基于最小数据集的南方地区冷浸田土壤质量评价

调查分析了我国南方地区7个省份冷浸田土壤理化性状和生物学性状,筛选冷浸田土壤质量评价指标,建立土壤质量评价最小数据集。结果表明:冷浸田土壤有机质、全氮、C/N、有效磷与非冷浸田差异显著,分别较非冷浸田高出26.1%、11.2%、12.3%,低84.6%。冷浸田土壤含水量、有效铁、有效锰、有效锌、Fe~(2+)、Mn~(2+)、还原性物质总量含量分别较非冷浸田显著高出37.6%、91.5%、108.1%、17.0%、349.5%、143.1%、217.9%;冷浸田土壤微生物生物量碳、酸性磷酸酶活性均显著低于非冷浸田,而过氧化氢酶活性显著高于非冷浸田,蔗糖酶活性与非冷浸田相比无显著差异。冷浸田土壤线虫数量为301.9条100 g干土~(-1),显著低于非冷浸田;采用配对样本t检验和主成分分析方法,结果表明冷浸田土壤质量评价的最小数据集为pH、全氮、有效锰、Fe~(2+)、C/N、线虫数量6个指标,冷浸田土壤质量指数显著低于非冷浸田。研究结果对冷浸田土壤质量评价、土壤改良具有重要意义。

Minimum Dataset-based Soil Quality Assessment of Waterlogged Paddy Field in South China

Investigations and analyses were done of the data of soil physical-chemical and biological properties of waterlogged paddy fields in seven provinces of South China in an attempt to screen out indices for soil quality assessment of waterlogged paddy fields and build up a minimum dataset for the assessment. Results show as follows. Waterlogged paddy fields differed sharply from non-waterlogged paddy fields and were 26.1%, 11.2% and 12.3% higher respectively in content of soil organic matter, total nitrogen and C/N, and 84.6% lower in available P. The two types of paddy fields did not varied much in content of soil total phosphorus, available nitrogen and available potassium. Besides, the former was 37.6%, 91.5%, 108.1%, 17.0%, 349.5%, 143.1% and 217.9%, respectively, higher than the latter in content of soil moisture, available iron, available manganese, available zinc, Fe2 , Mn2 , total reducing substance and significantly or 43.8% and 25.2%, respectively, lower in soil microbial biomass carbon and phosphatase activity. However, the former was significantly or 21.2% higher than the latter in soil catalase activity, but did not differ much from the latter in invertase activity. Other than those, the former had a nematode population density of 301.9±78.53 individuals/100g dry soil, which was significantly lower than that in the latter. By means of paired sample T test and principal components analysis, it was found that the minimum dataset (MDS) for soil quality assessment of waterlogged paddy fields should encompass the following six indices, that is, pH, total nitrogen, available manganese, Fe2 , CN ratio and nematode population, which are significantly lower than their corresponding ones for the non-waterlogged paddy fields. All the findings in this study may be of some important significance to soil quality assessment, soil amelioration of cold waterlogged paddy fields.