QF research explores the use of agriculture’s black gold to boost food production

As Qatar ramps up food production, it inherently brings up the question of how the country can efficiently deal with the food waste that will accompany increased agriculture.

Food waste happens at every step of the supply chain – from farms to supermarkets, restaurants, and homes. Most of us are oblivious to the severe environmental consequences of this wastage. A study by the Food and Agriculture Organization of the United Nations report says if food waste were a country, it would rank just behind China and the United States as the third largest emitter of greenhouse gases.

The majority of food waste ends up in landfills, and this is problematic because when food rots, it releases a gas called methane – a powerful greenhouse gas with a 100-year global warming potential, about 25 times that of carbon dioxide (CO2).

In an effort to find a more efficient waste disposal solution, a team of researchers at Qatar Foundation’s (QF’s) Hamad Bin Khalifa University (HBKU), is exploring how food waste and other organic matter can be utilized to produce biochar - also known as agriculture’s black gold due to its charcoal like appearance and great value it adds to the soil. The research is funded by QF’s Qatar National Research Fund (QNRF), and led by Dr. Gordon McKay, Professor of Sustainable Development at HBKU.

“Biochar is a charcoal-like substance that’s produced when agricultural waste, plant matter (leaves, trunks, roots), manure, or other organic material is heated in a zero or low-oxygen environment – a process known as pyrolysis,” said Dr. Hamish Mackey, Associate Professor, College of Science and Engineering, HBKU.

Biochar production is a carbon-negative process, which means that it effectively reduces CO2 in the atmosphere. To put it simply, the waste used for making biochar would release carbon dioxide to the atmosphere if it was left to decompose naturally. Through pyrolysis, its carbon content can be transformed into a stable structure that doesn’t react to oxygen, ultimately reducing carbon dioxide in the atmosphere.

“Two of biochar’s most valued benefits for plant growth are nutrient and water retention. When worked into the soil, biochar can prevent nutrients from leaching out and water from draining out of your soil, making biochar an effective soil amendment,” said Dr. Tareq Al-Ansari, Assistant Professor, College of Science and Engineering, HBKU.

Think of biochar as a carbon-rich sponge. Because of its porous nature, biochar can improve the water retention capacity of soil, allowing plants to have more water available to them for a longer period of time.

Biochar is most effective when it is applied to soils with poor fertility making it especially useful for plants in arid to semiarid environments, regions prone to drought, and areas with limited irrigation capabilities.

“It is more important to note that not all biochars are the same. Their properties depend heavily on the production parameters such as temperature and heating rate. Similarly, their effects vary depending on the kind of soil that is being amended, maximum improvement is seen in sandy soil which is prevalent in Qatar,” said Dr. Mackey.

Preliminary studies performed by the group using biochar produced using local waste cabbage have been very promising. Pot tests were done by adding biochar to sandy soil to investigate the effect of biochar on the growth of basil plants.

Adding only two percent biochar resulted in the doubling of shoot height as well as the number of leaves per plant. It also reduced the uptake of Aluminum – an undesired element by the plant while increasing the uptake of desirable trace metals and salts. The water retention capacity of the soil nearly doubled; this is likely to have a considerable effect on the irrigation needs of the plants.

“The next step is carrying out long-term evapotranspiration tests to estimate the loss of water from both plants and the soil after addition of biochar, this will be key in determining how much real water savings can be realized,” said Dr. Al-Ansari.

The group is expecting installation of a large pilot plant at Education City this year which will allow them to scale up the biochar production capacity and move towards field scale testing, a crucial step before commercialization.

Dr. Mackey said: “Field tests will be conducted over an extended period of time so we have solid data to demonstrate the effects of biochar on the soil as well as the plants and most importantly quantify potential water savings.”

“Food waste is a major issue both in Qatar and globally. Through this project we are laying the groundwork for a circular economy in agriculture wherein we use food waste for regeneration of natural systems and enhanced agricultural productivity,” said Dr. Al-Ansari.