Bio-tillage: A new perspective for sustainable agriculture

•Bio-tillage defined as improving soil structure by plant roots was proposed.•Cover crops with thick and deep roots can be used as bio-tillage tools.•Bio-tillage can benefit soil physical properties and crop growth by forming biopores.•Favorable management of bio-tillage is required for optimizing its benefits.•Bio-tillage can be combined with no tillage to promote sustainable agriculture. For sustainable agricultural production, we propose bio-tillage, which is defined as improving soil structure with plant roots to boost the growth of crops, in this paper. Cover crops with thick and deep roots can be used for bio-tillage since they can effectively improve soil structure and water and air conductivity by forming biopores (root channels), which provide space with the least resistance and a high level of oxygen and nutrients to promote root growth. The effect of bio-tillage on crop yields varies with climate conditions and management practices. An effective bio-tillage cover crop should have thick and deep roots with rapid root growth rates, rapid decomposition of remnant roots, and good adaption to climate and soil constraints. Planting cover crops in a timely manner and eliminating them at a suitable stage with a roller-crimper can benefit bio-tillage. The limited understanding of ideal biopore architecture for root growth, more effective bio-tillage cover crop species, and field management of bio-tillage, needs to be addressed before a wide application of bio-tillage.