| Chinese apple orchards are mostly distributed in the hilly slope lands. Where the content of soil organic matter is low, especially a series of unreasonable soil management measures such as organic fertilizer deficit and excessive application of chemical fertilizer year after year, which resulted in declining of soil fertility, yields and fruit quality. The healthy development of apple industry was restricted seriously. In this study, the dynamic change of SOM, synthesis and decomposition of organic matter, soil microbial population structure, soil physical and chemical properties and soil enzymes activities of orchard soil, field soil and undisturbed soil from same parent soil material were compared to discuss the change characteristics of these factors under different cultivation mode, find the differences of soil system organification process of different land use pattern and analyze the core of power factor. Soil environment was regulated purposefully by artificial measures in order to identify the response mechanism of orchard soil on the artificial control measures. The science and disadvantages of existing organic orchard soil management system were evaluated from the perspective of organic matter behavior. The technology strategy orchard soil fertility were put forward, which provide theoretical and technical support for apple orchard soil management in northern Bohai Bay.The main results were as follows:1.The effect of different land use pattern on soil system organification process showed that:The soil invertase,β-glucosidase and neutral phosphatase activity significantly affected by different land use patterns, while the cellulase and urease activities did not reach a significant level. Soil enzyme activities were decreased with soil depth increasing, the order of variation along soil depth was natural soil>orchard orchard>field soil. Orchard soil organic matter and N, P, K content ranged between field soil and natural soil, the total potassium content of orchard soil was higher than that in farmland and natural soil, potassium content of0-10cm layer in orchards soil was higher than the other two land use patterns. Spatial distributions of microbes in soil were significantly affected by the mode of land use in orchards. Richness index (S) and diversity index (H) of orchard soil microbes were significantly higher than that of field soil and natural soil in0to10centimeter topsoil. It was found that carbohydrate and polymers carbon are the main carbon source to find the functional differentiation of soil microbial communities under different land use patterns Soil organic carbon (SOC) content and humus fractions HA and HM was highest in farmland soil and lowest in undisturbed soil, while the distribution of the FA in different soil layers was quite different. Cellulase and urease had extremely significantly positive correlation with soil total potassium. Sucrase had extremely significantly positive correlation with soil total nitrogen, available nitrogen, total phosphorus, available phosphorus and available potassium. β-glucosidase had extremely significantly positive correlation with available nitrogen, while had significantly positive correlation with total nitrogen, total potassium, available potassium. Soil organic carbon had extremely significantly positive correlation with total nitrogen, while had significant positive correlation with available nitrogen, total phosphorus, available potassium. Humic had significant positive correlation with soil total nitrogen, available nitrogen, total phosphorus, available potassium.2. The effect of different soil management on soil system organification process showed that:Covering branches and weeds improved the apple orchard soil nutrient levels and the quality of carbon pools, however, covering branches had more contribution than covering weeds to the stability of the soil carbon pool. Compared with crop stalks and weeds, branch treatment significantly increased the content of soil organic carbon and humin, which provided a strong guarantee for the realization of material circulation inside orchards.3. The effect of different soil organic materials on soil system organification process in northern Bohai Bay showed that:the cellulose, invertase, catalase activity and nitrogen, available phosphorus and potassium content were highest in sheep dung treatment, followed by rice shell treatment. Phosphatase activities of rice husk were the highest. The results of same treatment in indoor cultivation, processing and field trials pot were varied. For pot experiment, total nitrogen and total phosphorus content of soybean straw treatment was the highest, while the content of organic matter were higher in rice husk. For field trials, the nitrogen content of corn stalk treatment were the highest, total P content of rice husk treatment was the highest, total K content of soybean treatment was the highest. Different organic materials significantly increased nutrients accumulation level in different organs of apple plant. Among them, sheep dung treatment had the best effect on nutrients accumulation, followed by rice husk treatment.The effect of adding small organic molecules and earthworms on soil system organification process sin northern Bohai Bay showed that:After adding the small molecules of glucose and earthworm, microbial functional diversity, the activity of soil cellulase, invertase and β-glucosidase significantly increased, at the same time, improved the activity and stability of the soil carbon pool. It could make a contribution to increasing the soil humic content and microbial functional diversity while adding urea and glucose at the same time. Average Well Color Development (AWCD) values were significantly affected by small molecular organic compounds and numbers of earthworms. It was found that the differentiations of carbon utilization were mainly caused by carbohydrate and polymers carbon. The addition of glucose provided more available carbon sources for the soil microbes, as a result, the microbial functional diversity also had significant increase.The earthworm activities accelerated the soil organic pool transformation, and improved the activity and stability of the soil carbon pool. Small organic molecules and numbers of earthworms had a significant effect on the growing of Malus Baccata Borkh.. The vigor of Malus Baccata Borkh. was the weakest after adding only the glucose treatment, at the same time, photosynthetic performance and nitrogen content was degraded, while, at the same time, adding urea could improve plant photosynthetic capacity, and promote the growth of Malus Baccata Borkh.. Earthworm activities increased utilization of plants for moisture and nutrients (N, P, and K), promoted the increasing of plant height, leaf number and stem diameter. |
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