Soil nutrient and erosion dynamics following compost application on annual grass-dominated rangelands

Authors: Phillips, Jacob; Newingham, Beth; DUNHAM-CHEATHAM, SARRAH - University Of Nevada; Williams, Christopher; Mueller, Rebecca; BOWER, ALAN - Natural Resources Conservation Service (NRCS, USDA); MORRA, BRIAN - ARS Postdoctoral Research Associate; SIEWERT, ELIZABETH - University Of Nevada; HAVRILCHAK, NICOLE - ARS Postdoctoral Research Associate

Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2024
Publication Date: 2/10/2025
Citation: Phillips, J.D., Newingham, B.A., Dunham-Cheatham, S.M., Williams, C.J., Mueller, R.C., Bower, A., Morra, B., Siewert, E., Havrilchak, N. 2025. Soil nutrient and erosion dynamics following compost application on annual grass-dominated rangelands. Society for Range Management Meeting Abstracts. 78:17.

Interpretive Summary:

Technical Abstract: Rangelands that experience excessive runoff and erosion can transition to a degraded state of reduced organic matter and soil nutrients and impact the local water quality. Additions of organic soil amendments can enhance soil nutrient and physical properties and is a common practice in croplands and pasturelands. Despite the benefits, this practice is not common on rangelands. This study evaluates two different rates of surface compost application on rangelands, with a focus on soil physical and chemical properties, surface runoff, and soil erosion following compost application. An annual grass-dominated site was selected in California with hill slopes ranging from 5-15%, and compost was applied to plots at 0, 8, or 15 tons acre-1. Additionally, half the plots received simulated rainfall to monitor the hydrological effects of compost on the soil. Water runoff samples were collected from the rainfall plots throughout the rain event, and soil cores were collected for all plots at multiple depths. The average organic carbon concentration in runoff was 4 and 6 times greater than non-compost controls for 8 and 15 tons acre-1, respectively. Similarly, nitrogen concentrations in runoff were 1.5 (8 tons acre-1) and 2.5 (15 tons acre-1) times greater than non-compost controls. This overall trend for organic carbon and nitrogen concentrations in runoff samples indicates that organic matter and soil nutrients may be lost from annual grass-dominated rangelands after soil amendment applications.