Abstract:

To explore the effect of straw returning combined with composting agent on maize seedling, the natural fermentation of 40 g/L, 50 g/L, 60 g/L and 70 g/L corn straw soil extract and fermentation broth of decomposed agent were used as test materials. The seed germination rate, root length, root number, plant height, fresh weight, free proline and malondialdehyde content were measured by filter paper culture, pot culture and conventional methods. The results showed that the seed germination rate, root length, root number, root fresh weight, plant height and leaf fresh weight increased first and then decreased with the increase of fermentation broth concentration. The values of the above indexes of fermentation broth with the same-concentration decomposed agent were higher than that of natural fermentation broth, and the germination rate of 50 g/L natural fermentation and 60 g/L fermentation broth of decomposed agent was relatively high; the fermentation broth of composting agent significantly increased the root length of seedlings; 50 g/L fermentation broth of decomposed agent significantly increased the number of roots; all treatments had no significant effect on the fresh weight of root, leaf and plant height. The contents of free proline and malondialdehyde in roots and leaves of 50 g/L natural fermentation broth and 60 g/L composting agent fermentation broth were not significantly different from those in soil extract. In general, 50 g/L natural fermentation and 60 g/L fermentation broth of composting agent could significantly promote the growth of maize seedlings. The allelopathy of corn straw combined with composting agent fermentation could be weakened, and the amount of straw returned to the field should be appropriately increased when straw is returned to the field.

Key words: straw fermentation broth, seed germination rate, malonic acid content, free proline content