Soil under biologist`s magnifying glass A project for second-year high school students

1. Soil under biologist`s magnifying glass A project for second-year high school students Mirosława Przeworowska-Kawala II Liceum Ogólnokształcące, Chrzanów, Poland mirkap53@gmail.com According to the binding Syllabus Base for Biology, 4th educational stage, extended level, a student: “(...) plans, carries out and keeps a record of biological observations and experiences, formulates research problems, constructs hypotheses(...)” Completion of the core curriculum using the method of project develops the following abilities: planning the experiences, formulation of hypothesis and conclusions, team work, conducting discussions, comparison of observation results. Description of the project: soil as the earthworms` habitat, team work, duration - 14 days. Research problem: Is the soil pH affected by the presence of earthworms? Hypothesis: the presence of earthworms increases the soil pH Description of the experience: 2 jars of 1 litre capacity were filled with soil (650cm³) and the same amount of water. Then, the soil and water were mixed by shaking, a test paper was immersed in it and the pH of the soil was measured – the reaction was acidic. The control sample was a jar without earthworms. The research sample was a jar with 4 earthworms. Both jars were placed in a shady spot with access to air and every three days the soil was watered with the same amount of water. After 11 days the soil pH was alkaline. Conclusion: the presence of earthworms increases the soil pH. These animals have calciferous glands whose secretion neutralizes the acidic pH of the soil. b) Research problem:Do the earthworms affect the volume of the soil? Hypothesis: the presence of earthworms increases the volume of the soil Description of the experience: 2 jars of 1 litre capacity were filled with soil - 650 cm ³ and watered with the same amount of water.The jar without earthworms was the control sample. The research sample was the jar which contained 4 earthworms. Both jars were placed in a shady spot with access to air and every three days they were watered with the same amount of water. After a few days, some narrow tunnels were noticed on the walls of the vessel and the level of the soil was raised. The volume of the soil was increased by 45cm³. Conclusion: the presence of earthworms in the soil increased its volume. The earthworms make tunnels in the soil causing its aeration, which also increases the volume of the soil. Conclusion: the substance of the research work was evaluated student`s task charts were proposed with sample school-leaving exam tasks the students` commitment was noticeable conclusions were presented the experiences were presented in the classroom http://bip.men.gov.pl/men_bip/akty_prawne/rozporzadzenie_20081223_zal_2.pdf