Root and shoot growth of Oryza sativa L. as affected by redox potential
1988
Sekhon, N. | Sur, H.S. | Singh, N.T. (Punjab Agricultural Univ., Ludhiana (India). Soils Dept.)
Root and shoot growth responses to levels of soil reduction were compared. Iron pots 1m high and 50 cm in diameter were uniformly packed with a loamy sand (Typic Ustochrept) and different levels of redox potential created using the treatments control (soil kept near 60% field capacity), submergence (4-6 cm standing water), submergence + 0.5% starch, and submergence + 1% starch. One day after treatment, 21 seedlings of cultivar PR106 were transplanted into each pot. Recommended doses of fertilizers were used. All measures, except shoot and grain weight, were recorded at panicle emergence. The redox potential created ranged from +343mV to -396. Decrease in Eh from +343 to +70mV significantly improved growth measures except for total chlorophyll content. Lowering Eh to -97mV further improved all measures including the chlorophyll content. Further decrease in redox potential did not improve growth but significantly reduced tillers, leaf area, and root density. The amount of roots increased in the surface 5 cm soil layer with decrease in redox potential from +343 to -396mV. Growth improvement with decrease in Eh to -97mV could be explained by better tissue hydration, higher availability and uptake of nutrients and improved soil physical conditions. Further reduction may lead to accumulation of toxic products.
显示更多 [+] 显示较少 [-]