J. A. Prescott 217 



tions reliance had to be placed on the temperatures observed at the 

 time of sampling, supplemented by the records of the Egyptian Ministry 

 of Public Works, which however refer to the subsoil only. A regular 

 series was started at Bahtini in l'.)i8 and records obtained for the surface 

 sojl, the thermometer bulb being placed at a depth of f 5 cm. The 

 following table gives the monthly means of soil temperatures observed 

 at Bahtim. 



Table I. 



Monlhly means of soil teiiiperaliires at a cle/il/i of IT) riii. Bahtim, 1917-18. 



Degrees centigrade. 



Oct. Nov. U(•<^ Jan. Feb. Mar. Apr. May Juno .July Aug. Sept. 



21 18 15-4 I2(> 14-2 18-3 23-5 25-8 28-2 29-6 281 2(il 



The biological processes in the soil should not then be normally 

 limited in Elgyjjt by temperature conditions, which at all times are 

 seen to be favourable. Factors limiting such processes as nitrification 

 must be looked for in other directions. 



Egyptian agricultural conditions. 



Agriculture in Egypt has always depended on the Nile water supply. 

 With the exception of certain coast lands where dry farming is possible 

 during the winter months and where the Bedouins raise a crop of barley, 

 the rainfall is quite insufficient to supply the recjuirements of even the 

 winter crops. The moisture content of the soil is therefore almost 

 entirely dependent on the conditions of irrigation. The most important 

 Egyptian crops are: Cotton, Maize, Wheat and Bersim (Egyptian 

 Clover). Of these cotton is the most important financially. It is sown 

 in February or March and occupies the ground until October and 

 November. It is essentially a summer crop. Wheat and Bersim are 

 winter crops; sown in October, November or December; they occupy 

 the land until May or June. It is possible, however, to get a single 

 cutting of Bersim just before the cotton crop. Maize is grown with 

 the surplus of water that is available in the time of the Nile flood and is 

 essentially a "Nili" crop. In Upper Egypt millet is grown as an early 

 summer and Nile flood crop and beans as an important winter crop 

 on the basin lands. In addition there are a number of special crops, 

 such as rice, sesame, lentils, onions, henna, which demand special 

 soil conditions and moreover find little place in the average farm rotation 

 of Lower Egypt. Cotton is such a valuable crop that it is grown as 

 frequently as possible, in most cases once in two years; under the best 



