The development of manganese toxicity in pasture legumes under extreme climatic conditions

✍ Scribed by A. Siman; F. W. Cradock; A. W. Hudson

• Book ID: 104614478
• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 508 KB
• Volume: 41
• Category: Article
• ISSN: 0032-079X
• DOI: 10.1007/bf00017950

✦ Synopsis

Manganese levels and pH in soil were measured on limed and unlimed plots at bi-monthly intervals for two years at five field sites with lucerne (Medicago saliva) and subterranean clover (Tri/olium subterraneum) and related to rainfall and temperature. Pot experiments with lucerne, subterranean clover and rape (Brassica campestris) were used to confirm the results of the field experiments.

Manganese toxicity developed in lucerne and subterranean clover under waterlogged conditions after heavy rain on the slightly acid soils (pH 4.7-5.5). Lucerne also showed manganese toxicity on the same soils in summer after extended hot, dry conditions. The maximum available manganese was 210 vg/g in the waterlogged soil (0-15 cm) and 128 tzg/g in the heat affected soil.

Lime treatment of 2240 kg/ha reduced the maximum available manganese to 148 ~g/g in waterlogged plots and to 47 ~g/g in the heat affected plots but failed to correct manganese toxicity. However, lime corrected toxicity symptoms under less severe conditions.

In the pot experiments, available manganese reached 270 ~xg/g after 2 weeks artificial waterlogging and 68 ~g/g after 2 weeks dry heat exposure.