold at a jjrice Avliich is relatively cheajier 

 than imported or other fertilisers, should be in great demand. 



It is A-ery doubtful if the bulk of the deposits Avould 

 bear the cost of treatment Avith sulphuric acid for converting 

 ammoniuni carbonate into non-A'olatile ammonium sulphate, 

 and for rendering the plios])horic oxide soluble iu Avater, as 

 in the majority of cases the pliosphoric oxide is too Ioav. 



Purchasers of bat guano should insist on being supplied 

 with a guaranteed analysis, oAAing to the material Aarving so 

 much in composition. 



* G. N. Blackshaw (Oct., 1919)— Fertilisers for maize and ti)l)aeco. 

 -I'hodcsio II Aijiic. ■Journal, pp. 4o6-4o9. 



