【作者】 刘守龙； 苏以荣； 黄道友； 肖和艾； 吴金水；

【Author】 Liu Shoulong Su Yirong Huang Daoyou Xiao Heai Wu Jinshui Institute of subtropical agriculture CAS Changsha 410125P.R.China

【机构】 中国科学院亚热带农业生态研究所；

【摘要】 本研究利用在亚热带不同典型区域密集取样分析结果对不同区域不同利用方式下土壤碳氮积累的相关关系进行了初步探讨,并分析了其主要的影响因素。结果显示,各样区中不同土地利用方式下土壤有机碳、全氮均具有存在极显著的线性正相关,说明土壤有机碳与氮素具有同消同长的耦合关系。但这种关系并不完全同步,有机碳的变化比氮素更为敏感。沅江、盘塘、大才样区稻田土壤碳氮比分别为9.03、8.28和8.65,总体上呈随有机碳积累而增加的趋势。因此,稻田碳氮比的区域分异可能主要与有机投入有关。但肯福样区可能由于轻视稻田有机肥投入的原因,碳氮比较低(7.91)。在土地利用对碳氮比的影响中也反应了这一点,沅江、盘塘、大才样区稻作对土壤碳氮比影响较小,但肯福稻田土壤碳氮比却显著低于其他利用方式。微生物生物量碳氮比与总量碳氮比区域分异存在明显不同,这与各样区采样时间不同有关。但稻作显著提高了土壤微生物生物量碳氮比,说明淹水可能导致了土壤微生物种群的变化。更多还原

【Abstract】 With high density sampling in the typical regions in subtropical region of China,the coupling re- lationship between soil organic C(SOC)and total N(TN)sequestration under various land uses and the main influencing factors were analyzed.The results showed that there were significant correlations be- tween soil organic C and total N under various land uses,which meant positive coupling relation existing between SOC and TN.But the sequestration of SOC and TN were not with the same step,the changes of SOC were more rapid that that of TN.The C:N in YJ,DC,PT and KF were 9.03,8.65,8.28,7.91, respectively.C:N ratio increased with the SOC contents generally.The regional discrepancy of C:N ra- tio was probably due to the organic matter input.Rice cultivation has not obvious influence on soil C:N in 3 typical regions except KF for which the C:N of paddy soils were lower than other land uses.In KF,the ratio of paddy soil area was small,thus farmers usually ignored the application of organic manure in paddy soils.The regional discrepancy of microbial biomass C:N was different with soil C:N,that was due to the sampling time.Microbial biomass C:N was more sensitive to changes of surroundings including the application of organic matter,air temperature,soil water content and plant growth.But rice cultivation in- creased the soil microbial biomass C:N compared with other land uses,that indicated water-logged condi- tion may caused the changes of microbial community.更多还原