c/o Department of Soil Science
North Carolina State University
PO Box 7619
Raleigh, North Carolina 27695-7619
Room: c/o SSC
Specialty: Plant Nutrition and Physiology
The Stable Isotopes Program includes research on selected aspects of plant nutrition, ion uptake, nitrate assimilation and the regulation of these processes by photosynthetic carbohydrate and energy supply. Both C3 and C4 plant species are used to examine the effects of nutritional and environmental stress on physiological pathways which limit plant productivity. Facilities are available for on-line studies of gas exchange processes such as nitrogen fixation and photo respiration. Such studies commonly involve the use of mass spectrometry and stable isotopes of nitrogen, carbon and oxygen.
- Glasener, Karl M., Michael G. Wagger, Charles T. MacKown, and Richard J. Volk. 2002. Contributions of shoot and root nitrogen-15 labeled legume nitrogen sources to a sequence of three cereal crops. Soil Sci. Soc. Am. J. 66:523-530.
- Crozier, C. R., L. D. King, R. J. Volk. 1998. Tracing N movement in corn production systems in the North Carolina Piedmont: a nitrogen-15 study. Agron. J. 90:171-177.
- Glasener, K. M., M. G. Wagger, C. T. MacKown, and R. J. Volk. 1998. Nitrogen-15 labeling effectiveness of two tropical legumes. Plant and soil 200: 149-156.
- Volk, R. J. 1997. Unidirectional fluxes of nitrate into and out of maize roots: Measurement and regulation by prior nitrate nutrition. Plant Sci. 123:1-7.
- Jackson, W. A., and R. J. Volk. 1995. Attributes of the nitrogen uptake systems of maize (Zea mays L.): Maximal suppression by exposure to both nitrate and ammonium. New Phytol. 130:327-335.
- Jackson, W. A., and R. J. Volk. 1992. Nitrate and ammonium uptake by maize: adaptation during relief from nitrogen suppression. New Phytol. 122:439-446.
- Volk, R. J., S. Chaillou, A. Mariotti, and J.-F. Morot-Gaudry. 1992. Beneficial effects of concurrent ammonium and nitrate nutrition on the growth of Phaseolus vulgaris: a 15N study. Plant Physiol. Biochem. 30:487-493.
- Pace, G. M., R. J. Volk, and W. A. Jackson. 1990. Nitrate reduction in response to CO2-limited photosynthesis: Relationship to carbohydrate supply and nitrate reductase activity in maize seedlings. Plant Physiol. 92:286-292.