长期定位施肥对太湖地区稻麦轮作土壤酶活性的影响

Effects of Long-Term Site-Specific Fertilization on Soil Enzyme Activities of Paddy Fields Under Wheat-Rice Rotation System in Taihu Region

对太湖地区25年长期定位试验田的稻麦两季土壤酶活性进行了测定分析。结果表明,麦季不同施肥处理间的5种土壤酶活性变化没有明显的规律性;无论是仅施化肥还是施有机肥加化肥,稻季5种土壤酶活性的不同肥料配比处理之间绝大多数均无显著差异;成对比较显示,稻麦两季绝大多数相同肥料处理的酶活性之间没有显著差异,仅有稻季猪粪加氮磷钾全施(MNPK)处理的酸性磷酸酶活性极显著高于麦季。分析差异不显著的原因,可能与经过多年的长期定位培肥,土壤储积酶已经达到"饱和"水平,因此不会对外源肥料的施用产生显著响应有关。

The study on soil enzyme activities under wheat-rice rotation system of 25a long-term site-specific experimental fields of paddy soil in Taihu region shows： there was no obvious regularity for the activity variation of five types of soil enzymes under different fertilization treatments in wheat system; there were no significant differences among most soil enzyme activities under different fertilization treatments in rice system. Paired-samples comparison shows that there were no significant differences among most soil enzyme activities under the same fertilization treatments under wheat-rice rotation system, only acid phosphatase activity under rice system of the treatment of NPK fertilizers ＋ stable manure was significant higher than under wheat system. The reasons for no significant differences among most soil enzyme activities might be attributed to the saturation of soil enzymes from accumulation by 25a long-term site-specific fertilization, thus, they won＇t show significant responses to the ectogenic fertilizers.