Development of a Monitoring System to Assess the Internal Environment of Bagged Grain in Storage

HighlightsA temperature and relative humidity monitoring system for bagged grain was developed.Continuous monitoring of condition of bagged corn and paddy was done for four months.Temperature and relative humidity within bagged grain followed the ambient conditions.Equilibrium moisture content of the stored grain increased by 1.2% during storage.Abstract.Most farmers in African countries produce small amounts of grain per season and use polypropylene bags for grain storage. Little published information is available on the temperature and moisture change of bagged grain even though high losses are observed. Commercially available moisture meters are expensive and not suitable for providing real-time information on the condition of bagged grain. A monitoring system was developed to assess the internal environment of bagged grain stored in warehouses. The system has eight on-board integrated temperature and relative humidity sensors connected to a custom Arduino-based data acquisition system which recorded a time stamp, temperature, and relative humidity onto a microSD card. Four units were deployed in two warehouses in Nigeria from 3 May 2019 to 9 September 2019. There were 54 bags of corn in Ilorin, and 4000 bags of paddy rice in Tede. Average monthly temperatures recorded at various locations in the warehouse were significantly different (p<0.05). The errors in temperature and relative humidity measurement were 0.2°C and 3.7%, respectively. Equilibrium moisture content of bagged corn and paddy increased by 1.1 and 1.2 percentage points (wet basis), respectively. Data acquired by the system can be used to monitor the condition of bagged grain and detect potential spoilage. This system would help warehouse managers make informed decisions to reduce storage losses. Keywords: EMC, Grain bag storage, Loss management, Moisture, Resilience, Temperature.