大部分黑土和褐土属于较高水平，而白浆土、草甸土和棕壤偏低。

The level of available silicon is higher in Black soil and Cinnamon soil, but lower in Albic soil, Meadow soil and Brown earth.

寄主植物存在与否对黑土和白浆土的载菌量有明显的影响，而对风沙土和草甸土影响不大。

Planting host plants significantly influenced the bacterium capacity of soil on black and lessive soils, but less influence on sandy and meadow soils.

对轮作及大豆、玉米、小麦长期连作白浆土中氮含量及有机态氮组分变化进行研究。

The nitrogen contents and nitrogen forms were studied in albic soil with longterm crop rotation and soybean, maize, wheat continuous cropping.

黄河三角洲区为粉土-软土地层结构。

The Yellow River delta is made up of silt and soft soil.

盖(土)盖上或在(植物)上堆土以保护。

To cover or heap (plants) with soil for protection.