延边地区三种类型植烟土壤酶活力、速效养分根际效应研究

Study on Tobacco Rhizosphere Effects of Soil Enzyme Activities and Available Nutrients in Three Soil Types in Yanbian

在大田环境条件下,采用随机区组设计,研究延边地区3种类型土壤烤烟全生育期根际和非根际土过氧化氢酶、脲酶和转化酶活性,pH值,碱解氮、速效钾和速效磷含量动态变化。结果表明:延边地区植烟土壤根际土过氧化氢酶、脲酶和转化酶活性平均为0.60U,0.48U和22.09U,根际效应在不同土壤酶间存在差异:过氧化氢酶(R/S=1.08)<脲酶(R/S=1.14)<转化酶(R/S=1.51)。暗棕壤烟株根际土3种酶活性和酶活根际效应均高于其他两种类型土壤。烟株根际土pH值、碱解氮、速效磷和速效钾含量分别为5.42、72.52 mg/kg、33.36 mg/kg和402.04 mg/kg,根际效应表现为:pH(R/S=0.91)<碱解氮(R/S=0.98)<速效磷(R/S=1.99)<速效钾(R/S=2.46)。烟株根际土pH值、碱解氮和速效钾含量均表现为:暗棕壤>黑砂土>白浆土,根际土速效磷含量与此相反。结论:暗棕壤烟株根际效应较大,酶活性较高、养分富集较多,为烟株生长提供了良好的养分供应环境,是暗棕壤烟叶质量优于黑砂土和白浆土的原因之一。

In this study, three types of.soil and flue cured tobacco of Yanbian area with randomized block design in the field were used to investigate the activities of catalase, urease and invertase, and the contents of alkali-hydrolyzable N, available P and K in rhizosphere and non-rhizosphere soils, and pH values, soil enzymes and nutrients at different developmental stages of tobacco plant. Results indicated that the average activities of catalase, urease and invertase in rhizosphere soils for planting tobacco were 0.60U, 0.4gu and 22.09U, respectively. The rhizosphere effect of soil enzyme were obvious different, i.e. catalase （R/S=1.08）〈urease （R/S = 1.14）〈invertas （R/S=1.51）. pH value and the contents of alkali-hydrolyzable N, available P and K of rhizosphere soils were 5.42, 72.52 mg/kg, 33.36 mg/kg and 402.04 mg/kg, respectively. The rhizosphere effect was in an order ofpH （R/S =0.91 ） 〈 alkali-hydrolyzable N （R/S =0.98） 〈available P （R/S =1.99） 〈available K （R/S=2.46）. pH value and the contents of alkali-hydrolyzable N, available P and K in rhizosphere and non-rhizosphere soils were in an order of dark brown soil〉black sandy soil〉albic Soil. Therefore, dark brown soil had higher rhizosphere effect and could provide more favorable environment including nutrition for planting tobacco, which might be one of the important reasons that dark brown earths was better than other two soils for tobacco growth.