---

作 者 ：徐爽 王益权 王浩 祝飞华 冉艳玲 陈静

期 刊 ：植物营养与肥料学报 2012年 18卷 5期 页码：1141-1149

关键词：土壤肥力；团聚体组成；团聚体盐破坏率；团聚体化学稳定性；

Keywords:soil fertility, composition of soil aggregates, percentage of aggregate chemical destruction, chemical stability of soil aggregates,

摘 要 ：在室内利用筛分技术研究了关中地区相同质地类型3个不同肥力水平土团聚体的组成及其稳定性，并在4个不同浓度氯化铵溶液中进行湿筛，探讨了不同肥力土壤团聚体对盐溶液的反应特征及抗化学物质分散的能力，以便揭示长期施用无机氮肥对土壤团聚体的作用与影响。结果表明，干、 湿筛结果显示3个肥力水平土壤直径＞0.25 mm团聚体的含量均随肥力水平的升高显著增加，供试土团聚体的水稳性较差，湿筛后直径＜0.25 mm的微团聚体含量在85%以上，而富有农学价值的直径在15 mm的水稳性团聚体在高肥力土壤中含量仅为2.80%，中肥力土壤为1.47%，低肥力土壤为0.84%。3种肥力土壤团聚体组成受氯化铵溶液浓度的影响，在4种浓度的氯化铵溶液中湿筛后，直径25 mm的团聚体的含量随溶液浓度增大而减少，而0.252 mm团聚体含量明显增加。试验得到的主要结论为，  不同肥力水平土壤团聚体质量差异明显; 团聚体的化学稳定性受盐溶液浓度和肥力水平的共同作用，随氮肥溶液浓度增大，团聚体组成集中在0.252 mm的较小范围，盐分使得多级的团聚体组成向单一化方向变化; 高肥力土壤受氮肥溶液的影响相对较弱，中、 低肥力土壤对氮肥溶液的响应则较为强烈。

Abstract: Chemicals can greatly influence the aggregation of soil stability. The effects of NH4Cl solution on stability of cultivated soil aggregates in Guanzhong area were studied. Soil aggregations were analyzed under dry sieving and sulfurous wet sieving conditions. Soil mean weight diameter, geometric mean weight diameter composition of soil aggregates and percentage of aggregate chemical destruction were calculated. The results indicate that under the dry sieving and wet sieving conditions, the percentages of ＞0.25 mm soil aggregates are significantly increased with the increase of soil fertility, while the waterstability of the tested soil aggregates is low. The percentage of ＜0.25 mm soil aggregates is larger than 85%, while the content of agricultural valuable waterstable aggregates(1-5 mm) is only 2.80% in high fertility soil, 1.47% in middle fertility and 0.84% in low fertility. Concentration of NH₄Cl solution influences composition of soil aggregates, the contents of 2-5 mm soil aggregates are increased with the increase of  NH₄Cl concentration relatively, and the contents of 0.25-2 mm soil aggregates are increased significantly. In conclusion, soil aggregations under different fertility levels are greatly different, and both soil fertility level and concentration of salt solutions can influence chemical stability of soil aggregates. Soil aggregates composition focus to 0.25-2 mm with the increase of concentration of NH₄Cl solution, which results in homogenization of soil aggregates. Relative to the high fertility soil, middle and low fertility soils are affected more severely by the nitrogen fertilizer solution.

---