China's land geochemical conditions have shown steady improvement in overall soil productivity and ecological functions over the past 30 years, according to a recent report published by the China Geological Survey under the Ministry of Natural Resources.

The report, titled National Land Geochemical Monitoring Report 2025, analyzed more than 500,000 national-scale land geochemical monitoring data records from 1995, 2016 and 2023.

"National land geochemical comprehensive analysis reveals that, in 2023, 92.6 percent of land areas were rated as medium grade or above — an increase of 0.4 percentage points compared to 1995," said Peng Min, a researcher at the China Geological Survey who led the survey. He added that the analysis was based on chemical element contents related to soil nutrients and ecological conditions.

Peng noted that the country's consistent implementation of major ecological protection and restoration projects — such as the Three-North Shelterbelt Forest Program, the conversion of farmland back to forests, and the promotion of water-saving technologies — may all have had a positive influence on the improvement.

During the 28-year monitoring period, levels of key elements in soil minerals — such as silicon, aluminum, iron, calcium, sodium and magnesium — remained relatively stable. Peng compared these elements to the "skeleton" of the soil, noting that their excessive accumulation or depletion is associated with land degradation issues such as acidification, salinization and desertification. The stability of these elements reflects that the soil's physical structure remains largely intact.

Levels of essential macronutrients for plant growth — such as nitrogen, phosphorus and potassium — as well as vital micronutrients for plants and the human body, including manganese, selenium and iodine, have slightly increased. These elements are crucial for crop yield and nutritional quality, and a moderate rise in their content suggests a positive influence on food security and human health, Peng said.

The report also indicates an overall increase in organic carbon content, with the amount of organic carbon in one kilogram of soil rising from 6.7 grams to 7.8 grams between 1995 and 2023.

"Organic carbon can enhance the soil's ability to retain water and nutrients. It creates numerous pores in the soil that absorb and hold moisture, while its electrical charges attract and retain nutrient ions from fertilizers, preventing them from being easily washed away by rainfall and boosting plant growth," Peng said, highlighting how higher organic carbon content creates a virtuous cycle through carbon sequestration via plant photosynthesis.

Regionally, organic carbon content on the Qinghai-Xizang Plateau increased by 141.4 percent during the monitoring period, according to the report.

Cheng Hangxin, a researcher at the China Geological Survey, said this suggests the ecological environment of the plateau is further improving, influenced by a warming and wetting climate, as well as protective measures such as modified grazing practices. Moreover, as a major global carbon sink, the plateau absorbs significant amounts of carbon dioxide from the atmosphere, playing an increasingly important role in mitigating the global greenhouse effect.

"During the 15th Five-Year Plan period (2026-30), the China Geological Survey will establish higher-resolution monitoring in key agricultural areas, with an additional 6,000 new monitoring sites planned for this year," Peng said. "We will continue the monitoring project, aiming to conduct a national-scale survey every 10 years and a regional-scale survey every five years."