Self-Sealing of Earthen Liquid Manure Storage Ponds: II. Rate and Mechanism of Sealing
1985
Rowsell, J. G. | Miller, M. H. | Groenevelt, P. H.
A laboratory study was conducted to determine the degree and rate of sealing of the soil surface where liquid beef (Bos taurus) manure with solids content of 50 g kg⁻¹ was infiltrated into cores of a sandy loam, a loam, and a clay soil under hydraulic heads of 1 and 5 m. A second experiment explored the mechanism of sealing. The infiltration rate was expressed in the logarithmic form of the Kostiakov equation: log q = A + b log t where q = infiltration rate (m s⁻¹) and t = time (s). In this relation A represents the log of the initial infiltration rate (at 1.0 s) and b is the rate of change in rate with time on a logarithmic scale. The infiltration rate decreased rapidly with time and reached a value of 10⁻⁸ m s⁻¹ or less within 30 d on all soils at 1-m hydraulic head. This rate is considered to indicate an essentially impermeable system. At a 5-m head the infiltration rate reached 10⁻⁸ m s⁻¹ within 10 d on the clay soil but required periods > 30 d on the other two soils. A physical blocking of pores was the major mechanism of sealing. The rate of reduction of infiltration into the loam soil was similar for sterilized manure indicating that in this study biological activity was not a factor. Infiltration of a salt solution having similar cationic constituents as the manure remained constant over time indicating that dispersion of soil particles was not a factor.
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