化肥减量配施有机肥对土壤有机碳及其组分的影响

为了探究化肥减量配施两种不同黄腐酸钾有机肥对土壤有机碳及其组分的影响，采取盆栽模拟大田种植，以不施肥和纯施化肥为对照，以100%化肥配施100%有机肥、75%化肥配施25%有机肥、50%化肥配施50%有机肥、25%化肥配施75%有机肥和100%有机肥为处理，探讨土壤有机碳（SOC）、可溶性有机碳（DOC）、微生物量碳（MBC）、易氧化有机碳（LOM）和惰性有机碳（ROC）在不同生育期内的含量特征。结果表明：化肥减量配施有机肥各处理有机碳及其组分含量各生育期均表现为：花针期显著高于结荚期和成熟期，其中可溶性有机碳和微生物量碳结荚期含量显著高于成熟期（P＜0.05）；各处理有机碳及其组分含量均表现为：25%化肥配施75%生化黄腐酸钾处理显著高于不施肥、单施化肥和单施有机肥处理，50%化肥配施50%矿源黄腐酸钾处理显著高于不施肥、单施化肥和单施有机肥处理；其中花针期25%化肥配施75%生化黄腐酸钾处理SOC、DOC、MBC、LOM和ROC含量分别为133.0 g·kg-1、284.4 mg·kg-1、269.7 mg·kg-1、30.76 g·kg-1和111.2 g·kg-1，50%化肥配施50%矿源黄腐酸钾处理SOC、DOC、MBC、LOM和ROC含量分别为130.9 g·kg-1、250.5 mg·kg-1、251.7 mg·kg-1、29.86 g·kg-1和110.8 g·kg-1。综上，化肥减量配施生化黄腐酸钾对土壤有机碳及其组分含量的影响整体优于配施矿源黄腐酸钾（P＞0.05），各生育期有机碳及其组分含量均表现为：化肥减量配施黄腐酸钾花针期显著高于结荚期和成熟期（P＜0.05），其中25%化肥配施75%生化有机肥处理对提升土壤中有机碳及其组分含量效果最佳，其SOC、DOC、MBC、LOM和ROC含量各生育期分别增加0.15%-13.50%、3.45%-122.11%、15.37%-133.54%、2.56%-60.44%和0.36%-18.80%。

Effects of chemical fertilizer reduction combined with organic fertilizer on soil organic carbon and its components

In order to explore the effects of chemical fertilizer reduction combined with two different fulvic acid potassium organic fertilizers on soil organic carbon and its components, pots were used to simulate field planting, with no fertilization and pure chemical fertilizer as controls, and 100% chemical fertilizer combined with 100% organic fertilizer, 75% chemical fertilizer combined with 25% organic fertilizer, 50% chemical fertilizer combined with 50% organic fertilizer, 25% chemical fertilizer combined with 75% organic fertilizer and 100% organic fertilizer as treatments. The content characteristics of soil organic carbon (SOC), soluble organic carbon (DOC), microbial biomass carbon (MBC), easily oxidized organic carbon (LOM) and inert organic carbon (ROC) in different growth stages were discussed. The results showed that the content of organic carbon and its components in each treatment of chemical fertilizer reduction combined with organic fertilizer was significantly higher than that in podding stage and mature stage, and the content of soluble organic carbon and microbial biomass carbon in podding stage was significantly higher than that in mature stage (P<0.05). The contents of organic carbon and its components in each treatment were as follows: 25% chemical fertilizer combined with 75% biochemical fulvic acid potassium treatment was significantly higher than that of no fertilizer, single fertilizer and single organic fertilizer treatment, 50% chemical fertilizer combined with 50% mineral source fulvic acid potassium treatment was significantly higher than that of no fertilizer, single fertilizer and single organic fertilizer treatment ; the contents of SOC, DOC, MBC, LOM and ROC were 133.0 g·kg-1, 284.4 mg·kg-1, 269.7 mg·kg-1, 30.76 g·kg-1 and 111.2 g·kg-1, respectively. The contents of SOC, DOC, MBC, LOM and ROC were 130.9 g·kg-1, 250.5 mg·kg-1, 251.7 mg·kg-1, 29.86 g·kg-1 and 110.8 g·kg-1, respectively. In summary, the effect of chemical fertilizer reduction combined with biochemical fulvic acid potassium on the content of soil organic carbon and its components was better than that of mineral fulvic acid potassium (P>0.05). The content of organic carbon and its components in each growth period showed that the reduction of chemical fertilizer combined with fulvic acid potassium was significantly higher than that of podding stage and maturity stage (P<0.05). Among them, 25% chemical fertilizer combined with 75% biochemical organic fertilizer treatment had the best effect on improving the content of organic carbon and its components in soil. The contents of SOC, DOC, MBC, LOM and ROC increased by 0.15%-13.50%, 3.45%-122.11%, 15.37%-133.54%, 2.56% -60.44% and 0.36%-18.80%, respectively.