Academic Goal: Students will analyze local soil samples and calculate the C.E.U's (Cation-Exchange-Unit) and pH.
Essential Question: How does the soil quality impact the nutritional quality of food crops?
Lab Experiment: Inquiry questions: Hypothesize about the CEU's present in local soil samples. Using local soil samples students will quantify the amount of CEU's present.
Cation exchange capacity
Cation exchange capacity (CEC) is a measure of the total amount of exchangeable cations (positively charged ions) a soil can adsorb. Nutrient cations in the soil include positively charged ions such as calcium (Ca+2), magnesium (Mg+2), potassium (K+), sodium (Na+) and hydrogen (H+). In soil tests, CEC is reported in milliequivalents (meq) per 100 grams of soil. The exchangeable cations in the soil are in equilibrium with those in the soil solution (water in the soil). As plants remove nutrients (cations) from the soil solution, they are replenished from the adsorbed cations, which are then available for plant uptake (Figure 4). http://extension.missouri.edu/p/MG4
Cation exchange capacity (CEC) is a measure of the total amount of exchangeable cations (positively charged ions) a soil can adsorb. Nutrient cations in the soil include positively charged ions such as calcium (Ca+2), magnesium (Mg+2), potassium (K+), sodium (Na+) and hydrogen (H+). In soil tests, CEC is reported in milliequivalents (meq) per 100 grams of soil. The exchangeable cations in the soil are in equilibrium with those in the soil solution (water in the soil). As plants remove nutrients (cations) from the soil solution, they are replenished from the adsorbed cations, which are then available for plant uptake (Figure 4). http://extension.missouri.edu/p/MG4
HOMEWORK: Learning Goal II: (Please refer to portfolio sheet on assignment. Topics to choose from include: Soil ecology, soil habitat, soil mycorrhizae desert habitats, soil restoration, soil pollution. EBSCO SITE: http://pioneer.uen.org/k12/
Lab Summary: CEU and Soil pH Lab
