BAU Researchers' IoT Onion Storage Cuts Weight Loss and Raises Marketable Share in Trial

Researchers at Bangladesh Agricultural University (BAU) have built an Internet of Things (IoT) based automated onion storage system to reduce losses from rotting, sprouting and weight loss during storage. In the onion season, prices fall and farmers often cannot recover production costs. When they store onions hoping for higher prices, lack of proper storage leads to rotting, sprouting and weight loss, leaving them at a loss.

In trials, the technology reduced weight loss and increased the share of marketable onions. According to the researchers, a system with a capacity of about 500 kilograms of onions would cost an estimated 25,000 taka to build and install. In experimental use, it showed the potential to reduce storage losses by 15 to 16 percent. The system can also be built for storing up to 1,000 kilograms if needed.

The study, titled Development and Evaluation of a Low-Cost IoT-Assisted Onion Storage System for Reducing Postharvest Losses in Bangladesh, was published on August 26, 2026 in the Journal of Food Process Engineering.

The research team was led by Professor Md Rostam Ali of BAU's Department of Agricultural Power and Machinery. The other members were postgraduate students Nafis Sadik Sayem and Sagar Chowdhury and undergraduate students M. Rahat Mia, Anisur Rahman and Al Amin. The research was funded by the Bangladesh Agricultural University Research System and the University Grants Commission (UGC).

The system uses sensors to measure temperature and humidity inside the storage room. A gas sensor can detect gases associated with rotting. A microcontroller collects and analyses environmental data and can switch a fan on or off as needed, making it possible to control air circulation inside the storage room.

It is not an air-conditioned system. Its work is to improve the storage environment by controlling air circulation based on sensor data. In trials, the IoT system kept temperature between 18.81 and 28.17 degrees Celsius and relative humidity between 54.32 and 82.60 percent, with greater environmental stability than conventional farmer-level storage.

Professor Md Rostam Ali said it is essential to monitor changes in temperature, humidity and air circulation during onion storage. If these factors are out of control, onions lose weight, sprout and rot. The aim of the research, he said, was to reduce those losses through relatively low-cost environmental monitoring and air circulation control.

In the study, 134 kilograms of Murikata variety onions were stored for about 80 days to compare the IoT system with the conventional method. Total weight loss under the conventional method was 27.27 percent. Under the new system it fell to 19.96 percent, a reduction of 7.31 percentage points.

The marketable share was 68.22 percent under the conventional method and rose to 76.81 percent under the new system, meaning about 8.59 kilograms more marketable onions per 100 kilograms. Loss from sprouting also fell from 1.53 percent to 0.37 percent. For loss from rotting, however, no statistically significant difference was found between the two methods.

The research paper said the gas sensor used to detect rotting showed an average effectiveness of about 85 percent. For every 500 kilograms of onions, the 8.59 percentage point difference means about 43 kilograms more onions could be marketable under the new system. How cost-effective it proves in the long term will depend on the device's durability, how many times a year it is used, and operating costs.

According to Department of Agricultural Extension figures for the 2025-26 fiscal year, the country's onion production target was about 4.264 million tonnes, against annual demand of about 3.5 to 3.6 million tonnes. Even so, about 86,400 tonnes of onions were imported in 2025-26. According to Bangladesh Sangbad Sangstha (BSS), imports in 2024-25 were about 474,000 tonnes. About 25 to 30 percent of onions produced in the country are lost at various stages of storage and marketing.

Lead researcher Professor Md Rostam Ali said the technology's effectiveness needs further improvement and larger-scale testing in real storage conditions. He said they are also testing its effectiveness for potatoes and garlic, and working on a version that can run entirely on solar panels. If results are satisfactory, they plan to introduce it experimentally for farmers and commercial storage centres. With necessary financial and technical support, they hope a field-ready model can be built within one to two years.