6 & 7. biological and chemical properties of soil done.docx

Biological and Chemical Properties of Soil There are two chemical properties that are important in determining the characteristics of soil. Cation exchange capacity is where one ion (e.g. calcium) is replacing another ion (e.g. hydrogen). The soil joins (clay and humus) are the soil particles with t...

Biological and Chemical Properties of Soil There are two chemical properties that are important in determining the characteristics of soil. Cation exchange capacity is where one ion (e.g. calcium) is replacing another ion (e.g. hydrogen). The soil joins (clay and humus) are the soil particles with the greatest level of cation exchange. PH is a measure on the amount of the hydrogen ions in a solution. The soil pH effects crop growth and the activity of living organisms in the soil. 0-6 ranges is acidic 7 is neutral 8-14 is alkaline or base Biological Properties of Organisms in soil The term soil Biomass is the total amount of living material in a habitat this refers to all the plants and animals in a soil such as worms, insects, bacteria when they die they turn into organic matter Humification is the process by which soil organic matter is changed into humus. Macro-organisms such as earthworm or bacteria convert soil organic matter into humus. Fungi also change soil organic matter to humus. Role of organisms in the Carbon Cycle such as plants remove carbon for photosynthesis & return it through respiration. livestock get carbon by eating plants and release it through respiration. Nutrient recycling is caused by Nitrogen Fixation this is when nitrogen gas are turned into nitrates. Plants such as clover, have tiny nodules in their roots this is where live bacteria called nitrogen fixing bacteria, which converts nitrogen gas into nitrates. Nitrification is the conversion of ammonia to nitrite and nitrite to nitrate. Denitrification is the conversion of nitrates to nitrogen gas.