农田生态对土壤肥力的保护效应

摘要

Research of long-term fix-experiments showed that in the semi-arid area,the fallow was unfavourable to increase of soil organic matter content.It impelled to drop energy state,increase aromaticity extent and develop forward to aging of humic acid.Fallow made the soil composite aggregate change from G2 to G-1,decrease the activity of soil enzyme,increase the intensity of biochemistry action and decrease the level of total fertility.So,agri-land ecosystem had protective effect of soil fertility.%长期定位试验研究表明，休闲不利于土壤有机质含量的增加，能促使胡敏酸能态降低，分子变大、芳构化程度增大、向“老化”的方向发展；休闲还使G2型复合体向G1型转化，土壤酶活性降低，生化作用强度增大，总体肥力水平下降。因此，农田生态系统对土壤肥力具有保护效应。