Different tillage and stubble management practices affect root growth and wheat production in a semi-arid area

Aims The spring wheat root traits was rarely studied under conservation tillage in semi-arid regions. We investigated the effects of different tillage and stubble management practices on spring wheat root growth, grain yield, and water use efficiency (WUE). Methods A field trial on different tillage and stubble management practices was established in 2001, including four treatments: Traditional tillage without stubble retention (T); No-tillage and no stubble retention (NT); Tillage with stubble incorporation (TS); and No-tillage with stubble retention (NTS). Soil and plant samples in this paper were collected in 2020 (wet year) and 2021 (dry year). Soil moisture content was measured in the 0–200 cm soil depth by layer. Roots were collected by excavating soil columns, washed and then scanned. Results NTS increased soil water content by 13.7–62.1% compared with T in the 0–50 cm soil layer in 2020 and 2021. The root system in the wet year (2020) was much better than the dry year (2021). Average root diameter, total root surface area, and total root length maintained a higher level over the whole growth stage under NTS compared with other treatments. NTS was beneficial for improving root dry matter, in addition, it showed a significant increase in root vigor of 38.5–67.3% compared to T in both dry and wet years. The grain yield of different treatments in 2020 was much higher than in 2021; the average grain yield of NTS was 13.2% and 21.1% higher than T in 2020 and 2021, respectively. Furthermore, the WUE of NTS was significantly higher than other treatments in the two years, and it was much better in the dry year (2021). Conclusions In different years, spring wheat yield and water use efficiency varies with soil water content and root system. No-tillage with stubble retention promote spring wheat yield and water use efficiency by increasing soil water content, improving root growth and enhancing root vigor. No-tillage with stubble retention was better in drier year.