Submitted to: Arid Soil Research And Rehabilitation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 14, 1991
Publication Date: N/A
Interpretive Summary: Sodic soils are those soils that have high sodium to calcium plus magnesium ratios and low total soluble salt concentrations. These soils have poor physical properties which cause low water and air entry and often form hard surface crusts. Usually they cannot be economically reclaimed. However, adding whey (a waste product) from the phosphoric acid method of cottage cheese manufacturing, removed the sodium and its harmful effects from otherwise productive soils while also adding nitrogen, phosphorus and potassium fertilizer. The main drawback to this reclamation method is the transportation cost of the watery whey material. It takes 50,000 to 100,000 gallons to reclaim an acre of sodic soil (4-inch depth).
Technical Abstract: Sodic soil reclamation requires replacing exchangeable Na+ with Ca2+ and leaching the excess Na+ from the soil. Cottage cheese whey has an electrical conductivity (EC) of 6-10 dS m-1, pH values of 4.2 or less, low sodium adsorption ratios (SAR), and contains 40-50 g kg-1 of readily decomposable organic matter. These whey characteristics should all be beneficial in reclaiming sodic soils. This study was conducted to determine the effects of cottage cheese whey on the chemical and physical properties of a sodic soil (SAR=16.3, ECe=3.8, and pH 8.3). Cottage cheese whey was applied to 300 mm deep sodic soil columns at 0-, 20-, 40-, and 80-mm rates followed by 80, 60, 40, and 0 mm of distilled water, respectively. The columns were then incubated at 10 degrees C for 21 days, and then leached until 96 mm (0.60 pore volumes) of leachate was collected. All whey applications lowered the soil pH, SAR, and exchangeable sodium percentage (ESP) in both the upper and lower 150-mm depth increments. Aggregate stability in the surface 150-mm-depth increment increased from 11% in the water-leached soil to 22% in the 80 mm whey-treated soil. The results of this study suggest that cottage cheese whey can be used as an effective sodic soil amendment.