Abstract
In China, the average soil organic carbon (SOC) content of cultivated land is 30% less than the world average. Therefore, cultivation management-induced changes in SOC dynamics are necessary, especially in estuarine alluvial islands, where the SOC stocks are limited. We studied the effect of different combinations of tillage, fertilization and straw return on C distribution in different soil aggregates and on crop yield on an estuarine alluvial soil in eastern China. Compared to conventional tillage, conservation tillage (no-tillage coupled with straw return) increased water-stable large macroaggregates (>2 mm) by 35.18%, small macroaggregates (2–0.25 mm) by 33.52% and microaggregates by 25.10% in the topsoil (0–20 cm). The subsoil (20–40 cm) also showed the same trend. Compared to conventional tillage without straw return, large and, small macroaggregates and microaggregates in conservation tillage were increased by 24.52%, 28.48% and 18.12%, respectively. Straw return also caused a significant increase in aggregate-associated carbon (aggregate-associated C). No-tillage coupled with straw return had more total aggregate-associated C within all the aggregate fractions in the topsoil. But the different is that conventional tillage with straw return resulted in more aggregate-associated C than conservation tillage in the subsoil. No-tillage combined with straw return (T8) produced the highest carbon preservation capacity (CPC) of macroaggregates and microaggregates in the topsoil. A considerable proportion of the SOC was found to be stocked in the small macroaggregates under both topsoil (74.56%) and subsoil (67.09%). The CPC was highest (19.17 g·kg−1) in small macroaggregates. However, no-tillage and straw return had less potential to sustain crop yield than did the conventional tillage practices; with the average rice and wheat yield correspondingly decreased by 10.63% and 7.82% in three years.
Highlights
Soil organic carbon (SOC) is an important soil component that plays a crucial role in soil fertility[1], environmental protection[2] and sustainable agricultural development[3]
The results of this study indicate that no-tillage and straw return are beneficial to the formation and stability of soil aggregates and promote the absorption of organic carbon, while no-tillage is more conducive to the fixation of soil organic carbon (SOC) in surface soil, and plowing in combination with straw return is more conducive to the accumulation of organic carbon in subsurface soil
Our results suggest that no-tillage and straw return in rice-wheat cropping rotation systems is an effective management practice for the formation and stability of soil aggregates, even in the estuarine alluvial soil of Chongming Island
Summary
Soil organic carbon (SOC) is an important soil component that plays a crucial role in soil fertility[1], environmental protection[2] and sustainable agricultural development[3]. 20–40 cm 5.47 ± 0.07bc 6.81 ± 0.04a 5.63 ± 0.17bc 6.30 ± 0.26ab 4.84 ± 0.05c 6.27 ± 0.05ab 4.82 ± 0.15c 5.39 ± 0.16bc 5.11 ± 0.24bc no-tillage, application of organic fertilizer, and straw return) increase the agriculture SOC stock[14,15,16,17], and improve crop yield[18,19] These measures mainly increase farmland SOC content by increasing SOC input and improving soil aggregate retention[20,21,22]. We hypothesized that no-tillage with straw return and chemical fertilizers could improve soil aggregation, C sequestration and sustainable yield increment in rice-wheat cropping rotation systems
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
