CAJ | 학술논문

于2007年以不同连作年限棉田为研究对象，研究分析连作5 a、8 a、12 a年和15 a棉田土壤容重、土壤氮、磷、钾养分及微生物区系的变化规律，以揭示长期连作造成棉田减产的主要因素。研究结果表明：在棉农自主经营管理条件下，棉田土壤容重并未随着连作年限的增加呈现有规律的变化。随着连作年限的增加土壤速效磷、全氮、全钾含量均呈下降趋势，土壤有机质以及土壤速效钾含量则是连作8a之后随着连作年限的增加呈下降趋势。随着连作年限的增加，棉田土壤微生物总量呈明显的下降趋势，连作8 a、12 a、15 a棉田的土壤微生物总数平均值分别比连作5 a的下降了40．1％、46．7％、52．4％，而且微生物菌群结构也发生了变化，总体表现为细菌和放线菌数量减少，真菌数量增加的发展态势。
우2007년이불동련작년한면전위연구대상，연구분석련작5 a、8 a、12 a년화15 a면전토양용중、토양담、린、갑양분급미생물구계적변화규률，이게시장기련작조성면전감산적주요인소。연구결과표명：재면농자주경영관리조건하，면전토양용중병미수착련작년한적증가정현유규률적변화。수착련작년한적증가토양속효린、전담、전갑함량균정하강추세，토양유궤질이급토양속효갑함량칙시련작8a지후수착련작년한적증가정하강추세。수착련작년한적증가，면전토양미생물총량정명현적하강추세，련작8 a、12 a、15 a면전적토양미생물총수평균치분별비련작5 a적하강료40．1％、46．7％、52．4％，이차미생물균군결구야발생료변화，총체표현위세균화방선균수량감소，진균수량증가적발전태세。
Continuous cropping practice (CCP) affects soil physical and chemical properties ,vegetation growth and yield .However ,few study were conducted on cotton .Elucidation of CCP effects is of importance for the sustainable cot-ton production in North Xinjiang .Field experiments were conducted on cotton fields with 5 a ,8 a ,12 a ,and 15a crop-ping durations .Soil samples were collected at depths of 0~30 cm .Soil properties such as soil bulk density (BD ) ,or-ganic matter (OM ) ,available nitrogen (AN ) , available phosphorous (AP ) ,available potassium (AK ) , total nitrogen (TN) ,total phosphorous (TP) ,and total potassium (TK) were measured ,and microflora were investigated .The results showed that BD had no consistent temporal patterns of variation across all treatments .AP ,TK ,and TN progressively de-creased with growth stage ,while OM and AK did not show the same trends until after 8a CCP .CCP had negative effects on soil microflora .The number of microflora decreased by 40 .1% ,46 .7% ,and 52 .4% after 8 a ,12 a and 15 a CCP , respectively .Furthermore , the number of bacteria and actinomycetes decreased whereas the fungi increased as growth stage progressed .The ratios of bacteria to fungi (B/F ) and actinomycetes to fungi (A/F ) showed a diminishing trend , indicating the degradation in soil fertility by continuous cropping .