Weather and nodule mediated variations in delta 13C and delta 15N values in field-grown soybean (Glycine max L.) with special interest in the analyses of xylem fluids.

The nodulating soybean (Enrei) and its non-nodulating mutant (EN 1282) were grown in outdoor plots for 2 years (1994: extraordinary dry, high temperature, 1995: ordinary year). Carbon and nitrogen accumulation, delta 13C and delta 15N values in plant parts and xylem fluids and delta 15N values in the water-extractable soil N were analysed throughout the growing period. Plant growth in 1994 was rapid during the early growth stages, but no pods were produced.

Root porosities and radial oxygen losses of Rumex and Plantago species as influenced by soil pore diameter and soil aeration.

The effects of hypoxia in ballotini and quartz sand with respectively large and small soil pore diameters on root porosity was studied for Rumex palustris Sra., Rumex acetosa L. and Plantago major L.