摘要
土地沙漠化一直是影响宁夏生态建设和农业生产的主要问题之一。为探讨林木枝条对沙化土壤的改良效果,以当地农田防护林所产生的林木枝条为原料,在2011年10月至2013年10月期间研究了土壤翻埋杨树粉碎枝条(chips incorporation,CI)、覆盖杨树粉碎枝条(chips mulch,CM)、翻埋杨树粉碎枝条+覆盖未粉碎的柳树枝条(chips incorporation plus branches mulch,CI+BM)和不做任何处理的对照(control,CK)对宁夏沙化土壤理化性状和生物学特性的影响。结果表明,CI和CI+BM与CK相比,2012年和2013年均增加了土壤总孔隙度、田间持水率、有机碳、有效磷和速效钾含量(P<0.05),提高了土壤呼吸强度、微生物数量(细菌、真菌和放线菌)和酶活性(脲酶、过氧化氢酶)(P<0.05),降低了土壤密度(P<0.05);2013年CI和CI+BM进一步增加了土壤全氮、全磷和水解氮含量(P<0.05),但同时也增加了土壤全盐含量(P<0.05)。CM与CK相比,2012年和2013年均显著增加了土壤有效磷和速效钾含量(P<0.05),提高了土壤呼吸强度和酶活性(P<0.05);2013年CM处理的土壤p H值、全氮和水解氮含量亦显著增加(P<0.05)。相关分析结果显示,沙化土壤性质的改善与土壤中有机碳含量的增加密切相关,处理间土壤有机碳含量CI+BM>CI>CM>CK,表征土壤质量的综合指数表现出同样的趋势:2012年分别为0.907、0.678、0.259和0.105,2013年分别为0.926、0.828、0.258和0.136。该研究为当地及中国北方干旱半干旱地区沙地生态治理及农业生产提供了可借鉴的案例,同时也为促进林木废弃物的资源化利用提供理论基础。
Desertification is one of most serious problems which affect eco-construction and agricultural production in Ningxia and other arid and semiarid areas in China. To study the effects of tree branch application patterns on physicochemical property and microbial activity of desertified soil, pruned tree branches were collected as soil amended materials from local common trees of farmland shelterbelt, and a two-year study was conducted from October 2011 to October 2013 in Yinchuan Belly Desert of Ningxia. Four experimental treatments were set up, including 1） CK （no tree branches applied）, 2） CI （5% （w/w） grinded poplar branch chips incorporated into 0-20 cm soil layer）, 3） CM （grinded poplar branch chips mulched on soil surface with a thickness of about 3 cm） and 4） CI＋BM （5% （w/w） of grinded poplar branch chips incorporated into 0-20 cm soil layer plus ungrinded willow branches crisscross mulched on soil surface with a thickness of 30-40 cm and a coverage of 50%-60%）. The 0-20 cm soils were sampled and measured in October 2012 and October 2013 respectively. Results showed as follows： To physical properties, compared with CK, CI and CI＋BM decreased bulk density yet increased total porosity and field water holding capacity of desertified soil in 2012 and 2013 （P〈0.05）, and there was no significant difference between the two on other physical properties except CI＋BM had more effect on increasing total porosity than CI in 2013; CM significantly increased total porosity in 2012 （P〈0.05）, but had no effect on other indicators of physical properties compared with CK in 2012 and 2013. To chemical properties, compared with CK, both CI and CI＋BM increased organic carbon, available phosphorus （P） and available potassium （K） in 2012 and then increased total salt, organic carbon, total nitrogen （N）, total P, alkaline N, available P and available K in 2013 （P〈0.05）, yet had no effects on pH value （P〉0.05）; furthermore, CI＋BM had more effect on increasing total N than CI in 2013; compared with CK, CM increased total available P and available K in 2012 and then increased pH value, total N, alkaline N, available P and available K in 2013 （P〈0.05）, yet had no effect on other chemical properties compared with CK （P〉0.05）. To biological properties, it showed an order of CI＋BM 〉 CI 〉 CM 〉 CK on enhancing microbial activity, CI and CI＋BM enhanced soil respiration, microbial number, urease activity and catalase activity compared with CK in 2012 and 2013 （P〈0.05）, and CI＋BM tended to have more effect on enhancing microbial activity than CI; and also compared with CK, CM also increased soil respiration, urease activity and catalase activity in 2012 and 2013 （P〈0.05）, as well as increased bacteria and fungi number in 2012, yet had no effect on microbial number in 2013. An analysis indicated that soil physical, chemical and biological properties were improved in 2013 than in 2012. Additionally, a correlation analysis indicated that most of measured soil indicators were significantly or highly significantly correlated with organic carbon content （except pH value and total K in 2013）, and organic carbon content presented a tendency of CI＋BM 〉 CI 〉 CM 〉 CK among treatments in 2012 and 2013; a comprehensive index SQI （soil quality index）, which was applied for assessing soil quality, also presented a tendency of CI＋BM 〉 CI 〉 CM 〉 CK in 2012 （0.907, 0.678, 0.259 and 0.105 respectively ） and 2013 （0.926, 0.828, 0.258 and 0.136 respectively）. In summary, all tree application patterns have positive effects on improving soil properties or quality during experimental period, which presents a tendency of CI＋BM 〉 CI 〉 CM 〉 CK among treatments. Above study provides a successful case for ecological management and agricultural production for Ningxia and other arid and semiarid areas of North China; meanwhile it also may be beneficial to tree branch recycling and utilization.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第10期174-181,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家林业公益性行业科研专项(201304311)
国家国际合作专项(2015DFA90900)
"948"项目(2013-04-79)
关键词
土壤
生态
有机碳
林木枝条
施用方式
改良效果
宁夏
soils
ecology
organic carbon
tree branches
application patterns
improvement effect
Ningxia
