Long-term subsoiling and no-tillage with moderate nitrogen regulate soil carbon sequestration, microbial cbbL expression, and maize yield under semi-arid plastic mulching

[Geoengineering News]

https://link.springer.com/article/10.1007/s11104-025-08235-3

Authors: Umar Daraz, Junhong Xie, Lingling Li, Yongjie Zhou, Muhammad Farhan Saeed & Aftab Jamal 

20 January 2026

Abstract

Aims

Appropriate tillage and nitrogen management are crucial for promoting carbon sequestration, improving yields, and sustaining rain-fed agriculture. However, the long-term effects of tillage and nitrogen rates on soil carbon sequestration under plastic film–mulched (PFM) dryland maize and their microbial and physicochemical mechanisms remain unclear.

Methods

A long-term field experiment (2012–2020) was conducted on Calcaric Cambisol soils of the Chinese Loess Plateau using two factors: tillage methods (T1, conventional (20 cm); T2, rotary (15 cm); T3, no-tillage; and T4, subsoil tillage (35 cm) and nitrogen fertilization rates (200 and 300 kg N ha−1; N2 and N3).

Results

Tillage and its interaction with nitrogen significantly affected maize yield, biomass, soil aggregates, organic carbon fractions, cbbL gene expression, and carbon-sequestering microbial communities. Subsoil tillage with 200 kg N ha⁻1 (T4N2) increased the yield and biomass. Compared with rotary tillage, no-tillage and subsoil tillage with 200 kg N ha⁻1 (T3N2, T4N2) enhanced soil organic carbon (SOC), particulate organic carbon (POC), water content, pH, available phosphorus (AP), aggregation, and C:N ratio. T4N2 and T3N2 also showed higher cbbL expression, microbial diversity, and carbon-fixing taxa (Proteobacteria, Sphingomonas, Nitrosospira, Synechococcus, and Acidithiobacillus), promoting carbon sequestration and yield. Structural equation modelling revealed that tillage and nitrogen indirectly enhanced carbon sequestration and yield by altering the microbial composition.

Conclusions

No-tillage or subsoil tillage with 200 kg N ha⁻1 under PFM significantly improved carbon sequestration and maize productivity in semi-arid regions.

Source: Springer Nature Link