100 EGYPTIAN AGRICULTURE. 



formation of a layer of loose soil on the surface to prevent 

 extensive cracking. This is the important point to be 

 considered in fassing; the other effects, although beneficial, 

 can only be regarded as incidental. It is now necessary 

 to see the effect of covering the land with a loose layer of 

 soil. As soon as the crop completely shades the soil, 

 fassing is stopped. In fact, covering the land with a loose 

 layer of soil fassing has about the same effect as shading 

 it with plants. . The shade or loose layer of soil, prevents 

 the rapid outdrying of the upper layers of the soil, and 

 consequently prevents the rapid formation of a hard crust 

 and large cracks. It is necessary to clearly recognise that 

 the chief object of fassing is to cover the land with a loose 

 layer of soil which prevents the rapid out-drying of the 

 upper layers, and that consequently the hardening and 

 cracking of the soil is diminished. Preventing the out 

 drying of the soil results in a saving of soil water, but per se 

 this is of little importance except on unirrigated land. 

 Experiments at Ghizeh have shown that during summer, 

 land which is fassed retains four weeks after watering as 

 much moisture as unfassed land two weeks after watering, 

 and that three weeks after watering, the soil which has been 

 fassed contains about two and a half per cent more water 

 than the unfassed soil. A light fassing is more satisfactory 

 for this purpose than a deeper one, as the fassed soil whilst 

 preserving the moisture in the lower layers is itself dried 

 out. Indirectly, the result of light fassing is of the 

 greatest importance, because it permits of less irrigation 

 and the soil does not require to be so deluged A\ 7 ith water 

 us to make the solution of plant food in the soil too dilute. 



