Sodic soil reclamation using cottage cheese (acid) whey

Cottage cheese production in the United States yielded approximately 3 × 106 Mg of cottage cheese (acid) whey in 1991. Unmarketable whey is disposed of in sewage treatment facilities or on land. Environmental concerns and new laws make disposal even more costly and difficult. While much whey is applied to land for fertilizer or disposal purposes, acid whey has recently been used as a sodic soil amendment. The objectives of this research were to determine the effects of whey application on chemical properties and infiltration rates of sodic soils. Four treatments of acid whey (0, 25, 50, and 100 mm) were applied to Freedom silt loam (fine‐silty, mixed, mesic, Xerollic Calciorthids) in greenhouse lysimeters and to De‐clo loam (coarse‐loamy, mixed, mesic, Xerollic Calciorthids) in field basins. Accumulative sodium removal at 0.5 pore volumes of leachate was 1.0, 1.1, 1.2, and 1.7 mol for the 0‐, 25‐, 50‐, and 100‐mm lysimeter treatments, respectively. Whey applications lowered sodium adsorption ratio (SAR), exchangeable sodium percentage (ESP), and saturation paste pH in the lysimeter surface soil (0–150 mm) and field soil surface (10–150 mm). Saturated paste electrical conductivity was not significantly altered by whey application. In a greenhouse environment, 28 days after whey application, infiltration times in the 25‐, 50‐, and 100‐mm treatments were 320, 430, and 420% of the 0‐mm treatment, respectively. Infiltration times for field basin 25‐, 50‐, and 100‐mm whey treatments were 33, 31, and 26% of the 0‐mm treatment 53 days after whey application, respectively. Barley (Hordeum vulgare L. cv. Ludd) grain yield was 0.0, 0.0, 0.44, and 0.26 kg m‐2 and total dry matter yield was 0.54, 0.72, 2.0, and 1.4 kg m‐2 for the 0‐, 25‐, 50‐, and 100‐mm treatments, respectively. Excess salts and/or organic overloading in the 100‐mm treatment appeared to inhibit initial plant growth. Results indicate that acid whey is effective in reclaiming sodic soil by lowering ESP, SAR, and pH and by improving infiltration.