Submitted to: Minnesota Academy of Science Meeting
Publication Type: Proceedings
Publication Acceptance Date: 4/25/2003
Publication Date: 4/25/2003
Citation: BARBOUR, N.W., JOHNSON, J.M. DECOMPOSING PLANTS -- DOES COMPOSITION AND PLANT PART AFFECT DECOMPOSITION RATE? CD-ROM. ST. PAUL, MN: MINNESOTA ACADEMY OF SCIENCE. 2003.
Technical Abstract: Understanding decomposition of plant residue is vital to understanding C and N cycling, both in terms of plant nutrient needs and global change. Roots typically constitute less than half the total plant biomass, but the literature suggests they contribute 1.4 to 1.8 times as much C to the soil as above-ground plant biomass. This study addresses the related issues of plant composition, residue decomposition, and C and N cycling. The first objective was to compare the biochemical composition of roots, both among species and with leaves and stems. The second objective was to evaluate the decomposition rates of roots, leaves and stems among species and the relationships among biochemical components and C and N mineralization rates. Plant materials from C3 and C4 species were collected at physiological maturity. Structural and nonstructural components from roots, stems and leaves were measured. Decomposition of plant material in soil was monitored as evolved CO2 at 25 deg C and 60% water-filled pore space. Chemical composition and decomposition varied among species and plant organs.