More attention should be paid to the health of deep soil in low-yield farmland!

With the global population expected to reach 9.6 billion by 2050, food demand is growing rapidly, posing challenges to achieving the Sustainable Development Goals. China, a large agricultural country that feeds 20% of the world’s population with 9% of the world’s farmland, needs to use agricultural resources more efficiently. However, nearly 70% of China’s arable land has low yields and serious problems such as soil acidification, groundwater pollution, and greenhouse gas emissions. Therefore, improving or maintaining good soil quality is of great significance for improving crop productivity. Many studies of food crops have focused on top soil (0–20 cm) and have not examined the relationship between deep soil health and crop productivity. However, deep soils are also key to crop growth and have different physical and chemical characteristics and microbial community structure than topsoil. Therefore, it is of urgent importance to study soil health from the two aspects of topsoil and subsoil. At the same time, soil microbes are key to maintaining soil health and function, and an in-depth understanding of microbial interactions and key microorganisms could promote soil health and plant growth by regulating these key plant-related microbial groups (such as AMF, actinomyces, and pseudomonas) in the future.

Based on the North China Plain, a typical winter wheat-summer maize rotation system was selected by postdoctor Sun Xinzhan from Zhang Junling's research group and associate professor Zhang Jiangzhou from Inner Mongolia Agricultural University. The soil health index and microbial network of 0–15 and 15–30 cm wheat fields with different yields were introduced, and the health status of the top soil and deep soil were evaluated. The relationship between microbials and soil health was revealed, and suggestions were put forward to enhance soil health and improve wheat yield. Better measures were taken to manage farmland soil and achieve green and sustainable development of agriculture while increasing production.

The results indicate that improving the surface soil health index has the potential to increase wheat yield in agricultural production, while the relationship between the deep soil health index and wheat yield is weak, but the higher soil health index in low-yielding fields may be an important factor to maintain wheat yield. Compared with low-yield wheat fields, high-yield wheat fields have more complex soil microbial networks, and actinomycetes, archaea and ascomycetes are important groups to improve soil health. A rich microbiome is therefore essential for soil health and crop yield. It is suggested that while strengthening the management of deep soil, agricultural measures such as bio-organic fertilizer, cover crops, no-till, residual retention, and crop rotation should be adopted to improve soil microbial networks to promote soil health and productivity.

This study has been published in the Journal of Frontiers of Agricultural Science and Engineering in 2024, 11(2) DOI: 10.15302/J-FASE-2024570.