From Factory to Field: Effects of a Novel Soil Amendment Derived From Cheese Production on Wheat and Corn Production

Abstract

To meet the nutritional demands of a rapidly growing population in the face of increasing climate variability, innovative tools are needed to rapidly regenerate soil health in agricultural systems. Using food wastes to improve soil health presents a viable opportunity to improve soils and efficiently manage waste. In a previous laboratory study, we found that potassium lactobionate, a byproduct of cheese production, greatly enhanced soil water holding capacity and nutrient availability. To further explore its potential as a soil amendment, we conducted agronomic trials in winter wheat and corn at the USDA-ARS Central Great Plains Research Station in Akron, Colorado. We evaluated lactobionate for potential improvements in key soil health indices, focusing on soil moisture, carbon, and nitrate. Lactobionate was applied at 5 rates and either as broadcast or surface banding depending on the crop, and soil samples were collected from 0 to 5 cm and 5 to 15 cm depths. Four weeks after broadcast application in the wheat trial, we observed a significant increase in soil moisture and microbial biomass in the 5–15 cm-depth and a decrease in soil nitrate at both soil depths and across rates, relative to unamended plots (p < 0.1). We also saw a non-significant 14% increase in corn yield with subsurface banding of lactobionate but no observed changes in other soil properties measured in the corn trial. We found no significant changes in soil pH, total soil carbon and nitrogen, and soil ammonium concentration with lactobionate for both trials. Our observations suggest the potential for lactobionate to modify soil water content, microbial biomass, nitrate, and yield but outcomes varied by crop trial and amendment rates. This implies that while recycling food waste for use as a soil amendment may have benefits for key soil health parameters, the timing, mode and application amount need to be optimized for maximal effects of lactobionate.