Diversifying cropping rotations could help farming systems become sustainable for the long-term thanks to increased yields and improvements to soil health, according to a six-year study.
Researchers in China found that rotating traditional monoculture crops like wheat and maize with cash crops like sweet potato and legumes significantly boosted yields whilst improving farms’ greenhouse gas (GHG) balance sheets.
What’s more, employing a more diverse cropping system improved soil health and soil organic carbon stocks, helping to make farm businesses more environmentally-friendly and profitable.
In a study published in Nature Communications, researchers from China Agricultural University, Hainan University and Wenzhou University described how they ran a series of field experiments in the North China Plain between 2016 and 2022.
The region is one of the most intensively cultivated regions of the world, producing 23% of China’s total cereals, and is typically dominated by double cropping winter wheat, followed by summer maize.
In the trails carried out on farms across the plain, the team assessed different systems based on yields, GHG emissions, soil health and farm incomes.
They found that diversified rotations increased equivalent yields by as much as 38%, reduced nitrous oxide emissions by 39%, and improved farms’ GHG balance by 88%.
Meanwhile, adding legumes into rotations stimulated soil microbial activities, leading to an 8% increase in soil organic carbon stocks and a boost in soil health of 45%.
Professor Kadambot Siddique of the University of Western Australia, who co-authored the study, said the large-scale adoption of diversified cropping systems in the region could increase overall cereal production by almost a third, while farmer incomes could see a 20% boost.
And while the research had focused on China’s North Plain, the findings could be applied to other countries where farmers might see benefits, he said.
“Our findings could guide the North China Plain and similar agro-ecological zones in establishing a more sustainable system to maintain or increase grain and protein production while reducing damage to the environment and soil ecosystems,” he added.
“Agriculture is a net emitter of greenhouse gases however, integrated cropping system developed in this study provide an opportunity towards carbon neutrality while maintaining profitability.
“These results from an intensive food producing region may also provide a guide for countries and regions with similar agricultural environments to follow on an expanded scale.”