兰州市中心城区道路绿地土壤pH和养分特征

为掌握兰州中心城区道路绿地土壤pH和养分状况,找出主要限制因子并提出解决办法,以行道树周边土壤为研究对象,分0?30和30?60 cm两个土层,根据土壤有无植被覆盖,分裸露和植被覆盖两组采样,运用分组回归方法分析土壤pH与土壤肥力间相关性,研究不同pH组道路绿地土壤养分的基本状况.结果表明:1)土壤pH在7.91～9....

Study on soil pH and nutrients in a roadside green belt in a central urban area of Lanzhou

To determine the pH and nutrient status in roadside greenbelt soil in a central urban area of Lanzhou,uncover the main limiting factors,and propose solutions,the soil around street trees,which was divided into 0?30 cm and 30?60 cm layers,were sampled.Depending on whether the soil was covered by vegetation,the samples were further divided into bare and vegetation-covered groups.The relationship between soil pH and soil nutrients was analyzed using the group regression method.The soil pH ranged from 7.91 to 9.39,with an average value of 8.49,and was generally high,with 33.42%and 0.47%of the soil being strongly and extremely alkaline,respectively.Soil organic matter content ranged from 5.30 to 47.80 g·kg^?1,with an average value of 18.29 g·kg^?1,and 37.64%and 21.77%of the soil were relatively and seriously deficient,respectively.Soil alkali-hydrolyzable nitrogen content ranged from 5.24 to 167.55 mg·kg^?1,with an average value of 48.54 mg·kg^?1,and 35.68%and 5.95%of the soil were relatively and seriously deficient,respectively.Soil available phosphorus content ranged from 4.68 to 184.46 mg·kg^?1,with an average value of 45.66 mg·kg^?1,and 19.58%and 1.67%of the soil were relatively and seriously deficient,respectively.Soil available potassium content ranged from 72.35 to 449.64 mg·kg^?1,with an average value of 177.60 mg·kg^?1,and was not deficient.Organic matter,available nitrogen,available phosphorus,and available potassium contents in the 0?30 cm layer of bare soil were significantly higher than those in the 30?60 cm soil layer.Additionally,available nitrogen and available potassium contents in the 0?30 cm soil layer covered by vegetation were significantly higher than those in the 30?60 cm soil layer.The results of correlation analysis showed that organic matter,alkali-hydrolyzable nitrogen,and available phosphorus contents were negatively correlated with soil pH,and that high pH was an important factor that limited the exertion of soil nutrients in the Lanzhou road greenbelt.Vegetation coverage significantly decreased soil pH and significantly increased the contents of organic matter,alkali-hydrolyzable nitrogen,and available phosphorus.Therefore,vegetation coverage on a bare surface can effectively improve the main problems that exist in roadside green belt soil.