Abstract

Hardsetting soils are characterized by horizons with unstable soil aggregates and their responses to organic inputs are not clear. A laboratory study was conducted to determine the effect of cattle manure on aggregate stability and strength in three hardsetting soils. Two treatments were included; cattle manure applied at 0 (control) and 20 mg/ha. Aggregate stability was measured as mean weight diameter and it increased by approximately 51%, because cattle manure prevented aggregates from slaking upon wetting and significantly increased the proportion of the water stable aggregates (>0.5 mm). Cattle manure also significantly lowered the soils’ strength as indicated by the lower penetration resistance, therefore cattle manure could be used to ameliorate the adverse physical properties in hardsetting soils.

Key words: Soil organic matter, mean weight diameter, soil penetration resistance, water stable aggregates, soil physical properties.