Low-cost AI soil sensors could help reduce fertiliser use

23-12-2021 | Crop solutions | News

The study identifies how this new low-cost solution could help growers yield maximum crops with minimal fertilisation. - Photo: Canva

Smart sensing technology to help farmers use fertiliser more effectively and reduce environmental damage has been created by bioengineers at Imperial College London.

The technology, which is described in Nature Food, could help growers work out the best time to use fertiliser on their crops and how much is needed, considering factors like the weather and soil condition.

Sensor measures levels of ammonium in soil

The sensor, named chemically functionalised paper-based electrical gas sensor (chemPEGS), measures levels of ammonium in soil – the compound that is converted to nitrites and nitrates by soil bacteria. Using a type of AI called machine learning, it combines this with weather data, time since fertilisation, pH, and soil conductivity measurements. It uses these data to predict how much total nitrogen the soil has now and how much it will have up to 12 days in the future, to predict the optimum time for fertilisation.

Yield maximum crops with minimal fertilisation

The study identifies how this new low-cost solution could help growers yield maximum crops with minimal fertilisation, particularly for fertiliser-thirsty crops like wheat. The technology could simultaneously reduce growers’ expenses and environmental harm from nitrogen-based fertilisers – the most widely used fertiliser type.

The researchers expect chemPEGS and associated AI technology, which are currently in prototype stage, to be available for commercialisation in three to five years with more testing and manufacturing standardisation.

_{Text continues underneath video}

Overfertilisation

According to Imperial College London, overfertilisation has so far rendered 12 per cent of once-arable land worldwide unusable and the use of nitrogen-based fertiliser has risen by 600 per cent in the last 50 years. However, it is difficult for crop growers to precisely tailor their own fertiliser use: too much and they risk environmental damage and money wastage; too little and they risk poor crop yields.
Lead researcher Dr Max Grell, who co-developed the technology at Imperial College London’s Department of Bioengineering, said: “It’s difficult to overstate the problem of overfertilisation both environmentally and economically. Yields and resulting income are down year by year, and growers don’t currently have the tools they need to combat this.
“Our technology could help to tackle this problem by empowering growers to know how much ammonia and nitrate are currently in soil, and to predict how much there will be in the future based on weather conditions. This could let them fine-tune fertilisation to the specific needs of the soil and crops.”