Influence of waterlogging on yield of wheat (Triticum aestivum), redox potentials, and concentrations of microelements in different soils in India and Australia

Abstract

Effects of waterlogging relative to drained conditions on grain yield were studied in relation to soil redox potentials and microelements (Fe and Mn) in soils from India and Western Australia, using waterlogging intolerant and tolerant varieties of wheat (Triticum aestivum L.) The grain yield of wheat decreased significantly with increasing duration of waterlogging in sodic soils. In Indian soils, soil redox potentials decreased sharply after waterlogging and were 150 and 210 mV at 10 days after waterlogging in alkali soil at pH 8.5 and pH 9.2, respectively. Two Australian soils were similarly reduced in redox potential with values of ~200 mV at 10 days after waterlogging, and redox potentials were further reduced to 100 mV and –50 mV for soils without and with added glucose, respectively, after 40 days of waterlogging. The Indian soils tended to be 2–10 times higher in DTPA-Mn than the Australian soils, whereas the Australian soils were up to 10 times higher in DTPA-Fe than the Indian soils. These increases were up to 10 and 60 times higher, respectively, than reported critical concentrations for wheat. After 21 days of waterlogging, the Indian soils were drained, and the re-aeration resulted in an increase in redox potential and a decrease in DTPA-Fe and -Mn in soil solutions, but this occurred slowly, taking 15–25 days. The results support the hypothesis that waterlogging tolerance is a product of tolerance to anoxia and microelement toxicities, and that these are both key factors limiting plant growth during and after waterlogging. These factors may also contribute to the large differences in screening wheat varieties for waterlogging tolerance in different soils.