Former waste dump transformed into fields of corn

On the western outskirts of Hefei, Anhui province, a vast expanse of crops breaks through the soil on a plot that, just three years ago, lay buried under more than 10 million cubic meters of construction debris.

The site, once the No 3 Spoil Dump for the Yangtze-to-Huaihe River Diversion Project — the province's mega water infrastructure initiative designed to supply water to millions — was long considered a permanent ecological scar. Today, it has been engineered into 960 hectares of high-standard farmland, yielding successful harvests of rice, corn and rapeseed.

The transformation highlights how, under China's current 15th Five-Year Plan (2026–30), Anhui province is pioneering market-oriented reclamation models. Rather than treating infrastructure waste and food security as separate issues, local governments are partnering with private agribusinesses to ensure infrastructure projects leave behind usable land.

To address the damage left by years of dumping, engineers employed a layered reclamation approach. They first stripped and stockpiled whatever topsoil remained salvageable, then cut down the irregular mounds and regraded the debris in successive lifts. This process eliminated voids, prevented uneven settlement and restored drainage gradients across the site — prerequisites for any land intended to bear heavy agricultural machinery.

Sterile red sandstone spoil, which is unsuitable for crop growth, was buried deeper than one meter to isolate it from root zones. The preserved topsoil was then backfilled to the surface to rebuild the plow layer, where root systems develop and nutrients concentrate.

On the flattened terrain, agricultural infrastructure was upgraded. Fragmented plots were merged into contiguous fields to enable large-scale mechanized cultivation. Irrigation channels were dredged and lined to prevent seepage, while farm roads were rebuilt to support efficient drainage during heavy rains and machinery access.

The harder challenge, however, was soil recovery, as previous dumping had broken down soil aggregates and depleted organic matter.

To tackle this, researchers from the Institute of Soil Science of the Chinese Academy of Sciences in Nanjing analyzed local soil conditions and introduced green manure rotations, which involve planting cover crops and plowing them back into the earth while still green, allowing the nitrogen-rich biomass to decompose and rebuild soil fertility naturally. The team also applied organic compost at roughly 30 metric tons per hectare to gradually bring fertility up to high-standard farmland specifications.

Unlike conventional reclamation — which often means simply leveling debris and covering it with imported soil — the site adopted an integrated construction and operation model, with project teams responsible not only for reshaping the land but also for ensuring it could produce crops reliably.

In September 2023, the Ministry of Natural Resources launched a four-year pilot program on low-efficiency land redevelopment in 43 cities, districts and counties, targeting inefficient land use and irrational spatial layouts resulting from rapid urbanization. Hefei was among the designated pilot cities, bringing slag-dump reclamation under a more rigorous framework.

The reclaimed site is now operated by a leading agribusiness under a land-leasing model. Every April, golden blossoms across the restored terraces briefly turn the former dump into a suburban attraction, drawing photographers and weekend visitors.

The Anhui government said it has prioritized clearing the backlog of unremediated spoil sites and abandoned mines, integrating ecological restoration with food security goals rather than treating them as separate challenges.