Abstract:

To explore the optimal amount of maize stalks added to the saline-alkaline soil, we used ‘Nonghua 101’ maize seeds, harvested maize stalk powder and typical saline-alkali soil in Tongliao as materials, prepared soil extract of saline-alkali soil: distilled water (1:5) to make 30, 40, 50, 60 g/L straw powder culture solution as five treatments, and conducted hydroponic culture of maize seeds. The pH, electrical conductivity, number of microorganisms and number of endophytes in the roots of maize seedlings were measured during the cultivation period, and the germination rate of maize seeds was tested, the agronomic traits of seedlings and the physiological characteristics of leaves and roots at the four-leaf stage were studied. The results show that the addition of maize stalks in saline-alkali soil could reduce the soil pH and the germination rate of maize seeds, but significantly increase the root length, root number and plant height of seedlings; the 40 g/L treatment has the largest increase of root length and root number, the treatment of 0 g/L has seedling death at the two-leaf stage. The addition of straw could significantly increase the number of saline-alkali soil bacteria, except the 30 g/L treatment, the other treatments significantly increase the number of fungi and actinomycetes. There is no significant difference between root endophytic fungi and actinomycetes, the number of root endophytic bacteria in 30 g/L and 40 g/L treatment is significantly higher than that in 50 g/L and 60 g/L treatment. The POD activity of leaves of 40 g/L treatment is significantly higher than that in 50 g/L and 60 g/L treatment, which is 2.22 and 3.15 times, respectively. The MDA content of the leaves is 60 g/L>50 g/L>30 g/L>40 g/L, and the difference among the treatments is extremely significant. The SOD activity of leaves and root activity are 40 g/L>50 g/L>60 g/L>30 g/L, with extremely significant difference among the treatments. The root MDA content is 60 g/L>30 g/ L>50 g/L>40 g/L, and extremely significant difference is also found among the treatments. The law of root POD activity of each treatment is consistent with root activity. Therefore, adding maize stalk powder to saline soil could increase maize seedlings’ resistance to salt-alkali stress, and the effect of 40 g/L treatment is the most significant.

Key words: maize, saline-alkali soil, maize stalk addition, seed germination, growth characteristics of seedling