JiAT GUAXO IX iai(>J)KSIA. Ki'J 



Maxueial Trials — Bat Guaxo. 



The only reliable field trial Avitli a nitrog-enous bat guano 

 on red diorite soil was conducted as early as 1912 at the 

 Grwebi Experiment Station by Blackshaw,* who reported an 

 increased yield over the immanured plot of over two and 

 a quarter bags of maize per acre. 



The composition of the bat g'uano used in the trial was 

 as follows : — 



Nitrogen ... ... 5-28 per cent. 



Phosphoric oxide ... 423 ,, 



Potash ... ... 092 



When applied at the rate of 200 lbs. per acre, the result 

 was as follows : — 



Bat g'uano plot ... ... 1,712 lbs. 



Xil plot ... ... ... 1,248 ,, 



Increase due to manure ... 4G4 lbs. 



Whilst it is impossible to give any reliable returns of the 

 results of field trials on this season's maize crop from applica- 

 tions of nitrogenous bat guano, phosphatic bat guano or bat 

 g'uano supplemented by wood ashes on red diorite soils, there 

 are indications, however, of some interesting residts being 

 obtained. 



On a black vlei soil in the Makwiro district the increase 

 due to an application of a general guano fertiliser, Avhich 

 consisted of ajjproximately 70 per cent, of bat guano, was 

 two and three-quarter bags of maize. 



The guaranteed composition of the general guano 

 fertiliser used in the above trial was as follows: — 



Nitrogen ... ... 3'00 per cent. 



Phosphoric oxide : 



Water soluble ... ()'V2 



2 per cent, citric acid 



soluble ... 0-95 



Total ... 9-50 per cent. 



Potash ... ... 300 



When applied at the rate of 250 lbs. per acre, the 

 following results Avere obtained: — 



Guano plot ... ... 1,544 lbs. 



MI plot ... ... ... 1,002 ,, 



Increase due to manure ... 542 lbs. 



Bulletin No. 124. August. ld\2 .—D c pf . of Auric, Salishuir 



