Authors: Yongjiang Wang, Grant Clark, Michael Yongha Boh
Published in: CSBE-SCGAB Technical Conferences » AGM Charlottetown 2022
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Description: Compost hotbeds can release thermal energy to warm the soil and accelerate plant growth. However, current hotbeds have the risk of degrading anaerobically. Additionally, tools for designing a hotbed to supply a specified amount of heat are lacking. A laboratory-scale compost hotbed was constructed with an enhanced aeration system to emulate soil-based plant production in a greenhouse environment. This proof-of-concept system was constructed using a plastic bin (thermal box). The thermal box had a volume of 6.8 L and dimensions of 283×175×138 mm (L×W×H). Gravel, ~1.2 kg, formed an aeration plenum in the bottom of the box. About 2 kg of mixed chicken manure, wheat straw, and food waste were placed over the gravel, followed by a layer of ~1 kg topsoil. The system was replicated thrice and tested for 90 days. Temperature was measured continuously and transmitted via an Arduino® board to a cloud-based data server (ThingSpeak™). The experiment was carried out in a climate-controlled room with an air temperature of 14.9°C (+/-0.7). During the first 7 days, the compost temperature rose from 18.0°C (+/- 0.4) to 24.0°C (+/- 2.5). The gravel temperature rose from 17.5°C (+/- 0.5) to 20.6°C (+/-2.0). The soil temperature rose from 13.4°C (+/- 0.6) to 22.6°C (+/-2.5). The data from this experiment will be used to develop a thermal-dynamic model of the compost hotbed that may be calibrated for the design of larger installations. Hotbeds may then be designed to stabilize air temperature in greenhouses while providing organic crop fertilizer.
Keywords: Compost, hotbed, heat recovery, IoT
Conference name: CSBE/SCGAB 2022 Annual Conference, Charlottetow, PEI, 24-27 July 2022.
Session name: Agricultural Engineering4
Publication type: Presentation
Language 1: en
Rights: Canadian Society for Bioengineering