| This article make sampling survey of the winter and summer pastures of Moraceae prairie in Xiahe county,Along the middle of winter and summer pastures from low altitude to high altitude select two transects. Arranged in a kind of online sample area every65m. Samples are0～20cm soil samples mixed multi-point. There are380items were sampled, winter and summer pastures were158and222.The main research results are as follows:1. Winter pastures mean comparison results, the average winter pastures were organic carbon42.2g/kg, underground biomass1.57kg/m2, inorganic nitrogen31.0mg/kg, available phosphorus2.9mg/kg, TN3.51g/kg, total phosphorus0.77g/kg; summer pastures were mean organic carbon67.6g/kg, underground biomass2.95kg/m2, inorganic nitrogen24.5mg/kg, available phosphorus2.7mg/kg, TN4.84g/kg, total phosphorus0.89g/kg. Which inorganic nitrogen and available phosphorus content in winter than in summer pasture pasture, and below-ground biomass, organic carbon and total nitrogen summer pastures, total phosphorus than in winter pastures. But whether it is winter or summer pasture pasture, soil total phosphorus and available phosphorus levels were very low, this may be an important cause of lower local grassland productivity.2.After correlation analysis, we find that the organic carbon, total nitrogen and total phosphorus in winter and summer pastures have positive correlation and negative correlation with the elevation respectively. Organic carbon will vary with changes in below-ground biomass changes. The total nitrogen, total phosphorus in organic form most in the form of the organic matter present. So they will change with the change of organic carbon and the same. Inorganic nitrogen and available phosphorus mostly negatively correlated with altitude. Because as the altitude increases, the temperature decrease, and ability of soil mineralization recede, leading to the content of effective state of the soil nutrient of soil decrease. |
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