Suburbs Of Beijing To Protect The Soil Nitrogen Mineralization Process

More than 100 soil samples are collected to study the course of the soil nitrogen mineralization in Beijing suburb fields by short-term and long-term aerobic incubation experiments with intermittent leaching. It mainly researched as follows: the different courses of the soil nitrogen mineralization in vertical sections, the influence of the soil basic Physical and Chemical characters on the nitrogen mineralization, the influence of the planting time on the nitrogen mineralization courses, the different nitrogen mineralization courses of the soil in protected vegetable fields and open fields, at last the mineralized nitrogen quantity supplied and the optimized mineralization model parameters in protected vegetable fields are confirmed by non-linear regression.The conclusions are as follows: firstly, the quantity of the mineralized nitrogen in Beijing suburb protected vegetable fields is much. The soil mineralized nitrogen weekly and mineralized nitrogen rate daily are falling with incubation time going, but the accumulative mineralized nitrogen is just the opposite.Secondly, the mineralized nitrogen quantity and rate are falling with the depth increasing in soil vertical sections from 0 to 90cm, the same as the ratio of the mineralized nitrogen quantity to total nitrogen and to the organic matter. The differences of the mineralized nitrogen quantity and rate between different vertical sections are enlarging with time going.Thirdly, the relationship of the mineralized nitrogen quantity and the soil basic Physical and Chemical characters is as follows: in short-term aerobic incubation experiments with intermittent leaching, the first is the organic matter, and then is the total nitrogen, the third is the NO3-N and the last is the NH₄⁺-N. The negative relativity of the soil pH value and the mineralized nitrogen is prominent, and the same as that of the accumulative quantity of the mineralized nitrogen in long-term aerobic incubation experiments with intermittent leaching. The relativity of the accumulative mineralized nitrogen quantity and the soil basic Physical and Chemical characters is following: the first is the organic matter, and then is the NH₄⁺-N, the third is the NO₃^- -N and the last is the total nitrogen. The relationship of the mineralized nitrogen quantity and the soil basic Physical and Chemical characters is as above in long-term aerobic incubation experiments with intermittent leaching, but the relationship between the accumulative quantity of themineralized nitrogen and the soil basic Physical and Chemical characters is better than that in...