A team from Kansas State University and the US Department of Agriculture’s Agricultural Research Service (ARS) have designed a hand-held sensing unit or post-harvest loss moisture meter to help farmers check the moisture level in their stored grain or feed.
The project, which is a part of work being done by the Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, is being done through USAID, said Paul Armstrong, agricultural engineer with the ARS Center for Grain and Animal Health Research.
The initiative started with the aim of finding an efficient way to monitor moisture content for producers in underdeveloped countries.
The hand-held unit is based on grain storage bin sensors technology that gauges humidity and temperature levels to establish moisture content, he said.
“We came up with a meter that can be used with bagged grain,” he told FeedNavigator.
The tool eventually designed includes a three-foot long tube containing a sensor that connects to a hand-held meter that displays the estimated moisture content, he said. “The whole idea was to make it open source,” he added.
“There are other methods that are mostly sample and measure, where you pull out a sample,” said Armstrong. “[They] work quite well, but they require a lot of calibration.”
Monitoring moisture and in-feed use
Work on the initial sensing unit started in about 2014 and the USAID project is set to run through the end of 2018, said Armstrong. However, there are efforts underway to potentially extend the timeline.
The group has mostly been focused on work with corn and rice, he said. The device also can be used with feed grains and ground feed.
“Sometimes you want to probe the moisture level not at the surface, but as far as you can push the probe into the grain,” he said. The design of the probe makes that sort of check easy to do.
For corn, it is specific within about .5%, said Armstrong. If the grain has a moisture level higher than 15%, the device is less accurate – but then the feed grain is too wet to store.
Related parts of the project look at training farmers on the drying process, insect control, fumigation and storage practices, he said. “If they keep the storage conditions under control and the grain goes in dry they should be fine,” he added.
Some of the units have been in use in countries including Ghana, Bangladesh, Ethiopia, Nigeria and Kenya, said Armstrong.
One goal in allowing farmers a simple and quick way to measure the water level in stored grain is that it can help prevent damage to the grain or feed, he said. “The primary concern would be mycotoxin development – aflatoxin is more specific, and it’s a toxin that has caused a lot of problems,” he added.
If grain is found to be too wet there is still the potential that it could be further dried and prevent toxin damage, he said. However, the best option to would be to ensure that the grain is properly dried when it is initially stored.
“Drying is primarily done [with] sun drying – we’re trying to get better drying methods,” he said. “If they have rainy weather they can’t get it dry and in some places their harvest season coincides with their rainy season – that’s always a big problem.”
The current system can cost about $70 a unit to construct using off-the-shelf parts, said Armstrong.
“We’re doing a second generation development on that to make it more inexpensive and also possibly working with people in Ghana trying to set it up for manufacturing there,” he said. Currently the price is high for many of the farmers the group meets.
The primary focus in the second-generation device would be to reduce the cost, he said. However, they also are focusing on making them able to connect to a smart phone – meaning the sensor unit would not need its own display screen.
“We’re trying to get the cost down as much as possible,” said Armstrong. “We’re focusing on the electronics to get it cheaper.”
The group is still in the tuning phase for the updated sensor unit, he said. Efforts are also ongoing to establish what a workable price point would be.
“Right now we have a contact at a university in Ghana who is making the first generation,” he said. “And who supplying about 100 units, and he has customers for those [like] the Ghana Grain Council and various NGOs [non-governmental organizations] and some groups that will purchase them.”