Bio‐tillage improves soil physical properties and maize growth in a compacted Vertisol by cover crops

Abstract

Bio‐tillage has recently been proposed as a measure to alleviate soil compaction through biopores created by cover crop roots. The objective of this study was to determine the effect of different cover crops on soil physical properties and the succeeding maize (Zea mays L.) growth in compacted soil. Four treatments, including no cover crop as a control (Con), alfalfa (Medicago sativa L.), oilseed rape (Brassica napus L.), and radish and hairy vetch mixture (Raphanus sativus L. and Vicia villosa Roth), were carried out under both compacted and noncompacted soil conditions. Soil physical properties, such as the volumetric soil water content (SWC), bulk density, saturated hydraulic conductivity (Ks) and air permeability at water potential of −60 hPa (Ka60), and maize root characteristics and yield were measured. The cover crops did not affect the soil bulk density but significantly decreased the SWC in both the compacted and noncompacted soils relative to the Con treatment. The alfalfa treatment presented significantly higher Ks in the noncompacted soil and Ka60 in both the compacted and noncompacted soils than the Con treatment in the soil layer depth of 20–50 cm. The three cover crop treatments improved the maize root biomass density (173.2% for 2018 and 35.6% for 2019) and root length density (50.9% for 2018 and 51.8% for 2019) relative to the Con treatment in the soil layer depth of 10–70 cm in 2018 and soil layer depth of 10–50 cm in 2019 in the compacted soil rather than in the noncompacted soil. Compared with the Con treatment, the radish mixed with hairy vetch treatment in 2018 and the oilseed rape treatment in 2019 significantly enhanced the maize yield in the compacted soil. Our results suggest that alfalfa is the best crop for improving air permeability; however, the oilseed rape and mixture of radish and hairy vetch lead to better maize growth in the compacted soil. Bio‐tillage using cover crops is effective in alleviating soil compaction.

Biological conservation measures are better than engineering conservation measures in improving soil quality of eroded orchards in southern China

“…Soil samples were collected from the 0‐to‐100 cm depth (0–10, 10–20, 20–40, 40–60, 60–80, and 80–100 cm) using a 5‐cm soil auger. Previous studies have shown that the effects of different management practices on soil properties and functions can reach deeper soil layers (Bordoni et al., 2019; Z. Zhang et al., 2022). Soil quality evaluation based on both surface and subsurface properties can help to identify the maximum influence of different measures on soil properties and functions.…”

How does building healthy soils impact sustainable use of water resources in irrigated agriculture?

“…Biopores, such as those formed from roots or earthworms and preserved when soil is not disturbed, enable steeper-angled axial roots to penetrate deeper (Stirzaker et al, 2017;Xiong et al, 2022). Selection of cover crops or preceding cash crops that promote biopores helps subsequent cash crops develop deeper roots (Huang et al, 2020;Zhang et al, 2022). In turn, this would support reducing applied water, such as through partial root drying (Barrios-Masias and or with less frequent irrigations at drier soil moisture thresholds (Devine and O'Geen, 2019).…”

Root and root‐derived biopore interactions in soils: A review

“…Several studies found that in well-structured soils, the biopores have little effect on the root system. Xiong, Zhang, Wang, et al (2022) observed that maize roots did not tend to colonize the biopores in loose soil. Under good aeration conditions, Dexter (1986) found no evidence of preferential root growth toward the biopores.…”

“…Pulido-Moncada et al (2022) found that cover crops such as lucerne could create many vertical and wellconnected biopores in compacted subsoil. Zhang et al (2022) reported that bio-tillage using cover crops improved air permeability and root growth and increased yield of succeeding maize in compacted soil. This indicates that biopores formed by bio-tillage play a significant role in promoting plant growth in compacted soil.…”

“…Zhang et al. (2022) reported that bio‐tillage using cover crops improved air permeability and root growth and increased yield of succeeding maize in compacted soil. This indicates that biopores formed by bio‐tillage play a significant role in promoting plant growth in compacted soil.…”