水田改果园后土壤性质的变化及其特征  

Effects of land-use change from paddy field to orchard farm on soil property shift processes and their characteristics

作　　者：杨东伟[1] 章明奎[1] 

机构地区：[1]浙江大学环境与资源学院,杭州310058

出　　处：《生态学报》2015年第11期3825-3835,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41071145)

摘　　要：近年来,水田改作经济林地,在我国南方地区非常普遍。为深入了解这一转变对土壤质量的影响,以浙江省典型水稻土(青粉泥田)及其改果园不同年限的系列表层土壤(0—15 cm)为研究对象,应用磷脂脂肪酸生物标记等方法,研究了水田改果园后土壤理化性质和微生物群落结构等性质的变化以及它们之间的关系。结果表明,水田改果园后,土壤中大于0.25 mm水稳定性团聚体、盐基饱和度、p H值、有机质、全氮和碱解氮等随着改果园年限的延长而显著降低(P<0.05)。土壤微生物生物量碳氮、微生物商和土壤呼吸强度随改果园年限增加而显著下降(P<0.01)。土壤微生物群落结构也发生明显变化:磷脂脂肪酸总量显著降低(P<0.01),微生物种类减少,原生动物在土壤微生物中所占比例增加,革兰氏阴性细菌与革兰氏阳性细菌比值降低(P<0.01),好氧细菌/厌氧细菌和甲烷氧化菌/细菌增加(P<0.01),表征养分胁迫的环丙基脂肪酸/前体物和异式脂肪酸/反异支链脂肪酸显著增加(P<0.01)。冗余分析表明,土壤含水率、有机质和碱解氮是决定水田和果园土壤微生物群落结构差异的最重要因子(P<0.01);改果园后,土壤微生物群落结构发生了阶段性变化,不同利用方式对微生物群落结构的影响程度要大于同一利用方式耕作不同年限对微生物群落结构的影响。研究表明,水田改果园后土壤理化性质以及生物学性质发生退化,土壤质量下降;而水田中微生物数量和种类都比较丰富,因而认为水田是土壤(地)可持续利用的一种有效方式。Studies of the effects of land-use change on soil physicochemical properties,microbial community structure and other biological properties are important for understanding changes in soil quality in agricultural soils. A diverse soil microbial community is an important measure of sustainable land use,and soil microbial community structure and diversity are sensitive indicators of soil quality. In recent years,land-use change from paddy field to economic forest land has been very common in the south of China. In order to recognize the effects of this land-use change on soil quality,a study was conducted,in Zhejiang province,on paddy and orchard surface soil（ 0—15 cm）. Multivariate analyses including phospholipid Fatty Acids（ PLFAs） were employed to determine the changes in soil environmental factors,microbial community structure and their relationships after land-use change from paddy fields to orchard farms. Water-stable aggregates（〉 0. 25 mm）,pH,organic matter（ OM）,base saturation（ BS）,total nitrogen（ TN）,Alkali-hydrolysable nitrogen（ AHN） decreased after land-use change from paddy to orchard soils,and they had significant negative correlations with orchard age（ P〈0. 05）. Enhancement of organic carbon mineralization and reductions in plant residues in the soil caused the decline in soil organic matter content which resulted in a reduction in water-stable aggregates（ 〉0. 25 mm） andtotal nitrogen. The increase in nitrification also led to a reduction in alkali hydrolyisable nitrogen. The extensive application of acidic fertilizer and enhancement of nitrification increased soil acidification（ caused by H＋）. Microbial biomass carbon（MBC）,microbial quotient（q MB） and soil respiration（Resp） decreased,and had significant negative correlations with orchard ages（ P〈0. 01）. The changes in biological properties could be due to decreased soil moisture,OM and other soil characteristics. During the change from paddy field to orchard farm,soil microbial communi

关 键 词：土地利用方式 土壤性质 微生物群落结构 磷脂脂肪酸 土壤质量 

分 类 号：S151.9[农业科学—土壤学]