廣西杉木連栽幼林根際與非根際土壤特性研究

覃祚玉 鄧小軍 ??宋賢沖 王會利+余東威??何彥然 ??唐健 ????

摘要：采用配對樣地法對廣西連栽杉木幼林不同栽植代數(shù)（一代林G1、二代林G2）的根際土和非根際土進(jìn)行了土壤特性的分析研究，為連栽杉木人工林經(jīng)營與可持續(xù)發(fā)展提供理論依據(jù)。結(jié)果表明：土壤pH值、有機(jī)質(zhì)、全N、全P、水解性N、有效P、速效K、交換性Ca2+、有效Fe、有效Mn含量均表現(xiàn)為G2>G1，根際土（R）>非根際土（S），而土壤全K含量則反之。杉木連栽對林地土壤養(yǎng)分狀況、酶活性和微生物具有一定影響。土壤酶活性表現(xiàn)為G2>G1，根際土（R）>非根際土（S）。無論是在根際土還是非根際土，土壤微生物優(yōu)勢種均為細(xì)菌，微生物總數(shù)、細(xì)菌、放線菌、真菌數(shù)量表現(xiàn)為G1>G2；栽植代數(shù)增加，細(xì)菌所占微生物總數(shù)比例下降，而放線菌所占比例則有明顯增加趨勢。

關(guān)鍵詞：杉木； 連栽； 養(yǎng)分狀況； 微生物； 酶活性

中圖分類號：S791.27文獻(xiàn)標(biāo)識碼：A文章編號：1004-3020（2017）02-0010-05

Rhizosphere and Nonrhizosphere Soil Properties Analysis of

Cunninghamia lanceolata

Plantations Under Different Rotations of Continuously Planting in Guangxi

Qin Zuoyu（1，2，3）Deng Xiaojun（1，2，3）Song Xiancong（1，2，3）Wang Huili（1，2，3）Yu Dongwei（4）He Yanran（4）Tang Jiang（1，2，3）

（1.Guangxi Zhuang Autonomous Region Forestry Research Institute Key Laboratory of Central SouthNanning530002；

2.China Fastgrowing Timber Cultivation of Forestry Ministry of ChinaNanning530002；3.Guangxi Key Laboratory

of Superior Timber Trees Resource CultivationNanning530002；4.Department of Forestry

of Guangxi Zhuang Autonomous RegionNanning530028）

Abstract： In order to provide the theoretical basis for the successive Cunninghamia lanceolata plantation management and sustainable development，rhizosphere and nonrhizosphere soil properties between the first and the second generation Cunninghamia lanceolata plantation in Guangxi were studied though the pair method. Results showed that the pH value，the contents of soil organic matter， total nitrogen， total phosphorus， alkali solution nitrogen， available phosphorus， available potassium， exchange of calcium ion， available Fe and available Mn of the second generation Cunninghamia lanceolata plantation was higher than the frist one， thoes nutrient content of rhizosphere soil（R） was higher than nonrhizosphere soil（S）， but the content of soil total K has an opposite trend. Continuously planting has a certain influence on soil enzyme activity， soil nutrient content and microbial. The second generation in the soil enzyme activity was higher than the first one， rhizosphere soil enzyme activities values were higher than the nonrhizosphere soil. Whether the rhizosphere soil or nonrhizosphere soil， the dominant species of soil microbes was bacteria.The proportion of microbes， the proportion of bacteria， the proportion of actinomycetes and the proportion of fungi showed that the first generation of forest soil>the second generation of forest soil； The proportion of bacteria decreased with continuousplanting rotation decreasing，but the proportion of actinomycetes showed a increasing tend.

Key words：Cunninghamia lanceolata；the continuous cropping； soil nutrient content；microorganism； enzyme activity

人工林地（特別是速生豐產(chǎn)林）衰退現(xiàn)象現(xiàn)已成為全球性關(guān)注問題。中國主要造林樹種北方的楊樹Populus 、南方的桉樹Eucalyptus 均存在地力衰退現(xiàn)象，其中胡興宜等[1-3]、葉紹明等[4-6]分別對楊樹、桉樹連栽林下物種多樣性、土壤養(yǎng)分及其生物循環(huán)特征等方面的研究結(jié)果顯示：連栽使得這幾方面均有不同程度的下降趨勢。杉木Cunninghamia lanceolat是中國主要的用材樹種之一（19°30′～34°03′N；101°30′～121°53′E） ，廣泛分布于16 個省區(qū)，具有速生、豐產(chǎn)、材性好、生態(tài)價值高等優(yōu)良特性[7]。根際土壤是植物—土壤—微生物及其環(huán)境相互作用的活動場所，同時也是養(yǎng)分、有益/有害物質(zhì)及水分進(jìn)入植株參與物質(zhì)與能量循環(huán)的門戶，直接影響著植株的生長發(fā)育[8]。目前杉木林……