Awards: Second Prize of 2018 State Scientific and Technological Progress Award

Lead researchers: Xu Minggang, Xu Renkou, Zhou Shiwei, Ma Changbao, Li Jiuyu, Wen Shilin, Lu Yanhong, Peng Chunrui, Zhang Qing, and Zhan Shaojun

By conducting nearly 30 years of network research based on 110 long-term monitoring test sites in China’s six typical provinces, researchers in the project have clarified for the first time the spatiotemporal evolution of soil acidification in red soil farmland across China, and developed an early warning method for estimating and predicting soil acidification rates. In the research, they classified China’s acidified farmland into four categories: extremely strongly acidified, strongly acidified, moderately acidified and weakly acidified, and identified their area and distribution.

In addition, researchers confirmed and quantified the role of nitrogen fertilizer in farmland soil acidification and the contribution of organic fertilizer to soil acidification prevention and control. They developed a key technology of soil acidification prevention and control that reduces chemical fertilizer and increases organic fertilizer. The research also proposed an acid damage threshold for staple crops, determined lime requirements and application intervals, and developed a key technology for remediation of soil acidification by lime substances with strong operability. It presents a comprehensive technology model for regional farmland acidification reduction.

The project helped reduce farmland soil acidity and improve soil fertility. It provided a technical model for the classification and prevention and control of acidic soil in China, promoted the research and development of acidic soil conditioners and other products, and sped up the promotion and application of regional farmland acidification prevention and control technologies.

The research results have been used in 72.13 million hectares over three years, generating an additional economic benefit of 12.58 billion yuan ($1.897 billion). Researchers obtained 17 invention patents for the project results and formulated two industrial standards. As many as 171 papers, including 64 SCI journal papers, and seven books were published.