Questions about abiotic and biotic components of soil?

Question

1)Is there a relationship between the colour of the soil and the amount of organic matter? Describe.

2)Soil texture is determined by particle size. How might soil texture affect the growth of plants? Which soil texture would be the best for optimal plant growth? Explain.

3)Explain how the organic content might affect the moisture content.

4)Soils with a low pH are detrimental for plant growth. What could be done to neutralize acidic soils? (i.e. neutralizing acidified lakes)

Answer 1

1. Organic matter makes soil darker.

2. Soil with clay is the best. Clay retains water and nutrients and has a good capacity for cation exchange. If there is too much clay though, it may cause waterlogging, which reduces the amount of air in the soil. This is not good for crops.

3. The more the organic content, the more water the soil can retain. That is the main reason swamps are swampy."

4. Applying fertiliser containing lime (CaCo3) reduces acidity and increases overall soil ferility. Lime should not be added to soil where legumes are planted though.

Answer 2

1. Organic matter tends to lower the value and chroma of soil. It also gives it more of a brown hue.

2. The best texture would have clay in it. Clay holds water and nutrients well. It also has the best cation exchange capacity. In certain cases it can hold too much water, not good for plants.

3. Don't know.

4. Add lime (CaCo3)