Black soils are recognized as the world’s most fertile soils and contribute significantly to global food security. Their high organic matter content also acts as a carbon sink, helping to mitigate climate change by storing CO2 emissions. With an area of one million square kilometers, Northeastern China is home to one of the largest black soil regions worldwide, but serious soil degradation and erosion is putting this precious resource at risk.
Sustainable soil management in the spotlight
From 16 to 18 June, the Sino-German Agricultural Centre (DCZ) invited Chinese and German soil experts to China’s northeastern city of Harbin to discuss sustainable approaches to black soil protection. Jointly organized by DCZ, the Heilongjiang Academy of Agricultural Sciences (HAAS), and the German Embassy in Beijing, the two and a half-day event brought together scientists, business representatives, and practitioners to discuss solutions that can help ensure the fertility and health of one of the region’s most valuable agricultural resources.
Following welcome remarks by Ms. LIN Huifang, Deputy Director General of the Foreign Economic Cooperation Center (FECC) of the Chinese Ministry of Agriculture and Rural Affairs (MARA), German Consul General Mr. Hendrik Barkeling, German Agriculture Counselor Ms. Friederike Dörfler, and representatives from German industry, several keynote speeches delved further into the challenges facing the protection and sustainable use of black soils in China.
Professor OUYANG Zhu from the Institute of Geographic Sciences and Natural Resources Research at the Chinese Academy of Sciences (CAS) presented findings from research his team had conducted around Qiqihar City in Heilongjiang province. To halt the loss of soil organic matter and strengthen the carbon cycle, Professor Ouyang advocated for a closer integration of cropping and animal husbandry. His findings showed that reusing straw as animal feed while converting animal manure into organic fertilizer had positive effects on the soil carbon and nitrogen balance. However, long distances between crop and livestock farms in Heilongjiang Province mean that the links between both farming systems are weak, making nutrient recycling a challenge for local farmers.
Dr. Carsten Hoffman, project manager of the FAIRagro research project at the Leibniz Center for Agricultural Landscape Research (ZALF), highlighted the benefits of data sharing in the fields of soil and agricultural research. Taking the German research projects Bonares and FAIRagro as examples, Dr. Hoffmann shared experiences in creating a freely accessible infrastructure for researchers and the community to share data related to soil, agriculture, and ecology from Germany and the world.
LIU Jie, Director General at the Heilongjiang Academy of Black Soil Conservation and Utilization presented technologies and practices of sustainable black soil management. He showed that the inappropriate use of chemical fertilizer is an important reason for the degradation of black soil. Drawing on randomized field trials conducted by his institute since 1979, Professor LIU argued that chemical fertilizer combined with organic fertilizer is an effective way to improve soil fertility, maintain soil health and increase grain productivity.
Case studies integrate science and practice
In her case study on the Sanjiang Plain region in Heilongjiang Province, Professor WANG Qiuju from the Heilongjiang Academy of Agricultural Sciences presented different types of crop rotations to improve soil fertility as well as a new technology for subsoil fertilization. The technology has been included into MARA’s catalogue of promoted technologies, she explained to the audience. Professor Wang also presented water drainage technologies to prevent water logging after heavy rainfalls.
Case studies from German experts Patrick Paziener and Alejandro Figueroa completed the symposium. To prevent soil erosion, Patrick Paziener highlighted practices such as keeping the soil covered with straw. With average temperatures around -30° Celsius in winter, maintaining the ground covered is a major challenge that further exacerbates soil erosion. Using landscape elements such as hedgerows and reinforced field strips as well as adjusting the tire pressure of agricultural machinery to minimize soil compaction were mentioned as further practical solutions. Alejandro Figueroa presented the benefits of doing a proper soil analysis and experimenting with wider crop rotations. Both experts emphasized the use of conservation tillage techniques that loosen rather than turn the soil.
Field visits complement the event
Next to the symposium, the two and a half-day event involved a visit to the field site of the Heilongjiang Academy of Agricultural Sciences (HAAS), where researchers develop new crop varieties adjusted to short growing cycles in the region, experiment with the use of cover crops, and test different fertilizer applications to maintain long-term soil fertility. The experts also met with representatives of Heilongjiang’s renowned state farm Beidahuang and learned more about technological solutions offered by German agri-machinery companies at the 2024 Horsch field day (>> watch video).
Findings and recommendations
The following key points characterize the current situation concerning black soil protection and management in Heilongjiang Province:
With an annual grain output of around 80 million tons, Heilongjiang Province has been China’s number one grain growing province for 14 years.
Soil erosion, loss of organic matter, and compaction are leading to severe soil degradation. Over 60% of black soil farmland in the region is affected.
Extremely low temperatures in winter and short growing seasons make it difficult to keep the soil covered in winter and prevent erosion.
Spatial separation of crop and livestock farming disrupts nutrient cycles.
China is the first country to protect black soil through legislation. In 2022, China’s Black Soil Protection Law came into force, but its impact still needs to be evaluated.
The event helped identify several technical as well as practical approaches to halt soil degradation:
New tillage methods that minimize intrusive soil management: Unlike deep cultivation, which physically fractures the soil, conservation tillage ensures that the soil is left undisturbed and root systems are maintained, fostering a better soil structure.
Soil cover in winter: Leaving straw on the ground prevents soil erosion from wind and helps retain moisture.
Better nutrient management: Improved fertilization strategies, crop rotations, and intercropping promote nutrient recycling and enhance soil carbon.
Heterogeneous landscape elements: Integrating trees, hedgerows, and reinforced field strips into agricultural fields prevents soil erosion.
Structural changes: Re-integrating crop and animal production closes carbon and nitrogen cycles.