Manures and Fertilizers. 33 



Dissolved Peruvian Guano has been treated with sulphuric 

 acid to fix the ammonia so that it will not escape into the air 

 and to make the insoluble phosphates available. It usually 

 contains about 6 per cent, nitrogen and 10 per cent, phos- 

 phoric acid. It is a very useful manure. 



Any of the above guanos may be used at the rate of 5 to 10 

 cwts. to the acre, or 2 to 4 ozs. to the square yard, worked into 

 the top soil during preparation for sowing or planting ; or 1 oz. 

 to the square yard may be used as a top dressing and watered 

 in about once every two weeks. 



Phosphatic Guano contains a large proportion of phosphates, 

 varying from 30 to 50 per cent., and a small proportion of 

 nitrogen, varying from 1 to 5 per cent. These guanos are a 

 very useful substitute for superphosphates, especially under 

 glass, where they are to be preferred because they are organic 

 and free from acid. 



Use about 4 cwts. per acre, or 1| ozs. to the square yard. 



Fish Guano is made from fish residues. It contains between 

 6 and 9 per cent, nitrogen and from 13 to 20 per cent, phos- 

 phoric acid. When it is to be used alone it should be spread 

 and turned in as soon as received, but if one of the potash salts 

 is mixed with it a much better balanced manure is obtained 

 that will keep better. It is fairly quick in action though 

 rather slower than Peruvian guano, and it feeds the plants 

 throughout the season. 



Apply a few weeks before sowing or planting at the rate of 

 5 to 10 cwts. per acre, or 2 to 4 ozs. per square yard. 



Meat Guano is prepared from slaughter-house refuse. It is 

 very variable in composition, some samples containing as high 

 as 12 per cent, nitrogen and 30 per cent, phosphates. A good 

 standard sample known as Fray Bentos Guano contains 7 per 

 cent, nitrogen and 30 per cent, phosphates. Like fish guano 

 this should be turned under at once, and not allowed to lie 

 about on the top of the soil or loss will result ; birds eat both 

 greedily. 



Use in a similar way to fish guano, varying the quantity 

 according to analysis. 



