长期施肥对土壤颗粒有机碳和酶活性的影响

为探讨长期不同施肥条件下土壤颗粒有机碳和土壤酶活性的变化及其关系,对棕壤肥料长期定位试验地第27年耕层土壤的颗粒有机碳和主要酶活性进行了测定与分析。结果表明:长期施用有机肥显著提高土壤中的总有机碳(TOC)、游离态颗粒有机碳(FPOM-C)和闭蓄态颗粒有机碳(OPOM-C)含量及土壤颗粒有机碳POM-C/TOC和FPOM-C/OPOM-C。单施化肥使土壤的TOC含量有所增加,但显著降低了FPOM-C和OPOM-C含量及POM-C/TOC和FPOM-C/OPOM-C;长期施用有机肥显著提高土壤的过氧化氢酶、转化酶、脲酶和中性磷酸酶活性,且均随有机肥用量的增加而增加。单施化肥对土壤酶活性影响差异较大。相关分析结果显示:土壤的TOC、POM-C、FPOM-C和OPOM-C含量两两之间均呈现显著或极显著相关关系;土壤的TOC、POM-C、FPOM-C和OPOM-C含量与过氧化氢酶、转化酶、脲酶和中性磷酸酶活性之间存在密切关系。

Effect of Long-term Fertilizations on Particulate Organic Carbon and Enzyme Activities in a Brown Earth

Particulate organic carbon(POM-C) and enzyme activities in soil at 0-20cm depth of long-term located fertilizer experiment field for 27 years were measured and analyzed in order to illustrate the changes of POM-C and enzyme activities in soil and the relationship between them under different fertilizations.The results indicated that long-term application of pig manure significantly increased content of TOC,FPOM-C and OPOM-C in soil and the ratios of POM-C/TOC and FPOM-C/ OPOM-C.Application of chemical fertilizer alone increased soil TOC content but significantly decreased soil FPOM-C and OPOM-C contents and the ratios of POM-C/TOC and FPOM-C/ OPOM-C.Long-term application of pig manure significantly raised soil catalase,invertase,urease and neutral phosphatase activities.The soil enzyme activities were differently influenced by application of chemical fertilizer alone.The correlation analysis results showed that there were significant or extremely significant positive correlation relationship among the different SOC fractions and intimate relationship between the different SOC fractions and the soil enzyme activities.