HOWARD AND HOWARD BS 
tints which, according to Hilgard,! indicate a lack of aeration in consequence 
of imperfect drainage. The indigo soils easily run together on the surface 
after moderate rain forming a well-defined crust, known to the cultivator as 
the papri. After long continued heavy rain, this crust may become several 
inches thick, the porosity of which is not recovered until the land dries and 
is cultivated. An excessive rainfall besides producing these impermeable 
crusts, also leads to the waterlogging of the pore spaces of the upper soil 
(probably due to deflocculation of the clay particles) for comparatively long 
periods.? 
Rainfall. The average annual rainfall is in the neighbourhood of 50 
inches, most of which falls during the period May to September (Table 1). 
1 Hilgard, “Soils,” 1906, p. 45. . 
2 Agr. Jour. of India, Special Indian Science Congress Number, 1919, p. 381. 
