Long-Term Effects of Clipping and Nitrogen Management in Turfgrass on Soil Organic Carbon and Nitrogen Dynamics: The CENTURY Model Simulation

• Published in: Journal of environmental quality 2003-09, Vol.32 (5), p.1694-1700
• Main Authors: Qian, Y.L, Bandaranayake, W, Parton, W.J, Mecham, B, Harivandi, M.A, Mosier, A.R
• Format: Article
• Language: English
• Subjects: age; Biodegradation, Environmental; Carbon - metabolism; Carbon sequestration; Clay loam; Conservation of Natural Resources; Decision Making; decision support systems; Ecosystem models; Environmental impact; Environmental Pollution - prevention & control; fertilizer rates; Fertilizers; grass clippings; lawns and turf; Leaching; long term experiments; Models, Theoretical; mowing; Nitrogen; Nitrogen - metabolism; nutrient management; Organic carbon; Organic nitrogen; Plant Leaves - metabolism; plant residues; Poa - chemistry; Poa - metabolism; Poa pratensis; simulation models; soil nutrient dynamics; soil organic carbon; Soil Pollutants; Soils; Turf; turf grasses; turf management; yields
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2003.1694

Experiments to document the long-term effects of clipping management on N requirements, soil organic carbon (SOC), and soil organic nitrogen (SON) are difficult and costly and therefore few. The CENTURY ecosystem model offers an opportunity to study long-term effects of turfgrass clipping management on biomass production, N requirements, SOC and SON, and N leaching through computer simulation. In this study, the model was verified by comparing CENTURY-predicted Kentucky bluegrass (Poa pratensis L.) clipping yields with field-measured clipping yields. Long-term simulations were run for Kentucky bluegrass grown under home lawn conditions on a clay loam soil in Colorado. The model predicted that compared with clipping-removed management, returning clippings for 10 to 50 yr would increase soil C sequestration by 11 to 25% and nitrogen sequestration by 12 to 28% under a high (150 kg N ha−1 yr−1) nitrogen (N) fertilization regime, and increase soil carbon sequestration by 11 to 59% and N sequestration by 14 to 78% under a low (75 kg N ha−1 yr−1) N fertilization regime. The CENTURY model was further used as a management supporting system to generate optimal N fertilization rates as a function of turfgrass age. Returning grass clippings to the turf–soil ecosystem can reduce N requirements by 25% from 1 to 10 yr after turf establishment, by 33% 11 to 25 yr after establishment, by 50% 25 to 50 yr after establishment, and by 60% thereafter. The CENTURY model shows potential for use as a decision-supporting tool for maintaining turf quality and minimizing negative environmental impacts.