The experimental study on trans-regional soil replacement

Abstract

When people did ecological restoration, it was very difficult to achieve the trans鄄regional soil replacement. Basalt platform is distributed around the Changbai Mountain Nature Reserve. The intrazonality soil ( i.e. baijiang soil, peat soil and meadow soil) in the temperate humid climate zone is developed widely on basalt platform, howerer, the zonality soil such as dark brown earth is rare. The mountain brown coniferous forest soil, baijiang soil, peat soil and meadow soil are not in the same physical geographic zone, and there are significant differences in their physical and chemical properties, thus, it is not easy to complete soil replacement directly. In this zone, we could use the synthesis soil which is artificially synthesized with baijiang soil, peat soil and meadow soil to instead of the mountain brown coniferous forest soil. In this study, the baijiang soil, peat soil and meadow soil in the dark brown soil zone in the temperate broadleaved鄄coniferous mixed forest were used as raw materials, and the mountain brown coniferous forest soil in cold temperate zone in Changbai Mountain Nature Reserve was used as replacement object. Firstly, we completed soil synthesis taking the imitates the natural prototype principle, and then, conducted the experimental research on trans鄄regional soil replacement and plant growth. The results showed that the differences of soils were significant in the distribution of the content of every soil grain size group ( %) , humus layer thickness (10-20 cm) , pH (5.9-7.5) , and the available nitrogen ( N) content (57.8-100.7 g / kg) in the mountain brown coniferous forest soil zone. The limited factors of plant growth were humus layer thickness, pH, and available N content of mountain brown coniferous forest soil. Plant growth condition was better as the humus layer thickness was 40cm, pH was 7.0 and available N content was 80 mg / kg which were the inflection point value of the mountain brown coniferous forest soil limited factors. Therefore, the inflection point value of the mountain brown coniferous forest soil limited factor was a key to synthesis soil, and it was the basis for physical and chemical indicators of synthesis soil. There were more gravel but less silt and clay on surface soil of the mountain brown coniferous forest soil, the soil texture is gravelly