The Role of Soil Organic Matter and Manures in Sustainable Nutrient Cycling - Sustainable Management of Soil Organic Matter - page 306

found under conditions of elevated CO 2 . The potential impact of elevated
CO 2 on soils of agroecosystems may be important for the future manage-
ment and productivity of these systems because small improvements in soil
organic C can have important positive influences on soil physical properties
such as soil hydraulic conductivity, soil bulk density, soil porosity, soil
aggregate stability, soil water retention and rainfall infiltration.

Acknowledgements

The authors are indebted to Robert F. Chaison, Barry G. Dorman and
Tammy K. Dorman for technical assistance. Support from the Office of
Biological and Environmental Research/Environmental Sciences Division,
US Department of Energy (Interagency Agreement No.
DE-AI05-95ER62088) and the Alabama Agricultural Experiment Station,
Auburn University, is gratefully acknowledged.

References

Buyanovsky, G.A., Wagner, G.H. and Gantzer, C.J. (1986) Soil respiration in a
winter wheat ecosystem. Soil Science Society of America Journal 50, 338-344.
Ghidey, F. and Alberts, E.E. (1993) Residue type and placement effects on
decomposition: field study and model evaluation. Transactions of the American
Society of Agriculture Engineers 36, 1611-1617.
Potter, K.N., Torbert, H.A., Jones, O.R., Matocha, J.E., Morrison, J.E. Jr and
Unger, P.W. (1998) Distribution and amount of soil organic carbon in
long-term management systems in Texas. Soil and Tillage Research 47,

309-321.
Prior, S.A., Rogers, H.H., Runion, G.B., Torbert, H.A. and Reicosky, D.C.
(1997a) Carbon dioxide-enriched agro-ecosystems: influence of tillage on
short-term soil carbon dioxide efflux. Journal of Environmental Quality 26,
244-252.
Prior, S.A., Torbert, H.A., Runion, G.B., Rogers, H.H., Wood, C.W., Kimball,
B.A., LaMorte, R.L., Pinter, P.J. and Wall, G.W. (1997b) Free-air carbon
dioxide enrichment of wheat: soil carbon and nitrogen dynamics. Journal of
Environmental Quality 26, 1161-1166.
Rogers, H.H., Heck, W.W. and Heagle, A.S. (1983) A field technique for the study
of plant responses to elevated carbon dioxide concentrations. Air Pollution
Control Association Journal 33, 42-44.
Rogers, H.H., Runion, G.B., Prior, S.A. and Torbert, H.A. (1999) Response of
plants to elevated atmospheric CO 2 : root growth, mineral nutrition, and soil
carbon. In: Luo, Y. and Mooney, H.A. (eds) Carbon Dioxide and Environmental
Stress . Academic Press, San Diego, California, pp. 215-244.
Smith, S.D., Jordan, D.N. and Hamerlynck, E.P. (1999) Effects of elevated CO 2
and temperature stress on ecosystem processes. In: Luo, Y. and Mooney, H.A.