2-6:* EGYPTIAN AGRICULT 



An application of 10 tons of coufri therefore would 

 mean the addition of 463 rotls of salt per feddan. 



The quantity of nitrogen found in an organic form in 

 coufri varies considerably, the higher percentages prob- 

 ably indicating that the mounds are of more recent origin 

 that those in which a practically complete decomposition 

 of the organic matter has taken place. An examination 

 of the 8 samples recently analysed will show that while 

 in some cases the amount of soluble nitrogen present 

 amounts to one fourth of the total nitrogen present, yet 

 in others almost the whole of the nitrogen present is in 

 a soluble form. 



It may be stated generally that only about 3% of the 

 transported material possesses any manurial value, and 

 that 97 % consists of more or less worthless matter. 



If we assume on an average that coufri contains 1 % 

 of nitrate of soda, then every ton of coufri added to the 

 soil means an application of 10 kilos of nitrate of soda. 

 An ordinary dressing of 10 tons therefore is equivalent 

 to the employment of 100 kilos of nitrate of soda. In 

 this dressing of 10 tons which is a common one for the 

 maize crop, the soil would perhaps receive 110 Ibs. of 

 phosphoric acid, and 200 Ibs. of potash. 



The percentages of these ingredients present are how- 

 ever very variable, and though the phosphoric acid and 

 potash form valuable additions to the soil, yet it is the 

 available nitrogen which exercises the greatest effect, and 

 this is seen by the fact that an application of coufri to a 

 quickly growing crop such as maize has a more immediate 

 effect than farm -yard manure, though the latter has a 



