灌溉方式对设施土壤总有机碳及其腐殖质组分的影响

通过13年连续的番茄栽培灌溉试验,分析了沟灌、滴灌和渗灌3种灌溉处理0—80cm土层土壤有机碳及其腐殖质组分(胡敏酸、富里酸、胡敏素等)含量,探讨了不同灌溉方法对温室土壤有机质变化的影响。结果表明:3种灌溉处理土壤总有机碳、腐殖质各组分含量剖面变化特征一致,均随土层加深而降低,且这一变化主要集中在0—50cm土层,50—80cm土层变化较小。土壤总有机碳及其组分各灌溉处理间差异明显,将土壤剖面分为0—20,20—80cm上、下2个层次,总体上总有机碳含量上层为渗灌沟灌滴灌,下层滴灌沟灌渗灌;腐殖酸含量上层滴灌沟灌渗灌,下层为渗灌滴灌沟灌;胡敏素上层为沟灌滴灌渗灌,下层为渗灌滴灌沟灌。滴灌处理既能使0—40cm土层土壤有机碳含量保持较高水平,土壤腐殖质含量又高于沟灌、渗灌处理,这对于提升设施土壤肥力水平、保证番茄养分供应是有利的。

Effects of Irrigation Methods on Total Organic Carbon and Humus Components of Greenhouse Soil

Soil organic carbon (SOC) and humus components (humic acid,fluvic acid,and humin etc.) in the soil layer of 0-80 cm under three irrigation modes (furrow irrigation,drip irrigation and subsurface irrigation) were studied through 13 years of continuous tomato cultivation irrigation experiment.And the effect of irrigation methods on the properties of soil organic matters in greenhouse was evaluated.The results demonstrated that SOC content and the contents of humus components in three treatments declined with the increasing of soil depths.This kind of change mainly concentrated in the 0-50 cm soil layer,and the change in 50-80 cm soil layer was less.However,the SOC and its components were significant different among irrigation methods.The soil profile was divided into two layers,the upper (0-20 cm) and the lower (20-80 cm).The total SOC contents in the upper layer of three irrigation methods was in the order of subsurface irrigation ＞ furrow irrigation ＞ drip irrigation,and in the lower layer the order was drip irrigation ＞ furrow irrigation ＞ subsurface irrigation.For soil humus acid contents of three irrigation methods,in the upper layer the order was drip irrigation ＞ furrow irrigation ＞ subsurface irrigation,and in the lower layer,the order was subsurface irrigation ＞ drip irrigation ＞ furrow irrigation.For soil humin contents of three irrigation methods,in the upper layer the order was furrow irrigation ＞ drip irrigation ＞ subsurface irrigation,and the humin content in the lower layer was in the order of subsurface irrigation ＞ drip irrigation ＞ furrow irrigation.Drip irrigation could make the SOC content remain at a high level in the 0-40 cm soil layer,and soil humus content was higher than that of the other two irrigation methods,and this was beneficial to improve the soil fertility level and ensure the nutrient supply of tomato.