Carbon isotope analysis to evaluate C4/C3 rooting patterns in a living mulch cropping system. (C03-eleki298157-poster)
Authors:
K. Eleki* - Iowa State University R.M. Cruse - Iowa State University K.A. Albrecht - University of Wisconsin
Abstract:
Kura clover (Trifolium ambiguum M. Bieb.) is a potential living mulch for corn (Zea mays L.) production, although above and/or below ground interspecies competition may exist. The objective of this study was to develop a method for segregating root material by species from soil samples taken in a mixed stand so that the effect of kura clover top growth suppression on root growth patterns, and therefore potential below ground competition, could be determined. Two treatments were compared: 1) a 25-cm band of above ground growth centered on the cornrow was suppressed with herbicides, and 2) a broadcast application of herbicides suppressed all above ground kura clover growth. Soil cores with corn and kura clover roots were obtained at three distances from the corn row at two depths.
Root discrimination of C4 and C3 species was based on 13C ratio analysis. A linear relationship (R2=0.99) found in delta 13C vs. percentage corn roots in calibration samples was used to determined corn and kura root percentages within field cores. The kura clover root mass distance (from the corn row) by suppression treatment interaction was significant, indicating suppression treatment affected kura clover root pattern. 13C isotope analysis was suitable to discriminate corn and kura clover root
materials in mixed cropping culture and seems a good approach for root segregation of C4 and C3 species.
Speaker Information: Krisztina Eleki, Iowa State University, 3010-Agronomy Hall, Ames, IA 50013;
Phone: 515-294-2800; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 513)
Keywords: corn; kura clover; root mass; living mulch management