Composting Yard and Garden Waste

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Lincoln Middle School has an active school garden, and physical science students realized they could help “green” their school by finding an environmentally responsible way to handle garden waste. With guidance from community composting experts, students researched and constructed a 4-bin composting system and educated their school community about its importance.

While gathering data in the fall on how much plant waste had accumulated in the garden, students inquired about why there was no compost system. Recognizing that need had not yet been met, they wanted to address it.

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Students invited the city’s Solid Waste Management Division Coordinator to visit and explain the best methods for composting plant matter. They also visited a local waste management facility and researched online to learn more about the science of composting and the environmental effects of throwing plant matter in the trash.

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Students wanted to pursue composting, but still needed to determine which method would be most effective. They interviewed composting practitioners and calculated the plant mass from different garden plots to determine the school’s total annual plant mass. Their data showed that the system would need to handle up to 50 pounds annually, helping eliminate small-scale composting units. Students voted to construct a 3-stage composting system, built from recycled wooden pallets.

New insights about plant cycles and composting were linked routinely to their curriculum units on the Conservation of Matter/data analysis. For both standards, the teacher completed a CTS and used rubrics to grade content-related assignments. In formative assessments, students received their score and written or verbal comments to help them improve, even if they already met the standard.

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Students outlined needed tasks (such as siting, constructing and planning the establishment and maintenance of the system), and teamed up to complete them. Some students did further data analysis calculating how much compost starter material was needed, and what volume of leaves would be needed to achieve the ideal carbon-nitrogen ratio.

Students documented their progress on a chart in the classroom, and each class session began with a review of chart notes. Students succeeded in building and filling the compost bins before the first snowfall. To inform others of their progress, students made daily announcements and a video on the school Website (helping teach others how to construct their own compost bins). They celebrated their accomplishments with a pizza party where they watched the edited version of their video for the first time and saw a slide show documenting the project.