外源性养分对土壤碳氮储量及阳春砂养分吸收效率的影响

Effects of Exogenous Nutrients on Soil Carbon and Nitrogen Storage and Nutrient Absorption Efficiency of Amomum villosum

【目的】基于橡胶-阳春砂生态系统,探究外源养分对林下土壤环境及作物养分转化的影响。【方法】设不施肥(CK)、施农家肥(M)、施化肥(F)、施有机肥+无机肥(O+C)4个处理,连续2年进行养分输入,分析土壤碳氮储量的变化以及影响阳春砂养分吸收效率的主要因素。【结果】自然生长条件下土壤碳、氮储存量和输出量随阳春砂种植年限发生了不同的变化,其中不施肥对照2019年土壤碳、氮储量分别比2017年下降4.08%、3.57%,植物样地上部分碳、氮储量分别显著增加32.03%、40.20%,地下部分碳、氮储量分别显著增加35.47%、42.58%。外源养分的输入加快了作物养分吸收和土壤碳氮固化,与CK相比,M、F、O+C处理总生物量增加显著,增幅分别为5.52%、9.61%和11.89%;M、O+C处理土壤碳储量分别提高9.90%和12.72%,土壤氮储量分别提高2.75%和4.09%,差异显著;O+C处理对土壤养分转化吸收的影响最为明显,土壤碳、氮输出量均表现为O+C>F>M>CK,土壤碳、氮固化量均表现为O+C>M>F>CK。【结论】阳春砂长期林下栽培会造成土壤固有的碳氮储量下降,输入外源养分能有效提升土壤碳氮储量和作物养分吸收效率,维持土壤碳氮库容平衡,其中有机物质起主要促进作用。

【Objective】The effects of exogenous nutrients on the forest soil environment and crop nutrient transformation were explored based on rubber and Amomum villosum intercropping system.【Method】Four treatments were set up in combination with the gradient fertilization experiment:no fertilizer(CK),farmyard manure(M),chemical fertilizer(F),organic fertilizer+compound fertilizer(O+C),and nutrient inputs were carried out for two consecutive years.The change of soil carbon and nitrogen storage and main factors influencing nutrient absorption efficiency of A.villosum under exogenous nutrients were analyzed.【Result】Under natural growth conditions,the soil carbon and nitrogen storage of CK treatment decreased by 4.08%and 3.57%,the above-ground part carbon and nitrogen storage increased significantly by 32.03%and 40.20%,and the underground part carbon and nitrogen storage by 35.47%and 42.58%from 2017 to 2019,respectively.The input of exogenous nutrients accelerated crop nutrient absorption and soil carbon and nitrogen solidification.Compared to CK,it was found M,F and O+C treatments improved total biomass by 5.52%,9.61%and 11.89%,meanwhile,M and O+C treatments improved soil carbon storage by 6.96%and 8.14%and soil nitrogen storage by 3.15%and 3.43%in 2019,respectively,with significant differences.O+C treatment had the most obvious impact on the conversion and absorption of soil nutrients,and the outputs of soil carbon and nitrogen were showed as O+C>F>M>CK,and the amounts of soil carbon and nitrogen solidification were showed as O+C>M>F>CK.【Conclusion】The analysis results show that the longterm understory intercropping of A.villosum will cause the inherent soil carbon and nitrogen storage consumption of the rubber plantation,and exogenous nutrients can effectively increase soil carbon and nitrogen storage and nutrients absorption efficiency and maintain the balance of soil carbon and nitrogen storage.In particular,organic matter plays a positive role in protecting ecological benefits and maintaining sustainable development of soil fertility.