The Influence Of Acid Aluminum Stress And Soil Amendment On The Growth Of Trifolium Repens

Aluminum toxicity is one of the most important factors that limiting crop growth in acidic soil. This study selects trifolium repens as the experimental material. It adopts artificial climate chest. Through the determination of trifolium repens seed germination and seedling physiological and biochemical indexes under acid stress and aluminum stress environment, it explores the influence of acid stress and aluminum stress on seed germination and seedling growth after 20 days germination. On this basis, to solve southern soil acidification problem, it applies greenhouse pot experiment to discuss the influence of soil conditioner on acid soil improvement effect and trifolium repens. The main results were as follows:Germination and seedling growth of trifolium repens show obvious differences under different pH environment. When pH is greater than 4.0, the growth index of trifolium repens is significantly higher than the environment whose pH is less than 4. When pH=2.0, trifolium repens seed root length, stems length, germination rate, germination potential, germination index, seedling growth potential, vigor index, chlorophyll content, electrical conductivity, soluble sugar content, dissociated proline content, malondialdehyde content, peroxidase activity are severely affected. It suggests that with the increase of acidity, the inhibition of trifolium repens seed germination and seedling growth strengthen. Under slightly acidic environment (pH=6.0), it shows no inhibition, even plays a role of promoting. When pH value is between 5.0 and 7.0, the growth index of trifolium repens is significantly higher than other conditions, which indicates that the range of 5.0-7.0 is suitable for trifolium repens germination and seedlings growth.If acid and aluminum two stress factors work together, it exerts great effects on the germination and seedling physiological activity of T. repens. The test shows that under the condition of same pH, aluminum toxicity makes trifolium repens seed germination rate, germination potential, germination index, seedling growth potential, vigor index, root length, stems length and chlorophyll content on the decline with the increase of Al3+ content; it makes the electrical conductivity, soluble sugar content, dissociated proline content, malondialdehyde content and peroxidase activity increase with the increase of Al3+ content. And when the pH value is 3.5, trifolium repens is more sensitive to the environment whose aluminum toxicity reaction rate is pH4.5,5.5 and 7.0. The difference is more obvious when pH is 3.5 and Al3+ content is 200 mg/L. As can be seen, acid aluminum stress has affected trifolium repens seedling germination and normal growth.The application of flue gas desulfurization gypsum and quicklime combined modifier on the acid soil can significantly increase the pH of the soil, reduce soil bulk density, improve soil structure, increase the soil aggregated structure and porosity. At the same time, physical and chemical indexes including soil organic matter, rapid available phosphorus, rapid available nitrogen and rapid available potassium content increase at different degrees. Therefore, flue gas desulfurization gypsum and quicklime combined modifier can improve acid soil significantly so as to promote the growth of trifolium repens.