Effects of mutual aid grow seedlings of cotton with other crops in the sameaperture on soil microorganisms quantity, enzyme activity and root secretion

To reveal the mechanism of promoting the growth of cotton seedlings using other seedlings, effects of mutual aid grow seedlings of cotton with wheat, maize, millet and sorghum separately in the same aperture on soil microorganisms quantity and enzyme activity and root secretion were studied using 532 mm280 mm lastic tray with 200 square holes full of soil under greenhouse and natural light condition. The results indicated that the amounts of soil bacteria and actinomyces under the mutual aid grow seedlings of cotton with other crops in the same apertures are significantly increased, while the amounts of soil fungi are significantly decreased. The activities of soil dehydrogenase, neutral phosphatase, zymose and urease are increased significantly, and the accumulations of 2,4-ditertbutylphenol, 2,6-ditertbutylphenol, dibutyl phthalate and methyl palmitoleate are decreased significantly, which results in the increases of root vitality, the contents of soluble sugar and ATP in the leaves, the weights of cotton seedlings and roots and the number of lateral roots. Moreover, survive days depart from seedbed are increased, while the convalescent period of seedlings after transplanting are shortened compared with that in single cotton seedling treatment. Among the treatments, wheat and millet are the best choices to promote the growth of cotton seedlings. In conclusion, the mutual aid grow seedlings of two different crops in the same aperture can improve the soil microbial structure and amount, and the cotton seedling quality these are possibly primary causation of the increases of the soil enzyme activities and the decreases of the accumulation of harmful root exudates.