| 摘要: |
| 选择干旱区玛纳斯河流域绿洲长期连作棉田土壤为研究对象，研究连作棉田、轮作玉米、轮作大豆、玉米//大豆间作和休闲免耕5种模式对土壤团聚体组成及有机碳分布特征的影响。结果表明：不同种植模式对土壤团聚体有明显的影响，土壤机械稳定性团聚体含量在粒径53～250 μm为最高，占39%～53%，水稳性团聚体含量呈最低； >250 μm机械稳定性团聚体含量在不同种植模式间差异显著，表现为大豆轮作>玉米轮作>休闲免耕>棉花连作>玉米//大豆间作； 秋季作物收获后，轮作大豆和玉米//大豆间作模式土壤团粒指数比春季分别减少18.7%和15.6%； 土壤团聚体有机碳及微生物量碳含量主要集中在>250 μm大团聚体中，而在微团聚体中含量较少； 不同模式土壤有机碳含量顺序为大豆轮作>玉米轮作>棉花连作>休闲免耕>玉米//大豆间作。比较几种种植模式，大豆轮作和玉米轮作有利于团聚体的形成和稳定，可作为长期连作棉田较为理想的短期轮作倒茬模式。 |
| 关键词: 轮作模式 土壤团聚体 有机碳 长期连作 |
| DOI： |
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| 基金项目:高等学校博士学科点专项科研基金（20126518110002）; 国家自然科学基金（31171507）； 国际科技合作专项项目(2011DFA93140) |
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| Effect of planting patterns on organic carbon and soil aggregate composition |
| ZHANG Feng-hua, WANG Jian-jun |
| () |
| Abstract: |
| A field experiment was conducted to investigate the effect of long-term continuous cropping cotton on organic carbon and soil aggregate composition in Manas River oasis. Five patterns were conducted, including continuous cropping cotton, corn rotation, soybean rotation, corn and soybean intercropping and no-tillage. The results showed that the size distribution of soil mechanical aggregate stability was the highest for those between 53 and 250 μm, accounting for 39%～53%, while that of the water-stable aggregates was the lowest. The mechanical aggregate stability size of ＞250 μm showed significant difference among planting patterns, with an order of soybean rotation＞corn rotation＞no-tillage＞continuous cropping cotton＞corn and soybean intercropping. Soil aggregate index of soybean rotation and corn/soybean intercropping decreased by 18.7% and 15.6% in early spring, respectively. The contents of soil aggregate organic carbon and microbial biomass carbon are mainly in the size of >250 μm, being higher than that in microaggregate. The content of soil organic carbon showed an order of soybean rotation＞corn rotation＞continuous cropping＞no-tillage＞corn and soybean intercropping. Compared with rotation patterns, soybeans and corn rotation showed positive effect on stable aggregate formation, which can be used as a reasonable short-term crop rotation patterns. |
| Key words: planting patterns aggregates organic carbon continuous cropping arid land |
