有机无机肥长期配施对果园土壤碳库及温室气体排放的影响

有机肥的施用可以提高土壤总有机碳和活性有机碳含量，在改善土壤质量，提升土壤肥力方面有重要意义.设4个处理：不施肥（CK）、单施有机肥（M）、单施化肥（NPK）和有机无机肥配施（MNPK），研究长期有机无机配施下土壤有机碳和其活性组分含量变化，分析不同施肥措施对温室气体排放的影响，并评估了土壤碳库管理指数的变化.结果表明，与CK处理相比，MNPK处理的土壤总有机碳（TOC）、微生物量碳（MBC）、可溶性有机碳（DOC）、易氧化有机碳（EOC）和颗粒有机碳（POC）含量分别增加了82.84%、66.30%、21.12%、93.28%和145.80%.NPK处理对土壤总有机碳和有机碳组分含量无显著差异.有机无机配施有利于提高土壤碳库活度指数（LI）、土壤碳库指数（CPI）和土壤碳库管理指数（CPMI），LI和CPI的增加是CPMI增加的主要原因.相关分析表明土壤有机碳组分和CPMI与温室气体排放呈显著正相关关系；有机无机配施增加了CO₂累积排放量和增温潜势（GWP），但却能够降低温室气体排放强度（GHGI）；MNPK处理产量最高，为56365 kg ·hm^-2，较CK处理（29073 kg ·hm^-2）提高了93.87%.因此，旱地苹果园有机无机肥配施，可促进有机碳的累积，稳定土壤碳库，更有利于果园的可持续发展.

Effects of Long-term Combined Application of Organic and Inorganic Fertilizers on Soil Carbon Pool and Greenhouse Gas Emissions in Orchards

Applying organic fertilizer can increase the contents of soil organic carbon (SOC) and active organic carbon, which are crucial for strengthening soil quality and fertility. Four treatments were established:no fertilization (CK), single application of organic fertilizer (M), single application of chemical fertilizer (NPK), and combined application of organic and inorganic fertilizers (MNPK). The changes in SOC and active components under long-term combined application of organic and inorganic fertilizers were investigated, as were the effects of various fertilization measures on greenhouse gas emissions. Moreover, we evaluated the variation in the soil carbon pool management index (CPMI). Total organic carbon (TOC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), easily oxidized organic carbon (EOC), and particulate organic carbon (POC) increased by 82.84%, 66.30%, 21.12%, 93.28%, and 145.80%, respectively, when compared to those in the CK treatment. The NPK treatment had no discernible effect on SOC and organic carbon components. The combined application of organic and inorganic materials could enhance LI, CPI, and the soil carbon pool management index, with the increase in LI and CPI being the primary reason for the increase in CPMI. Correlation analyses revealed that soil organic carbon components and CPMI were significantly positively correlated with greenhouse gas emissions. The combined application of organic and inorganic materials enhanced cumulative CO₂ emissions and warming potential (GWP) but decreased GHGI and yielded a maximum of 56365 kg·hm^-2. Compared with that in the CK treatment (29073 kg·hm^-2), apple yield in MNPK increased by 93.87%. Therefore, applying organic and inorganic fertilizers in dryland apple orchards can improve the accumulation of organic carbon and stabilize the soil carbon pool, which is more beneficial to the sustainable development of orchards.