长期培肥对烤烟-小麦轮作红壤各级团聚体氮及其酶活性的影响

以云南省烟草农业科学研究院研和试验基地13年长期定位试验为平台,以化肥配施有机肥(CFM)、单施化肥(FM)和不施肥(CK,对照)3种处理土壤为研究材料,利用干筛法分离土壤团聚体,研究长期培肥对烤烟-小麦轮作红壤团聚体、有机质、氮含量、酶活性的影响及其相关性。结果表明:长期化肥配施有机肥有利于大团聚体的形成,2～1mm团聚体土壤的分配率显著高于单施化肥和对照;使耕层土壤有机质、各形态氮(全氮、碱解氮、硝态氮和铵态氮)及酶活性大幅度改善,并且,除硝态氮以外,各级团聚体土壤有机质及各形态氮含量变化趋势为CFM>CF>CK;化肥配施有机肥各级团聚体土壤蛋白酶、脲酶、蔗糖酶、脱氢酶活性明显高于单施化肥和对照,其中脲酶、蔗糖酶活性与土壤有机质和4种形态氮呈显著正相关,蛋白酶和脱氢酶与上述营养呈负相关,但不显著。化肥配施有机肥有利于增加土壤大团聚体的分配率,提高土壤有机质、全氮及碱解氮等的含量及酶活性,对烤烟、小麦生长意义重大。

Influence of the Long-term Fertilization on Nitrogen and Enzymatic Activities in Aggregates of Tobacco-Wheat Grown Red Soil

Soil samples,which were treated with combined application of fertilizers and organic manure(CFM),application of fertilizer manure(FM) and no fertilization(CK),respectively,were collected from Yanhe test site of Yunnan Academy of Tobacco Agricultural Science for 13 years located experiment.Distribution of soil aggregates,organic matter and nitrogen concentrations,and enzyme activities of tobacco-wheat grown red soils for long-term fertilization were investigated by dry sieving method for soil aggregates.The aim was to evaluate whether long-term fertilization influenced tobacco-wheat grown red soils,and their relationships.Distribution rate of soil macroaggregates(2~1 mm) for long-term CFM compared with CF and CK could be significantly increased.Content of organic matter,multi-form N(total N,NO-3-N,NH+4-N and alkali-N) and enzyme activities of the soils for long-term CFM could be significantly improved and change of organic matter,multi-form N of soil aggregates was CFM >CF >CK,besides NO-3-N.The protease,urease,invertase and dehydrogenases activities in different aggregates soil for long-term CFM compared with long-term CF and CK were significantly increased and the urease and invertase activities were positively correlated with organnic matter and four forms of N,in contrary,others were negative correlation,but insignificant.To increase distribution rate of soil macroaggregates,improve organnic matter of soils,concentrations of total N and alkali-N,and increase the activity of soil enzymes will play an important role in the tobacco-wheat grown.