A group of Chinese scientists say they have found a way for farmers to grow more food without increasing the toll on the already fragile environment.
Researchers said they had tested "smart" agricultural management, using scientific knowledge to better match local soils and climate and optimise nutrient requirements, in more than 150 field experiments in major production areas for rice, wheat and maize in the past five years.
Farmers could significantly boost yields and cut their reliance on fertiliser if the techniques were adopted, they said in the study, published yesterday on the website of scientific journal Nature.
Zhang Fusuo, a professor at China Agricultural University who led the team, said that although grain production had increased, harvests relied on large amounts of fertiliser, and the approach was unsustainable.
"Our research proves that we can reduce environmental costs when we strive to increase crop yields persistently and ensure food security," he said yesterday.
"It depicts a blueprint for Chinese farming in the future. But there will surely be a long way to go before it's implemented by the millions of farmers."
China is the world's biggest producer and consumer of fertiliser, making and using about a third of the global total, according to official figures.
But research by the Ministry of Agriculture last year showed it was not being used effectively. The average utilisation rate of nitrogen fertiliser, the most common type, for the three major crops is just 33 per cent. The rest pollutes the soil and water.
The team compared yields using four farming methods.
One technique was to grow cereals according to the practice of local farmers, and the second was a tweaked, or "improved", version of the same method.
The third way sought to maximise yield without regard for the environment, which often meant dousing fields with nitrogen fertiliser.
The fourth approach used a system called integrated soil-crop system management. It matches strains to local soils and climate, applies more precise dates for when to sow and at what density, and uses fertiliser more efficiently.
The highest yield came from the third option, and was close to the yields achieved by intensive farms in the United States and Germany. But the smart farming technique also did very well, with yields typically 97-99 per cent of the maximum yield but achieved at far less cost to the environment, researchers said.
Production would surpass demand for food for human consumption by 2030 if farmers could achieve yields of 80 per cent of those obtained in the experiments and if the acreage under crops remained the same as in 2012.
Zheng Fengtian, a researcher specialising in agriculture at Renmin University, said it had been estimated that output would not be affected if farmers cut their fertiliser use by half. "If we follow the suggested ways [in the report] on a large scale, it will help ease pollution a lot," he said.
Zhang said China would need about 650 million tonnes of grain annually by 2030.