Thành phần và vai trò của đất

Soil is formed from the impact of what factors?

• temperature, rain and wind

• Water, creatures and air

• rain and creatures

• Temperature, water, air, wind and rain

The phenomenon of bubbling when dropping soil into water shows which component the soil contains?

• water

• air

• minerals

• humus

When heating soil in a test tube, the appearance of small water droplets sticking to the tube wall indicates what?

• Soil contains minerals.

• Soil contains humus.

• Soil contains water.

• Soil contains air

What components are found in soil?

• Minerals, organic matter, air, water
  

• 
  Rocks, humus, air, water
  

• 
  Invertebrates, minerals
  

• 
  Chlorophyll, nutrients, hydrogen gas

What substances do plant roots take from the soil to live and grow?

• Minerals, humus, air.

• Water, air, nutrients

• Minerals, water, air.

• Minerals, humus, water, air.

What type of soil is suitable for growing industrial crops such as rubber, coffee, and pepper?

• alluvial soil

• basalt soil

• clay

• loam soil

What effect does tillage have on soil?

• Increases minerals and humus in the soil.

• Helps loosen soil and increase air in the soil.

• Helps soil retain water better.

• Increase nutrients for plants.