摘要
【目的】研究不同施肥管理措施下农田土壤有机碳的变化规律,探明灰漠土有机碳含量提升及定向培育指标。【方法】依托始于1990年的国家灰漠土肥力与肥料效益长期定位监测试验,分析耕层与剖面土壤有机碳(SOC)的动态演变特征,拟合有机碳SOC(g/kg)与试验持续时间t(a)的线型回归方程,确定土壤有机碳变化的特征值。【结果】耕层(0~20 cm)土壤有机碳含量与施肥年限间存在显著相关性,配施有机肥(1.5NPKM、NPKM)和PK处理达极显著相关;施用有机肥(1.5NPKM、NPKM)土壤有机碳的增加速率分别是秸秆还田(NPKS)的28.8和15.2倍。除NP处理表现为增碳外,其他施用化肥处理均表现为减碳。NK、NPK、N、PK处理土壤有机碳下降速率依次为0.024、0.027、0.031和0.059 g/(kg·a)。灰漠土有机碳投入的平均转化效率为23.6%(线性方程:Ssoc=0.236C-0.306(R2=0.894,P<0.001)),维持新疆灰漠土有机碳的碳投入量为1.3 t/(hm^2·a)。【结论】与不施肥或长期施用化肥相比,在干旱区灰漠土采用有机无机配施固碳效应显著,其碳投入与土壤有机碳呈显著线性正相关(P<0.001),增加土壤碳投入(有机肥或秸秆)仍然是提升或维持土壤肥力的主要措施。
[ Objective ] To study the effect of long - term different fertilization regimes on soil organic car- bon （SOC） and the sequestration rate of SOC. [ Method ] A long - term experiment was conducted using vari- ous fertilizations from 1990 to 2014 in wheat （Triticum aestivium） and maize （Zea mays） crop rotation system in grey desert soil. Using undisturbed soil samples from the surface and subsurface layers, we explored the se- questration rate of SOC. Regression analyses were used to test the relationships between the contents of SOC and the time series. [ Result] Results showed that the C concentrations in the surface layers （0 -20 cm） were significantly correlated with the time series by fertilization under 1.5NPKM, NPKM, and PK treatments. Com- pared to NPKS treatment, the C sequestration rates under manure added treatment （1.5NPKM and NPKM） were 28.8 and 15.2 times, respectively. The annual C decreasing rates under NK, NPK, N and PK treat- ments were 0. 024 g/（ kg · a）, 0. 027 g/（kg · a）, 0. 031 g/（ kg · a） and 0. 059 g/（ kg · a）, respectively a- side from NP treatment. In addition, the C sequestration rate was 23.6 % from the exogenous C input （ linear equations： Ssoc = 0. 236 C-0. 306, R^2= 0.894,P 〈 0. 001 ）, and the carbon input was 1.3 t/（hm^2 · a） in order to sustain the level of SOC in grey desert soils. [ Conclusion ] Compared to CK and mineral fertilizer added treatments, increasing carbon input （manure or straw returned） was significantly positively correlated with SOC sequestration （P 〈 0. 001 ）. Thus, increasing exogenous C input （manure or straw returned） plays a key role in C sequestration and improving soil fertility in the grey desert soil area.
作者
王西和
蒋劢博
王志豪
刘骅
WANG Xi - he JIANG Mai - bo WANG Zhi - hao LIU Hua(Research Institute of Soil, Fertilizer and Agricultural Water Conservation / key Laboratory of Oasis Nutrient And Efficient Utilization of Water and Soil Resources, Xinjiang Academy of Agricultural Sciences /National Gray Desert Soil Fertility and Fertilizer Effect Monitoring Station, Urumqi 830091, China)
出处
《新疆农业科学》
CAS
CSCD
北大核心
2016年第12期2299-2306,共8页
Xinjiang Agricultural Sciences
基金
新疆维吾尔自治区自然科学基金项目"长期施肥下新疆灰漠土有机碳库演变特征与固碳潜力"(2012211B43)~~
关键词
长期定位施肥
土壤有机碳
演变特征
有机碳储量
固碳速率
long- term fertilization
soil organic carbon
evolution characteristics
soil organic carbon storage
C sequestration rate
