黄壤小流域水田和旱地土壤养分差异性探析

为探析黄壤小流域不同耕地类型土壤养分特征,选取贵州省黔中地区小流域作为研究区域。采用野外田间土样采集与室内分析相结合的方法,研究黄壤小流域不同类型耕地土壤养分的盈缺、变异程度以及养分间相关性。结果表明:黔中地区黄壤小流域不同类型耕地土壤养分含量相差不大且处于丰富水平,而且不同类型耕地土壤养分变异系数相近,变异程度相当;水田耕地土壤有机质、全氮、碱解氮、有效磷、速效钾为33.90 g/kg、1.30g/kg、116.6 mg/kg、26.69 mg/kg、164.50 mg/kg,旱地耕地土壤有机质、全氮、碱解氮、有效磷、速效钾为31.66g/kg、1.10 g/kg、108.01 mg/kg、29.09 mg/kg、177.75 mg/kg,均处在国家二级、三级水平,黄壤小流域水田和旱地土壤养分变异系数均处在10~100%之间,水田、旱地耕地土壤养分变异系数大小为有效磷速效钾全氮有机质碱解氮p H,其变异程度属于中等变异性。不管在水生环境中还是在旱生条件下,黔中地区黄壤小流域耕地土壤碱解氮、有效磷、速效钾含量较丰富,其差异不明显。水田土壤养分间,除有机质与全氮、全氮与碱解氮有明显的关系外,其他养分之间的关系不明显,其相互影响度不强。旱地土壤养分间关系密切,表现出较强的相关性。此外,不同类型耕地土壤p H值与土壤各养分间的相关性并不一致。

The analysis of soil nutrient differences between paddy field and dry land in Small yellow soil watershed area

To analysize the soil nutrient characteristics of different types of cultivated land, the small yellow soil water-shed area in central Guizhou Province was selected as the study site. Soil samples of different types of cultivated land were collected in the field and analyzed in laboratory. The results showed that the soil nutrient contents from both the paddy fields and dry land had little difference and they all reached the rich level. The variation coefficient of soil nutrients in these two types of soil was similar, and the variation degree was compatible. For the soil samples from paddy field, the contents of soil organic matter were 33. 90 g/kg, total nitrogen 1. 30 g/kg, alkali-hydrolyzable nitrogen 116. 6 mg/kg, phosphorus 26.69 mg/kg and potassium 164.50 mg/kg; while for soil samples from dry land, the contents of the same
counter-part nutrients were 31. 66 g/kg, 1. 10 g/kg, 108. 01 mg/kg, 29. 09 mg/kg and 177. 75 mg/kg, respectively. These contents fall into the national standards of second and third levels. The soil nutrient variation coefficient for both paddy field and dry land were between 10~100%, with phosphorus>potassium>total nitrogen>organic matter>nitrogen>Ph. The variation degree belongs to moderate variability. No matter it is in the aquatic environment or in xeric conditions, the contents of alkali-hydrolyzable nitrogen, phosphorus, potassium were rich in the small yellow soil watershed area of central Guizhou Province and their differences were not obvious. For paddy field, except that there are obvious relation-ships between the organic matter and total nitrogen and between total nitrogen and alkali-hydrolyzable nitrogen, the rela-tionships between other nutrients is not clear and their mutual influence degree is not strong. For dry land, however, the relationships between the different soil nutrients are closely related, showing a strong correlation. In addition, the correla-tion between soil pH value and each of the soil nutrients in the two types of soil is not consistent.