Soil Aeration And Plant Growth Response To Urea Peroxide Fertilization

ABSTRACT We conducted experiments designed to determine if soil aeration could be improved and if the oxygen stress brought about by flooding could be reduced by addition of peroxide to the soil-root medium. Tomato plants (Lycopersicon esculentum Mill.) growing in containers filled with a potting mix of peat moss and sand were subjected to combinations of treatments with and without flooding and peroxide additions. Aeration status of soil mixes during the study was measured with platinum microelectrodes for redox potentials (EH7) and oxygen diffusion rates (ODR). Plant heights were measured at weekly intervals, and shoots were harvested for fresh and dry weights. The growth of tomato plants watered as required was not increased by peroxide fertilization. Plants that were flooded, however, did grow significantly better when peroxide was included in either the flooding solution or the watering solution after flooding. Redox potential measurements, taken after 48 hours flooding, were below the value of 320 to 340 mV, at which point oxygen becomes depleted from soil. The high ODR values indicated good oxygen availability in the mix prior to the first flooding and prior to harvesting.