Page 166 - Ilmu Tanah Book

The Chemistry and Fertility of Soils under Tropical Weeds 153

organic matter content, Total N, and soil CEC, which also decreased with land-use
conversion from forest to coffee plantation and cultivated land.

Key Questions

1. Explain the two catagories of heavy metals in the soil environment and also their
properties and functions to plants!
2. What are the relations of micronutrient metal elements and their effects on plants?
What are the effects of their excesses and scarce concentrations on plants and other
living things?
3. What is the relation of non-micronutrient metal elements and their effects on plants?
What are the effects of their excesses and scarce concentrations on plant and other
living things?
4. What is heavy metal contamination and pollution in soils? What are their effects on the
living things?
5. How do weeds affect the concentrations and availabilities of micronutrient and non-
micronutrient heavy metals in the soil environment? Explain the chemical reactions
involved in responding to the phenomenon of soil pollution by heavy metals!
6. Explain the various forms of heavy metals in the soil water system and their
relationships!
7. Explain the availabilities of each form of heavy metals to plants!
8. Explain the chemical dynamics of heavy metal in the soil system!!
9. Explain the various chemical reactions involved among all chemical forms of heavy
metals in the soil system!
10. Explain the effects of pH on the concentrations of various forms of heavy metals in the
soil system!
11. Explain the effects of CEC on the concentrations of various forms of heavy metals in the
soil system!
12. Explain the effects of lime and organic matter on the concentrations of various forms of
heavy metals in the soil system!
13. Explain the effects of various soil enzymes on the concentrations of various forms of
heavy metals in the soil system!
14. Explain the effects of pH on the concentration of various forms of heavy metals in the
soil system!
15. Explain the effects of weeds on soil pH and the concentration of various forms of heavy
metals in the soil system!

Abdul Kadir Salam and Nanik Sriyani – 2019