| 摘要: |
| 以玉米秆为材料，研究了荒漠生态系统下残茬的腐解率和腐解物的有机C、N、K的含量、养分释放率及C/N的变化。结果表明,累积腐解率和有机C的分解率随时间的延长呈上升的趋势，0～46 d和46～92 d残茬腐解率分别为34.6%和11.9%，残茬有机C的分解率分别为34.9%和12.5%。腐解残留物的有机C、N和K的含量存在不同的变化规律，随时间的推移，有机C的含量先缓慢下降，184～350 d基本不变，然后又缓慢下降；氮含量则是先逐渐上升，138 d后基本不变；K含量在0～46 d迅速下降，然后趋于缓慢，184 d后基本不变。随腐解时间的延长，N和K的残留量逐渐减少，304 d后基本不变。N在0～46 d和46～92 d的释放率最大，分别达9.3%和9.0%;K的释放集中在0～46 d，释放率达80.4%，以后则变化不大，在90%左右。腐解残留物的C/N先迅速下降，138 d后基本不变，最终为26.3。 |
| 关键词: 荒漠生态 残茬分解 养分释放 |
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| 基金项目:中国科学院阜康荒漠生态系统观测试验站开放基金资助项目(20020009) |
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| The characteristics of decomposition and variation ofnutrient elements of plant residue in desert ecosystem |
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| Abstract: |
| Quantitative studies on changes of decomposition rate,C/N ratio,N,K and organic C of corn residue during decomposition in desert ecosystem were carried out in Fukang,Xinjiang.Results showed that accumulative decay rate and organic C decomposition rate of corn residues increased when the decomposition time was increased.The decay rate in 0-46 d and 46-92 d was 34.6% and 11.9%,respectively.The organic C decomposition rate in 0-46 d and 46-92 d was 34.9% and 12.5%,respectively.The changes of organic C,N and K contents in decay remanent were different.Organic C contents decreased slowly first,then kept on at 184-350 d,then decreased slowly again.The nitrogen contents increased gradually first,then kept on after 138 d.The K contents decreased quickly from 6.53% to 1.92% at 0-46 d,then decreased slowly and kept on after 304 d.The releasing rates of N in 0-46 d and 46-92 d were great,and reached 9.3% and 9.0%,respectively.The releasing rate of K reached 80.4% in 46 d,then changed around 90%.The C/N ratio of decay remanent decreased quickly first,then didn’t change on the whole after 138 d,finally was 26.3. |
| Key words: desert ecosystem residue decomposition nutrient releasing |
