长期施肥对褐土有机碳矿化的影响

Effects of Long-term Fertilization on Organic Carbon Mineralization of Cinnamon Soil

以26a长期定位施肥试验为依托,选取其中6个具有代表性的施肥处理:N3P3(单施化肥)、N3P4M1(施用化肥及低量有机肥)、N3P1M2(施用化肥及低量有机肥)、N3P2M3(施用化肥及低量有机肥)、M6(单施有机肥),以不施肥为对照(CK),采用室内模拟培养试验法研究了长期施肥对褐土有机碳矿化的影响,为科学管理褐土土壤肥力提供依据。结果表明,不同施肥处理使土壤有机碳含量提升了6.28%~156.75%,以M6处理土壤有机碳含量最高。不同处理土壤有机碳矿化速率均在培养第2天达到峰值,随后急剧下降,第4天后各处理的土壤有机碳矿化速率变化趋于一致,且培养期间各处理土壤有机碳矿化速率随培养时间的变化符合对数函数关系。培养32d后,各处理土壤有机碳累积矿化量介于1021.12~2066.86mg/kg,以M6处理最高,较CK提高了102.41%。长期施肥处理均降低了土壤有机碳累积矿化率,以M6处理下降最明显,与CK相比,降低了2.35%。一级动力学方程的拟合结果表明,长期施肥处理均提高了土壤潜在可矿化有机碳量,以M6提高最为显著。此外,长期施肥处理均提升了土壤有机碳库的周转速率,缩短了土壤有机碳库半周转期。综上,M6、N3P4M1、N3P1M2、N3P2M3处理在提高土壤有机碳累积矿化量的同时降低了其土壤有机碳累积矿化率,加强了土壤的固碳能力。单施有机肥可作为褐土培肥管理的最佳选择。

Based on the 26 years long-term fertilization experiment,chose 6 representative fertilization treatments:N 3P 3(single application of chemical fertilizer),N 3P 4M 1(application of chemical fertilizer and low-level organic fertilizer),N 3P 1M 2(application of chemical fertilizer and low-level organic fertilizer),N 3P 2M 3(application of chemical fertilizer and low-level organic fertilizer),M 6(single application of organic fertilizer),no fertilization as control (CK),used the indoor simulated culture test,to study the effects of long-term fertilization on the organic carbon mineralization of cinnamon soil, and to provid a basis for scientific management of cinnamon soil fertility.The results showed that,the soil organic carbon content increased by 6.28% to 156.75% of different fertilization treatments,and the soil organic carbon content of M 6 treatment was the highest.The soil organic carbon mineralization rate of different fertilization treatments peaked on the 2nd incubation day,then decreased sharply,the soil organic carbon mineralization rate of each treatment tended to be consistent after the 4th day,and the carbon mineralization rate and change of incubation time was logarithm function.After 32 days of incubation, the cumulative mineralization of soil organic carbon of each treatment ranged from 1 021.12 to 2 066.86 mg/kg, which was the highest with M 6 treatment, and increased by 102.41%compared with CK.Long-term fertilization treatments reduced the cumulative mineralization rate of soil organic carbon,which was the most obvious with M 6 treatment,and decreased by 2.35% compared with CK.The fitting results of the first-order kinetic equation showed that,long-term fertilization treatments increased the soil potential mineralizable organic carbon,and M 6 treatment was the most significant.In addition,long-term fertilization treatments increased the turnover rate of soil organic carbon pool and shortened the half-turn period of it.In summary,M 6,N 3P 4M 1,N 3P 1M 2 and N 3P 2M 3 promoted the cumulative mineralization of soil organic carbon while reducing the cumulative mineralization rate of soil organic carbon and strengthened the soil carbon sequestration capacity.Singal application of organic fertilizer could be took as the optimal choice of cinnamon soil fertility management.