Background Gully erosion greatly harms the ability of crop production and agroecosystem due to the loss of arable soil and the obstacle of tractor travel. Gully erosion is a big issue and urgently needed to renovate for the agricultural sustainable development in the Molliosls area of Northeast China.

Methods An innovative rehabilitation engineering of gully filling in the farmland was set up. The basic design principle was the gully disappearance with the gully body filled by straw and its surface covered by soil. A drainage system consisting of conceal conduit and seepage pit was established under ground. New gully will be not formed in the filled area, and tractors can move freely.

Results The rehabilitation engineering consists of gully reshaping, conceal conduit laying, straw bundling, straw bundle stacking, surface earthling, earth bund constructing, seepage pit building and exit protecting. The land destroyed by gully erosion was filled and gully disappeared. The stream on the surface of rehabilitation gully got into the conceal conduit through the infiltration of gully surface covered soil and the seepage pit to straw layer, then concentered to the conceal conduit. More than 90% of the converged flow was drained out the field from underground, which greatly decreased the power of water flow and no new gully was formed. Small gully or the brand of median and large gully with the depth ≤ 2 m could be rehabilitated by this engineering. Up to now, over 300 gullies was rehabilitated by the national projects of gully controlling, Mollisols land protecting and territorial controlling in the Mollisols area of Northeast China, and 1.33 km² farmland was rehabilitated. More than 0.2 million gullies and 1 333 km² farmland are expected to be rehabilitated by the engineering in the northeast of China. About 0.6 billon kg grains would be increased each year.

Conclusions The key technology of the gully rehabilitation engineering is to change the surface water flow to the conceal conduit and seepage pit drainage. The optimal gullies for the rehabilitation are formed in the farmland and their depths are < 2 m.