| Paddy-upland rotation strongly convert hydrothermal conditions leads to the changes of soil microorganisms and soil enzymes in soil environment. To explore the impact of water-drought conversion process in paddy-upland rotation for the biological properties of soil, microbial quantity and distribution of ecological soil enzyme activity in the soil, Select potatoes-rice,rapeseed-rice, winter paddy-rice, potatoes-maize model for the study, with different types of crop rotation pattern is a comparative analysis of water-drought conversion process in paddy-upland rotation of 0-10cm,10-20cm soil microbial population (bacteria, actinomycetes, fungi) and two kinds of enzymes (invertase, urease). The results show:(1) Water-drought conversion process by measuring the amount of 10 times per gram of dry soil microorganisms found in soil that over time the total number of microbes, bacteria, actinomycetes in both soil waterlogged state have shown higher than moist in drying and rewetting. That is, each field irrigation water dry naturally after falling, the number of bacteria are on the rise. Water-drought conversion process water regulates soil bacteria, actinomycetes. In drying and rewetting., fungi exhibit only in the upper soil and bacteria, the same trend actinomycetes, fungi changes in soil moisture more biased in favor of the regulation of topsoil. By comparing the water-drought and water-water pattern discovery, water-drought conversion process the number of microbes decreased in the water-drought mode, water-water mode rise. Water-drought conversion the change of total microbial is same with the bacteria, the change of the bacteria determines the change of the total number of soil microorganisms.Water-drought conversion process by measuring the amount of 10 times the number of soil microbes in upper and lower layers, in drying and rewetting bacteria, actinomycetes and fungi in water-drought mode showed the upper is higher than the lower layers, while in drought-drought mode showed the upper is lower than the lower layers. In the late time, compared to water-drought and water-water pattern discovery, water-drought mode in the number of bacteria shows the upper is less than the lower layers. Water-drought mode actinomycetes and fungi shows the upper are higher than the lower layers. In water-water mode bacteria, actinomycetes and fungi showed the upper were less than the lowerlayers.(2) Water-drought conversion process by measuring the invertase activity found that invertase activity fall in roughly,keep steady in drying and rewetting, rise in the late. Water-drought, water-water and drought-drought patterns show the same trends, water-drought conversion process for invertase activity is not obvious. Compare water-drought, water-water and drought-drought pattern discovery, in the late drought-drought mode invertase activity is above the water-drought, water-water mode.Water-drought conversion process by measuring the urease activity found that urease activity in roughly and drying and rewetting fluctuate significantly, after the August 15 change of the trend keep stable. Water-drought, water-water and drought-drought patterns show the same trends, water-drought conversion process for for urease activity is not obvious. In this study, comparison of water-drought and drought- drought pattern in the upper soil found water-drought mode urease activity was significantly higher than the drought-dry mode; and contrast water-drought and drought-drought mode subsoil found the results differ from the upper soil, and urease activity difference between them narrowed.Water-drought conversion process by measuring the upper and lower soil enzyme activity found that water-drought mode invertase activity showed the upper was higher than the lower layers, and the same with urease activity. |
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