轮作与施肥对滁菊连作土壤微生物特性的影响

Effects of crop rotation and bio-organic manure on soil microbial characteristics of Chrysanthemum cropping system

为探讨轮作模式与生物有机肥施用对滁菊连作土壤微生物特性的影响,以滁菊、小麦为研究对象,采用田间试验,设置滁菊连作模式、常规滁菊小麦轮作模式和滁菊小麦轮作模式配施生物有机肥(200 kg·667 m-2)3种处理,测定土壤化学性状、土壤微生物量碳氮和土壤微生物数量指标.结果表明:与连作模式相比,常规菊麦轮作模式与菊麦轮作配施生物有机肥模式的土壤p H值,有机质、碱解氮、速效磷与速效钾含量,土壤微生物生物量氮(MBN)、碳(MBC)、微生物熵,以及土壤细菌、真菌和放线菌数量增加,土壤MBC/MBN值和真菌占三大菌群总量的比值降低.在试验条件下,以滁菊小麦轮作配施200 kg·667 m-2生物有机肥效果最佳,土壤有机质含量为15.62 g·kg-1,碱解氮、速效磷和速效钾含量分别达到为64.75、83.26和96.72 mg·kg-1,微生物生物量氮、碳为217.40和38.41 mg·kg-1,细菌、真菌、放线菌数量分别为22.31×106、56.36×103、15.90×105cfu·g-1.合理轮作和增施生物有机肥可改善土壤酸化状况、土壤肥力和土壤微生物群落结构,增加土壤养分有效供给,对减轻连作障碍具有积极作用.

We conducted a field experiment to evaluate the effects of rotation system and bio-organic manure on soil microbial characteristics of Chrysanthemum cropping system. Taking Chrysanthemum morifolium Ramat and wheat as experimental plants, treatments under Chrysanthemum continuous cropping system （M1 ）, conventional Chrysanthemum-wheat rotation system （M2 ）, and Chrysanthe- mum-wheat rotation system receiving bio-organic manure application of 200 kg · 667 m-2 （ M3 ） were designed. Soil chemical properties, soil microbial biomass carbon （MBC） and nitrogen （MBN） , and the amounts of different types of soil microorganisms were determined. Results showed that compared with M1, treatments of M2 and M3 significantly increased soil pH, organic matter, available N, P, and K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, but decreased the ratio of MBC/MBN, and the relative percentage of fungi in the total amount of micro- organisms. Treatment of M3 had the highest contents of soil organic matter, available N, available P, available K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, with the values being 15.62 g · kg-1, 64.75 mg · kg-1, 83.26 mg· kg-1, 96.72 mg · kg-1, 217.40 mg · kg-1 38.41 mg · kg-1 22.31·106 cfu · g-1 56.36·103 cfu · g-1 15.90·105cfu . g-1 respectively. We concluded that rational crop rotation and bio-organic manure application could wea- ken soil acidification, improve soil fertility and microbial community structure, increase the efficiency of nutrition supply, and have a positive effect on reducing the obstacles of continuous cropping.