Zhou Zhenxing, Tian Furong, Zhao Xiang, Zhang Kunpeng, Han Shijie
School of Biological and Food Engineering, Anyang Institute of Technology, Anyang, China.
Taihang Mountain Forest Pests Observation and Research Station of Henan Province, Linzhou, China.
Front Plant Sci. 2022 Oct 10;13:975169. doi: 10.3389/fpls.2022.975169. eCollection 2022.
Perennial cropping has been an alternative land use type due to its widely accepted role in increasing soil carbon sequestration. However, how soil organic carbon (SOC) changes and its underlying mechanisms under different cropping years are still elusive. A chronosequence (0-, 3-, 6-, 20-year) of perennial mugwort cropping was chosen to explore the SOC dynamics and the underlying mechanisms in agricultural soils of Northern China Plain. The results revealed that SOC first increased and then decreased along the 20-year chronosequence. The similar patterns were also found in soil properties (including soil ammonium nitrogen, total nitrogen and phosphorus) and two C-degrading hydrolytic enzyme activities (i.e., α-glucosidase and β-glucosidase). The path analysis demonstrated that soil ammonium nitrogen, total nitrogen, and plant biomass affected SOC primarily through the indirect impacts on soil pH, total phosphorus availability, and C-degrading hydrolytic enzyme activities. In addition, the contributions of soil properties are greater than those of biotic factors (plant biomass) to changes in SOC across the four mugwort cropping years. Nevertheless, the biotic factors may play more important roles in regulating SOC than abiotic factors in the long run. Moreover, SOC reached its maximum and was equaled to that under the conventional rotation when cropping mugwort for 7.44 and 14.88 years, respectively, which has critical implications for sustainable C sequestration of agricultural soils in Northern China Plain. Our observations suggest that short-term but not long-term perennial mugwort cropping is an alternative practice benefiting soil C sequestration and achieving the Carbon Neutrality goal in China.
多年生作物种植因其在增加土壤碳固存方面被广泛认可的作用，已成为一种替代性土地利用类型。然而，不同种植年份下土壤有机碳（SOC）如何变化及其潜在机制仍不清楚。选择了一个多年生艾草种植的时间序列（0年、3年、6年、20年）来探究华北平原农业土壤中SOC的动态变化及其潜在机制。结果表明，沿着20年的时间序列，SOC先增加后减少。在土壤性质（包括土壤铵态氮、总氮和磷）以及两种碳降解水解酶活性（即α-葡萄糖苷酶和β-葡萄糖苷酶）中也发现了类似的模式。路径分析表明，土壤铵态氮、总氮和植物生物量主要通过对土壤pH值、有效总磷和碳降解水解酶活性的间接影响来影响SOC。此外，在四个艾草种植年份中，土壤性质对SOC变化的贡献大于生物因素（植物生物量）。然而，从长远来看，生物因素在调节SOC方面可能比非生物因素发挥更重要的作用。此外，当种植艾草7.44年和14.88年时，SOC分别达到最大值且与传统轮作下的SOC相等，这对华北平原农业土壤的可持续碳固存具有关键意义。我们的观察结果表明，短期而非长期的多年生艾草种植是一种有利于土壤碳固存并实现中国碳中和目标的替代做法。
