agriculture data
Description
Intensive winter wheat-summer maize rotation in the North China Plain (NCP) degrades soil quality by suppressing soil organic carbon (SOC) sequestration. Although as a more sustainable way, the grass-crop rotation system has an unclear impact on the soil carbon (C) sequestration effect, especially on the SOC and microbial necromass carbon (MNC) components. A triticale (×Triticosecale Wittmack)-hairy vetch (Vicia villosa Roth.) mixed sowing followed by maize (Zea mays L.) rotation was established under two irrigation rates (W1: 750 m3·hm⁻2; W2:375 m3·hm-2) and two nitrogen (N) application rates (N1: 188 kg·hm-2; N2: 94 kg·hm-2). A monoculture triticale-maize rotation was the control (CK). Compared with CK, grass-crop rotation increased preceding crop yield by 1344.29 kg in 2023 and 2774.50 kg in 2024, and subsequent crop yield by 4876.06kg in 2023. In 2024, SOC under grass-crop treatments increased by 6.75% (0-15 cm) and 5.00% (15-30 cm). The grass-crop rotation system increased the soil total carbon concentration but decreased the NO3--N and NH4+-N concentrations. Furthermore, it did not affect the stability of soil aggregates. However, under the same water-fertilizer management treatments, the MNC concentration within all soil aggregate size fractions was reduced. Structural equation modeling revealed that the rotation system and water-fertilizer management directly affected the yield, while more important was that the grass-crop rotation system also influenced SOC sequestration through an indirect pathway by maintaining soil aggregate stability. These findings elucidate the mechanisms by which grass-crop rotations enhance SOC conservation, achieving both ecological and economic benefits.
Files
Institutions
- China Agricultural UniversityBeijing, Beijing