24 February 2022

Artificial intelligence can reduce fertilizer use, UK researchers say

Artificial intelligence allows to predict the trend of nitrogen levels in soil, avoiding fertilizer overuse and related environmental damage according to Imperial College London

by Matteo Cavallito

Fertilizer usage is crucial for the improvement of soil yield. But excessive fertilization can also cause serious problems to land health. Using the right amount of product at the right time is therefore a primary mission for farmers. Luckily, today they can rely on growing technological support.

The latest example comes from the United Kingdom, where scientists at Imperial College London have developed a new predictive testing tool. “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,” explained Max Grell, a researcher in the London university’s Department of Bioengineering. “This could let them fine-tune fertilization to the specific needs of the soil and crops.”

Predicting nitrogen levels with artificial intelligence

Scientists have developed a mathematical model that can be used to process data collected by a special soil sensor. The instrument, called chemPEGS, or “chemically functionalized paper-based electrical gas sensor,” measures ammonium levels. Or the basic chemical that is converted into nitrites (NO2) and nitrates (NO3) by soil bacteria.

The application of artificial intelligence – and machine learning in particular – allows data on weather conditions, fertilization time, acidity level and soil conductivity to be used to predict nitrogen levels over the next 12 days. Thus identifying the optimal time for fertilization.

Nitrogenous soil nutrients, says the study published last December in the journal Nature, “can be determined and predicted with enough accuracy to forecast the impact of climate on fertilization planning and to tune timing for crop requirements, reducing overfertilization while improving crop yields.”

A resource against fertilizer overuse

Reducing nitrogen-based fertilizers is crucial. According to the authors, their use has increased by 600% in the last half century, making 12% of the once arable land unusable. Recently, a report produced by UNEP (UN Environment Agency) in cooperation with FAO and WHO pointed out the main problems associated with the practice. The list includes “nutrient losses to the environment and drinking water contamination.” Some fertilizers “also impact human lives as a result of unsafe storage practices.”

Imperial College researchers also emphasize the climate impact of nitrous oxide, “a greenhouse gas 300 times more potent than carbon dioxide that contributes to the climate crisis”. Fertilizers, they say, “can also be washed by rain into waterways where it deprives aquatic life of oxygen, leading to algal blooms and reduced biodiversity.”

Soil tests are the answer

Finally, the researchers’ findings further promote the importance of soil tests, which have been attracting increasing attention in recent times. Fertilizers skyrocketing price, which is part of the current commodity boom, is crucial. A proper survey of soil properties, in fact, represents an increasing economic opportunity, according to Greg LaBarge, an expert at Ohio State University and co-author of some recent guidelines on land testing.

For technology support, today, it’s just a matter of “when”. The chemPEGS sensors and associated data analysis program are currently in the prototype stage. Their commercialization, the researchers explained, is expected to take a minimum of three to a maximum of five years.