Indurated calcic soil horizon that is cemented by a high concentration of calcium carbonate, often comprising 40% by weight of the mineral material, and that is impenetrable to plant roots or to spade digging.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。