增氧灌溉对盆栽冬小麦生长及土壤通气性的影响

Impacts of oxygenated irrigation on potted winter wheat growth and soil aeration

以冬小麦为供试作物,以普通地下滴灌为对照(CK),设置循环曝气(VAI)、双氧水(HP30、HP3K)三种增氧灌溉处理,系统监测土壤通气性、作物根系生长和养分吸收利用状况,研究土壤通气性与冬小麦生长的响应规律。结果表明,增氧灌溉可显著改善土壤通气性,与对照相比,灌溉后2d内土壤通气性指标有显著改善,其中,VAI和HP30处理拔节期20cm土层氧气扩散速率增大了43.99%和21.37%,VAI处理土壤呼吸增大了106.62%。增氧灌溉促进了作物根系生长,VAI处理0~10cm土层根系总表面积和根长密度增加了44.18%和37.21%,HP30处理0~10cm土层根长密度和根系总体积提高了21.13%和32.69%;增氧灌溉下作物的生理指标较对照有显著提高,其中,VAI、HP3K和HP30处理灌浆期光合速率提高了43.41%、26.37%和20.37%,VAI和HP30处理灌浆期气孔导度增大了23.53%和17.65%,蒸腾速率提高了11.61%和15.83%;同时,VAI处理和HP30处理产量提高了36.27%和23.37%,VAI处理水分利用效率增大了38.98%,均存在显著性差异。综上,增氧灌溉改善了作物根区的土壤通气性,促进了作物根系生长,提高了作物产量和水分利用效率,其中,VAI处理的改善效果最佳。

Perched water often leads to decrease in soil aeration of crop roots in subsurface drip irrigated soils. Oxygation provides a source of oxygen in root environment that suffers from temporal hypoxia and unlocks yield potentials of crops. However, the effect of oxygation on soil aeration was not well known. With winter wheat as a test crop, four irrigation treatments were used including venturi cyclic aeration irrigation (VAI), hydrogen peroxides 3000 (HP3K) solution, hydrogen peroxides 0030 solution (HP30), and a control treatment (CK). Subsurface drip irrigation was implemented, and the soil aeration, crop root growth, physiological indexes, and yield were systematically monitored. The effect of oxygation on potted winter wheat growth and soil aeration was studied. Compared with the control treatment, the soil respiration in VAI increased by 106.62%, the oxygen diffusion rate in VAI and HP30 increased by 43.99% and 21.37%, respectively. Meanwhile, the total surface areas and root length density in VAI increased by 21.13% and 32.69%, and root length density and root volume in HP30 increased by 21.13% and 32.69%, respectively, compared with that of CK. The photosynthetic rate, stomatal conductance, and transpiration rate were enhanced by oxygation. Compared with CK, the photosynthetic rates in VAI, HP3K, and HP30 increased by 43.41%, 26.37%, and 20.37%, respectively;the stomatal conductance in VAI and HP30increased by 38.78% and 17.65%, the transpiration rate in VAI and HP30 increased by 21.55% and 15.83%, respectively. The yield in VAI and HP30 significantly increased by 36.27% and 23.37%, respectively, over that in CK, while the WUE in VAI significantly increased by 38.98%. In conclusion, subsurface aerated drip irrigation with aerated water improved the hypoxic environment in rhizosphere, thus enhanced the soil aeration and crop growth with increased crop yield as well as water utilization efficiency. Among the three aerated treatments, the enhancement effect in VAI was the best among the treatments.