Increasing the level of water table can help in slowing down global warming, boost crop yields and preserve peat soils in the UK, according to a new study. The research, led by scientists from the University of Sheffield in the UK, found increasing the level below which the ground is saturated with water – known as the water table – in radish fields by 20 centimeters not only reduced soil carbon dioxide emissions, but also improved the growth of crops.
Around a third of greenhouse gases released are through agriculture. Reducing this is critical in order to slow down climate change, however, the world is facing a global shortage of food and agricultural land is a precious resource – adding to the challenge of food security.
A significant proportion of the UK’s farming takes place on drained peat lands, which are some of the most productive soils for commercial agriculture. Draining naturally flooded peat lands, which are organically rich, triggers the carbon to oxide and release carbon dioxide into the atmosphere.
Donatella Zona, senior author of the study from the University of Sheffield’s Department of Animal and Plant Sciences, said: “It is estimated that in 30 years’ time the world’s population will reach 10 billion so it is vital that any means of reducing greenhouse gas emissions do not impact negatively on global food security”.
“We are losing our peat soils in the UK at a fast rate, and we need to find solutions to decrease this loss if we want to preserve our food security. In this study, we investigated the effects of water table levels, elevated carbon-di-oxide and agricultural production on greenhouse gas fluctuations and the crop productivity of radishes which are one of the most economically important fenland crops,” Zona said.
The international team of researchers from the universities of Sheffield, Exeter, Leicester and San Diego, raised the water table from 30 cm to 50 cm in agricultural peat soil collected from the Norfolk Fens – one of the UK’s largest lowland peat lands under intensive cultivation.
Zona added: “Flooding peat land would be too extreme and damage crops, but increasing the water level by just 20 centimeters maintains current food production – or as shown in our study even increases it – while at the same time reducing carbon oxidation and emissions”.
The findings, published in the journal Science of the Total Environment, showed elevating the water table increased the average uptake of the carbon-di-oxide.
Professor Walter Oechel, of the University of Exeter, said: “This is very important in a time of global warming, when reducing greenhouse emissions is a global priority”.