绿洲灌溉区与旱作区多龄苜蓿地土壤有机碳、氮及物理特性分析

以甘肃灌区和旱作区苜蓿(Medicago sativa)地土壤为研究对象,对不同地域的苜蓿地土壤全氮(TSN)、有机碳(SOC)、容重、含水量进行测定,结果表明:灌区SOC含量均高于旱作区,在90~100cm土层其含量与旱作区差值最大,达3.41g/kg。在0~100cm灌区SOC含量为6.81~12.49g/kg,均值为9.25g/kg,比旱作区高22%。旱作区TSN含量随土壤深度的增加而减小,含量在(1.03±0.01)~(0.44±0.04)g/kg。在0~30cm灌区TSN含量相对较稳定,差异不显著(P0.05),在30~60cm剖面全氮含量急剧下降,70~100cm含量变化较为稳定,TSN含量维持在(0.66±0.01)g/kg。旱作苜蓿地土壤含水量在0~60cm变化不显著(P0.05),0~100cm土壤含水量均值为(14.437±1.124)%,灌区苜蓿地土壤含水量均值为(16.025±2.029)%。随着土壤深度的增加,旱作区和灌区苜蓿地土壤容重均呈现依次增大的分布规律,旱作区最大值为(1.421±0.034)g/cm,比最小值高出17.5%,灌区最大值(1.332±0.017)g/cm,比最小值高出11.3%.

Analysis of the organic carbon,total nitrogen and physical property in the soil of alfalfa land in oasis irrigating region and dry farming regions

The soil of alfalfa land in the irrigating and dry farimg regions was sampled and the soil organic carbon (SOC),soil total nitrogen (STN),soil bulk (SB)and soil moisture (SM)were measured.The resulted showed that the SOC in the irrigating regions (IR)were higher than that in the dry farming regions (DFR), there was a biggest difference (3.41 g/kg)in l depth from 90 to 100 cm between IR and DFR.The value of SOC in depth from 0 to 100 cm in IR was 6.81~12.49 g/kg,the mean was 9.25 g/kg,which was higher than that in DFR.The content of STN was decreased with increasing of the soil depth,the scale of STN content in the soil was from 0.44±0.04 g/kg to 1.03±0.01 g/kg.The content of STN in depth from 0 to 30 cm was relative sta-bility,which no significant difference (P >0.05).The content of STN was decreased from 30 to 60 cm,howev-er,the value of TSN (0.66±0.01 g/kg)was kept stability from 70 to 100 cm.There was no significant differ-ence in the conten of SM from 0 to 60 cm in the soil of DFR(P <0.05).The mean value of the soil from 0 to 100 cm was 14.437 ± 1.124.The mean vaue of the soil in the alfalfa land in IR was 1 6.025±2.029.With increas-ing of soil depth,the SB in IR and DFR was increasesd the maximum value in DRF was 1.421 ±0.034,which was 17.5% higher than the minimum value in the soil.The maximum value in IR was 1.332±0.017,which was 1 1.3% higher than the minimum value in the soil.