滇南地区桃树种植模式对土壤有机碳组分及碳库管理指数的影响

经果林种植可改变土壤质量、改善生态环境，同时具有较高的经济效益。合理的种植模式可通过物种间的互补性提高资源利用效率，改善土壤碳库质量并提高综合效益。为探讨桃树种植模式对土壤有机碳组分及碳库管理指数的影响，以云南省开远市不同桃树种植模式(桃树单种-SP和桃树南瓜套种-PP)为研究对象，以毗邻的天然林地(CK)为对照，分析不同种植模式下活性碳库，即高锰酸钾氧化有机碳(POXC)、颗粒有机碳(POC),惰性有机碳库即矿物结合态有机碳(MAOC)在0—40 cm土层的分布情况，明确土壤有机碳组分与土壤理化性质的关系；计算碳库活度指数(CPAI)、碳库指数(CPI)以及碳库管理指数(CPMI),明确不同桃树种植模式的碳库变化情况。结果表明：桃树种植模式和对照的土壤有机碳组分的含量均随着土层深度的增加而减少，平均土壤有机碳(SOC)含量为：14.68 g/kg(CK)>9.57 g/kg(PP)>8.58 g/kg(SP)。平均活性有机碳组分所占比例与POC/MAOC均表现为：SP>CK>PP,PP的活性有机碳比例较低，具有较高的有机碳稳定性。两种桃树种植模式的CPMI在1...

Effects of peach tree planting patterns on soil organic carbon fractions and carbon pool management index in southern Yunnan

The ecological environment in southern Yunnan is fragile with serious land degradation. Economic orchard, as a major ecological management, has a certain effect on organic carbon sequestration. Reasonable planting patterns can improve resource utilization efficiency through the complementarity between species, increasing the quality of soil carbon pool and obtaining higher comprehensive benefits. This study was carried out on different planting patterns of peach single species (SP) and peach pumpkin interplanting (PP), located in Taoyuan Village, Kaiyuan City, Yunnan Province. Taking the adjacent natural forest (CK) as control, soil organic carbon (SOC), permanganate oxidizable carbon (POXC), particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) were measured in 0-40 cm soil layer at an interval of 10 cm. Meanwhile, we calculated carbon pool activity index (CPAI), carbon pool index (CPI) and carbon pool management index (CPMI). Our objective was to investigate the effects of peach tree planting patterns on the stability of soil organic carbon and CPMI and clarify the relationship between soil organic carbon fractions and soil physicochemical properties. The results showed that the content of soil organic carbon fractions of the peach tree planting patterns and the control decreased with the increase of soil depths, the average SOC content were 14.68 g/kg (CK), 9.57 g/kg (PP), 8.58 g/kg (SP), respectively. The proportion of average POC, POXC and POC/MAOC showed as SP>CK>PP. PP had a lower proportion of active organic carbon with better organic carbon stability. Moreover, the CPMI of both peach tree planting patterns were lower than CK and reached the maximum value in the layer of 10-20 cm. SP had a higher CPAI (1.10), while PP had a higher CPMI (69.51), indicating that the stability and quality of PP soil carbon pool was better than that of SP. SOC, POXC, POC, and MAOC were all significantly positively correlated with sand, C/N, available phosphorus, exchangeable potassium, pH, and total phosphorus (in order of correlation). Peach tree planting patterns, soil depth and their interaction had different effects on soil organic carbon fractions and its proportion. Redundancy analysis also showed that sand and pH were the main environmental factors affecting the soil organic carbon fractions and soil organic carbon pool under different peach tree planting patterns and soil depths. We concluded that peach tree planting patterns changed the SOC and its fractions. Here, we consider PP as a better planting pattern, which is beneficial to organic carbon sequestration. Appropriate management measures should be taken according to the soil properties, basic situation of carbon pool and the effectiveness of nutrients such as nitrogen and phosphorus, so as to enhance the carbon sequestration efficiency and carbon sink level while improving the economic benefits.