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| DOI：10.13522/j.cnki.ggps.2017.0228 |
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| The Combined Impact of Water and Potassium on Root Growth and Potassium Distribution in the Rhizosphere of Rice |
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ZHAO Zhicheng, WANG Weimu, GUO Xiangping
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Broadvision Engineering Consultants, Kunming 650041, China; College of Water Conservancy and Hydropower, Hohai University, Nanjing 210098, China; Southern Region Efficient Irrigation and Drainage Key Laboratory of Agricultural Soil and Water Environment, Ministry of Education,Hohai University, Nanjing 210098, China
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| Abstract: |
| 【Objective】 Water and nutrient distributions in soil modulate root growth, and the purpose of this paper is to investigate the combined impact of water and potassium on root growth and potassium distribution in the rhizosphere of rice. 【Method】 Pot experiments were carried out with the variety of Wuyun japonica rice as the model plant. We examined three soil saturations: 70%θf~80%θf, 80%θf~90%θf and 100%θf , and three potassium levels: 0, 100 mg and 200 mg per pot. When the rice seedling was at the six-leaf stage, we measured the amount of dry matter, root-shoot ratio, root activity, as well as the potassium content in the rhizosphere. 【Result】 Soluble potassium content in the rhizosphere was proportional to total potassium content and decreased with soil depth. Along the soil profile, the slow-K content was proportional to the applied potassium and decreased with soil depth. Potassium application impeded the accumulation of above-ground biomass at early growing stage, while a slight water stress enhanced root growth and the root-shoot ratio. The experimental results revealed that soil moisture modulated root growth while potassium impacted mainly on shoot growth. 【Conclusions】 The onset of water and potassium is the root and they are then extended to the shoot and canopy. |
| Key words: rice; water and potassium coupling; rhizosphere; potassium states; spatial distribution |
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