Soil Crack Morphology and Soil Salinity1

This study considers the effects of soil salinity on soil crack morphology, soil bulk density, and water content in the field where soil cracking is not affected by the plant canopy or plant water extraction. Field measurements along transects of three different salinity treatments were taken 3, 6, 9, and 12 days after irrigation and 1 day before the next irrigation. Measurements of crack island width, crack width, and depth along a transect were taken from 37 (0.8 × 1.2 m) rectangular areas at 5-m intervals along the border. Typically, as salinity increased, soil crack width, island width, % cracked area, and crack volume tended to increase, whereas crack depth decreased. Bulk density values measured at borders irrigated with salty water tended to increase faster, as water content decreased, than at borders irrigated with good quality water. Such behavior can be attributed to a lack of large pores on salt-affected soils, possibly occluded by swelling and dispersion mechanisms.