摘要： 为揭示小麦秸秆还田及施肥对潮土土壤有机碳演变的影响，以指导华北潮土培肥增产。在辛集马兰设置22 a潮土长期定位试验（1992-2014年，试验包含4个处理，NP：不施钾+秸秆不还田；NPK：平衡施肥+秸秆不还田；NPS：不施钾+小麦秸秆还田；NPKS：平衡施肥+小麦秸秆还田），研究不同施肥措施下试验年限、碳投入、碳平衡与土壤有机碳含量的响应关系。结果表明：所有处理表层（0~20 cm）土壤有机碳含量随时间均呈增加趋势，NP、NPK、NPS、NPKS增加速率分别为0.06，0.17，0.25，0.34 g/（kg.a），且22 a后各处理土壤有机碳储量均增加，分别增加为2.2，6.2，5.9，8.9 t/hm²，固碳速率分别为0.10，0.28，0.27，0.40 t/（hm² · a）。土壤有机碳储量变化与累积碳投入变化量呈线性相关关系（y=0.091x-0.241，R ²=0.360^*），在小麦秸秆还田下，维持初始有机碳水平的累积碳投入量为2.65 t/hm²，固碳效率为9.1%。通过边界线分析可知，小麦和玉米生产中稳产高产最低土壤有机碳含量分别为9.47，9.04 g/kg，未达到此值时土壤有机碳含量每增加1 g/kg，小麦籽粒产量增加167.5 kg/hm²，玉米籽粒产量增加678.5 kg/hm²。秸秆还田和平衡施肥是华北潮土有机碳含量提升和土壤碳库保育的重要手段，连续秸秆还田和平衡施肥对保证该区域粮食生产高产稳产有重要作用。

关键词: 华北潮土, 长期施肥, 有机碳, 固碳速率, 固碳效率

Abstract: Understanding the effects of wheat straw returning and fertilization on the evolution of soil organic carbon(SOC) in in fluvo-aquic soil can be beneficial to soil fertility and crop yield in North China Plain. A long-term fertilization experiment was established from 1992 to 2014 in Malan town, Xinji city, Hebei Province. There were four treatments in this experiment(NP: No potassium and no straw returning; NPK: Balanced fertilization and no straw returning; NPS: No potassium and wheat straw returning; NPKS: Balanced fertilization and wheat straw returning). We explored the relationship between SOC and fertilization years, carbon inputs and carbon balance. The results showed that SOMs in 0-20 cm layer increased with the fertilization year in all treatments. And the increasing rate were 0.06, 0.17, 0.25, 0.34 g/(kg · a) in NP,NPK,NPS,NPKS, respectively. After 22 years, the soil organic carbon storage in each treatment increased by 2.2, 6.2, 5.9, 8.9 t/ha, respectively, and the carbon sequestration rates were 0.10, 0.28, 0.27, 0.40 t/(ha · a).Moreover, there was a linear correlation between the change of soil organic carbon storage and the cumulative carbon input. When the wheat straw was returned to the field, the cumulative carbon input to maintain the initial organic carbon level was 2.65 t/ha, and the carbon sequestration efficiency(CSE) was 9.1%. The minimum SOC contents to support the stable and high yield of wheat and maize were 9.47,9.04 g/kg, respectively. If the SOC had not achieved the above level, the wheat and maize grain yield would increase 167.5,678.5 kg/ha with the SOC increasing per 1 g/kg, respectively. Straw returning and balanced fertilization were the effective means to promote the organic carbon content and conserve soil carbon pool in fluvo-aquic soil of North China Plain, which played a crucial role in ensuring food security in this region.

Key words: Fluvo-aquic soil of North China Plain, Long-term fertilizer, Organic carbon, Carbon sequestration rate, Carbon sequestration efficiency

中图分类号: 

• S143