Developing strategies to recover crop productivity after soil compaction-A plant eco-physiological perspective

Soil compaction constitutes a major threat to the fertility of arable soils and food security. The aim of this paper is to highlight the need and opportunities for plant eco-physiological approaches to identify strategies to recover crop yields after soil compaction. Reduced productivity on compacted soil primarily results from decreased root elongation rates and thus limited accessibility to water and nutrients. Hence, strategies to recover productivity after compaction must address plant eco-physiological phenomena that underlie low root system expansion rates. In compacted soil, root growth is decreased due to high soil penetration resistance and due to low oxygen concentration in soil air caused by reduced fluid transport capability. Thus, plant roots are exposed to a multi-stress environment, which needs to be addressed directly when aiming to recover productivity after compaction in the long-term. Here, we discuss possibilities to increase root growth in order to enhance resource accessibility and recover crop productivity on compacted soil. Yield recovery can be achieved through breeding of novel cultivars and targeted soil management approaches. On the one hand, the tolerance of plants to the different soil physical stresses can be enhanced by selecting for specific root traits that facilitate root growth in compacted soil. Soil management approaches that improve specific physical properties of compacted soil on the other hand can facilitate root growth in compacted soil. Since plant roots are major drivers of soil structure dynamics, increasing root growth in compacted soil may not only mitigate crop productivity losses but also recover soil structure.