Abstract:

The different proportions of fermented bark medium (fermentable bio-fertilizer) were mixed into the saline-alkali soil with Krilium (HPMA) for improving saline-alkali soil. Linum usitatissimum and Sorghum bicolor were grown in the modified soils with different proportions of mixtures (0∶1; 4∶1; 2∶1; 1∶1, of the medium to the saline-alkali soil) with HPMA. The results showed: 1) The modified saline-alkali soil had a reducing tendency in pH value and electrical conductivity. In treatment 4（1∶1 with HPMA）, pH value decreased to 8.8, which was 1.7 units lower than that of the control saline-alkali soil and was close to non-saline-alkali soil (pH 8.3); The soil electrical conductivity in treatment 4 was 481.4 μS·cm^-1, which was 21.7% lower than that of control saline-alkali soil (614.5 μS·cm^-1). Addition of the fermented bark medium obviously increased the soil organic matter and ascending height of soil capillary water. 2) The addition of the fermented bark medium remarkably increased the growth of seedlings although different plants had different heights in different treatments. 3) Additions of the fermented bark medium all increased contents of soluble sugars, and obviously declined the contents of free proline of the plants. The changes increased with increased proportions of fermented bark. The results showed that the fermented bark had a significant role in decreasing the saline-alkali soil stress on plant growth. The more fermented bark medium proportion was added, the remarkable effect was obtained in improving the saline-alkali soil. In view points of economics, the treatment 2 (4∶1 with HPMA) showed the better efficiency for saline-alkali soil improvement.

Key words: saline-alkali soil, ferment tree bark soil (fermentable bio-fertilizer), free proline, soluble sugar, Krilium (HPMA)