Acidity top layer of soil

The map with acidity in the top layer of the soil (the upper twenty centimeters) is made by Alterra Wageningen. The acidity or pH is soil characteristic, which is mainly determined by the parent material, the soil-forming processes in the past and the land use. The pH affects the chemical soil fertility and the rootability of the soil profile. The pH in the top layer of sandy soils will gradually decrease under natural conditions. In agricultural areas, this is counteracted by fertilisation with lime.由瓦赫宁根阿尔泰拉（Alterra Wageningen）编制的土壤表层（20厘米上层）酸度分布图数据集，其涉及的土壤酸度即pH值为土壤固有特性，主要由成土母质、既往成土过程与土地利用方式决定。pH值会影响土壤化学肥力与土壤剖面的根系生长适宜性。自然条件下，砂质土壤表层的pH值会逐步降低；在农业生产区域中，施用石灰肥料可抵消这一pH值下降趋势。