J. A. Prbscott 229 



a plant needing a consideraljle amount of space, and at the present time 

 in Egypt there is considerable discussion concerning the spacing to be 

 adopted and the special cultivation to be given. In a manuring experi- 

 ment conducted at Bahtim in 1917 a system of cultivation on ridges 

 was adopted which later experience showed to have been inadvisable. 

 A number of nitrate determinations was made in this field and the 

 relatively high values obtained, particularly at a time when the plant 

 was most active in taking up nitrate, would indicate that the method 

 of planting adopted resulted in a waste of nitrate as far as the maize 

 crop was concerned. Some of the results are given in the following 

 Table XIII. Apparently both the nitrate added to the soil in the 

 fertiliser and that produced in the soil by biological activity is to an 

 appreciable extent dispersed in the soil out of the reach of the roots 

 of the maize plants. 



Table XIII. 



Atii<))i)ils of niirule found in the .loil of a maize field. 



Cultivdiion on ridges. 1917. 



Nitric nitrogen. 



Paits per million Moisture Manuring 



Date of dry soil % (lbs jier aere) 



Soil Subsoil 



(Jot. 1 16-7 11-4 lH-4 17-t) Unmanured 



14-7 11-8 l!l-:5 18-3 Nitrate of soda (333) applied in 



two dressings to crop 

 19-4 14-4 19-2 19-5 Nitrate of sodav(333) applied in 



one dressing before sowing 



17-9 18-0 18-5 18-7 Sulphate of ammonia (253) ap- 



plied in one dressing before 

 sowing 



A further series of determinations was made at the end of the season 

 in the case of an experiment on the spacing of the maize crop. The 

 results are given in Table XIV. 



Table XIV. 

 Amounts of nitrate and salts in the surface soil of maize plots. 

 Bahfi?n spacing experiments. 1917. End of season, Dec. 22. 



Nitric nitrogen. 

 Parts per million 

 Method of planting of dry soil 



Ridges. Thick sowing ... 31-5 



Ridges. Thin sowing ... 42-3 



Flat. Thick sowing ... 20-4 



Flat. Thin sowing ... 17-8 



Tops of ridges. Thick sowing ... OUIO 



Tops of ridges. Thin sowing ... (i47-7 



