施肥措施对古香榧林地土壤活性有机碳和养分的影响

Effects of Fertilization Measures on Soil Labile Organic Carbon and Nutrient of Old Torreya grandis

[目的]探讨不同施肥措施下香榧林土壤的培肥效果,为古香榧林科学施肥提供参考。[方法]以浙江省诸暨市香榧国家森林公园古香榧林地为研究对象,通过野外采集土壤样品,分析不同施肥处理香榧林地0～20、20～40、40～60 cm土层土壤总有机碳(TOC)、易氧化碳(ROC)、轻组有机质(LFOM)及土壤养分含量。[结果]研究表明:(1)与不施肥(CK)相比,有机-无机配施(CF+FM)处理可显著增加各土层土壤TOC、ROC、LFOM、全氮(TN)和水解性氮(AN)含量;单施复合肥(CF)处理可增加各土层土壤速效钾(AK)以及表层土壤ROC、LFOM和AN含量,对AK的提升作用较为显著;两者均可显著提高土壤有效磷(AP)含量,但CF处理效果不及CF+FM处理。(2)CF+FM处理可在一定程度提高土壤pH值,但结果差异不显著;CF处理可显著降低土壤pH值。(3)各土层土壤ROC/TOC均表现为:CF+FM处理>CF处理>CK处理,但仅在表层土壤CF+FM处理显著高于CK处理。(4)相关性分析表明:ROC、LFOM与TOC间的相关性均达到极显著水平,三者与TN、AN、AP、AK间的相关性均达到显著或极显著水平。[结论]农民惯用的有机-无机配施处理较单施复合肥处理更有利于土壤有机碳和土壤养分的积累。

[Objective] To reveal the effects of different fertilization measures on soil fertility, and provide a reference for fertilization of old Torreya grandis.[Method] Three different fertilization treatments (non-fertilizer (CK), chemical fertilizer plus farmyard manure (CF+FM), and chemical fertilizer treatment (CF) were carried out in the Chinese Torreya National Forest Park in Zhuji, Zhejiang Province. Soil samples were collected from the field to analyze the total soil organic carbon (TOC), readily oxidizable carbon (ROC), light fraction organic matter (LFOM), and soil nutrient contents in 0-20, 20-40, and 40-60 cm soil layers.[Result](1) Compared with the CK, the contents of TOC, ROC, LFOM, total nitrogen (TN), and available nitrogen (AN) in soil layers increased significantly under CF+FM treatment. The contents of ROC, LFOM and AN in the topsoil and the soil available potassium (AK) in each soil layer increased under CF treatment, especially AK. The effect of CF treatment on the increase of soil available phosphorus (AP) content was far less than that of CF+FM treatment.(2) Soil pH increased insignificantly under CF+FM treatment, while decreased significantly under CF treatment.(3) The ratios of ROC to TOC in three soil layer for different fertilization treatments showed:CF+FM > CF > CK, but only CF+FM treatment in surface soil was significantly higher than that of CK.(4) Correlation analysis showed that ROC, LFOM and TOC were extremely significantly correlated. The TOC, ROC and LFOM were significantly or extremely significantly correlated with TN, AN, AP, AK.[Conclusion] The organic-inorganic combination treatment is more conducive to the accumulation of soil organic carbon and soil nutrients than the single application of chemical fertilizer treatment.