Research on soil bacterial community assembly and function under different straw returning practices in arid and semi-arid agricultural ecosystems over multiple years

Summary

This multi-year field study examined how continuous straw return practices affect soil bacterial community assembly and function in the semi-arid Tumu Chuan Plain Irrigation Area. Using 16S rRNA sequencing and metabolic pathway predictions, the authors found that deep ploughing with straw incorporation (DPR) and no-tillage mulching (NTR) significantly enhanced microbial diversity and ecosystem stability compared to conventional shallow rotation, primarily through changes in soil organic matter and enzyme activity driving shifts toward more stable, cooperative bacterial networks.

UK applicability

Findings may have limited direct applicability to UK arable systems given the semi-arid climate context and irrigation practices of the study region, though the underlying mechanisms of how straw management alters bacterial community assembly and metabolic capacity could inform UK soil health strategies. The relative benefits of conservation tillage and organic matter retention identified here align with UK soil health priorities, though local validation would be needed to optimise straw management practices under temperate, higher-rainfall conditions.

Key measures

16S rRNA gene sequencing; relative abundance of bacterial phyla; K-strategist to r-strategist ratio; carbohydrate and amino acid metabolism predictions (via PICRUSt2); bacterial network stability; homogenous selection and drift effects; bacterial aggregation levels; soil organic matter; enzyme activity

Outcomes reported

The study measured shifts in soil bacterial community structure, relative abundance of bacterial phyla, life history strategies (K- and r-strategists), metabolic pathways, and assembly mechanisms across four straw management treatments. Results showed that deep ploughing with straw return (DPR) and no-tillage mulching (NTR) significantly altered bacterial diversity, enhanced carbohydrate and amino acid metabolism, and promoted more stable bacterial networks compared to conventional shallow rotation practices.

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