The effect of soil type on the establishment, early growth and nodulation of Glycine wightii

Abstract

A pot investigation was made of the establishment, nodulation, and early growth of Glycine wightii (CV. Tinaroo) on five soil types, black-earth, alluvium, yellow podzolic, krasnozem, and a siliceous sand. Soil physical and chemical properties were measured. Previous observations that the species is slow to establish on some soils has been confirmed quantitatively. Nodules were not recorded before day 27 after planting regardless of soil type. Nodulation proceeded at a faster rate in the early stages on the black earth and alluvium. There appeared to be two phases in the rate of nodulation on the krasnozem, an initial lag period followed by a marked increase. On the podzolic, the lag phase was more pronounced and a third phase of nodule loss occurred after day 62. Changes in nodule weight per pot were a function mainly of changes in nodule number. Nodule weight was also linearly related to root dry weight. Total dry matter prior to the formation of nodules appeared to be related to the supply of soil nitrogen. After nodule initiation the pattern of plant growth was similar to that of nodulation. The efficiency of nitrogen fixation on the podzolic was significantly lower than on the other soil types. The practical implications of the results are discussed briefly.