Publication Date

1997

Description

The objective of these studies was to determine the reasons for chlorosis of desmanthus observed at some sites in southeast Queensland. Inoculation with Rhizobium increased growth of desmanthus in 2 of 4 soils in the field and 4 of 8 soils in pots. Greatest responses occurred in soils with few or no effective native Rhizobium. Most soils however, contained native strains that were effective. Omission of sulphur significantly reduced dry weight of desmanthus grown in pots in 5 of 7 soils by 30-51% relative to plants supplied with all nutrients. Omission of P and Mo resulted in similar yield reductions in one soil each. Both S and Mo deficiency significantly reduced nitrogen concentrations in leaf tissue. Chlorosis therefore appears to be due to low or absent native Rhizobium and/or deficiency of S or Mo. More work needs to be done in the field to determine the extent of nutrient deficiencies and to improve methods of inoculation.

Share

COinS
 

Rhizobial and Nutritional Responses of Desmanthus Clay Soils of Queensland

The objective of these studies was to determine the reasons for chlorosis of desmanthus observed at some sites in southeast Queensland. Inoculation with Rhizobium increased growth of desmanthus in 2 of 4 soils in the field and 4 of 8 soils in pots. Greatest responses occurred in soils with few or no effective native Rhizobium. Most soils however, contained native strains that were effective. Omission of sulphur significantly reduced dry weight of desmanthus grown in pots in 5 of 7 soils by 30-51% relative to plants supplied with all nutrients. Omission of P and Mo resulted in similar yield reductions in one soil each. Both S and Mo deficiency significantly reduced nitrogen concentrations in leaf tissue. Chlorosis therefore appears to be due to low or absent native Rhizobium and/or deficiency of S or Mo. More work needs to be done in the field to determine the extent of nutrient deficiencies and to improve methods of inoculation.