Submitted to: Land Reclamation and Mine Drainage International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 29, 1994
Publication Date: N/A
Interpretive Summary: The surfaces of soil disturbed by human activities are often degraded, with plant establishment and/or growth inhibited by excessive chemical additions or adverse physical conditions. A soil can exhibit a low pH, high salt content, or high concentrations of toxic metals. Soils may also be dense and compact at the surface, with openings or pores sufficiently small to hinder rainfall or irrigation water from entering them. Cheese whey, the liquid byproduct of cheese production, in some areas is a disposal problem but, if land applied, may help to open soil pores. In the spring and summer of 1993, whey was flood applied, at a rate of either 0, 202, 404, or 808 Mg/ha, to bermed plots of a Portneuf silt loam near Kimberly, ID. In August and September of 1993, a tension infiltrometer was used to measure unconfined (three-dimensional) infiltration rates into the bottom of irrigation furrows in each plot. Infiltration was measured with water held at a slight tension, to exclude water flow through the largest pores in the soil. Infiltration rates decreased as whey applications increased, probably because suspended solids or microbiological growth clogged pores at or near the soil surface. We concluded that cheese whey additions of 404 Mg/ha or less could be added to soil surfaces without adversely affecting soil hydraulic properties. This maximum annual whey loading rate for land applications during the summer can be used to safely dispose of whey on irrigated, winter wheat cropland in southern Idaho.
Technical Abstract: Whey, the liquid by-product of cheese production, significantly increases soil aggregate stability after incorporation. In mined land reclamation, whey can help reclaim sites with soils high in sodium or susceptible to erosion. However, whey effects on soil hydraulic properties are not known. This experiment determined whey addition effects on infiltration rates (at water potentials of -30 mm or less) and unsaturated hydraulic conductivities of surface soil horizons after a winter wheat (Triticum aestivum L.) growing season. An experiment was designed as a randomized complete block with three replications of four liquid whey application treatments, totaling either 0, 202, 404, or 808 Mg/ha. In the Fall of 1992 near Kimberly, ID, a field of Portneuf silt loam (Durixerollic Calciorthid) was leveled, subsoiled, then roller- harrowed twice. After planting 'Malcolm' wheat on September 15, we furrowed all plots then constructed a berm around each. Beginning on May 19, 1993, flooding was used to apply up to four applications of 202 Mg/ha of whey to the appropriate plots. In August and September, after wheat harvest, a tension infiltrometer was used to measure vadose zone, unsaturated flow characteristics in the bottom of undisturbed furrows, where much of the whey had infiltrated. Results indicated that infiltration rates at potentials of -60 and -150 mm decreased linearly as whey applications increased from 202 to 808 Mg/ha. At a water potential of -60 mm, whey additions up to 404 Mg/ha increased hydraulic conductivity, but higher rates decreased it. Whey additions of 404 Mg/ha or less did not greatly harm surface soil hydraulic properties.