苏北沿海地区不同盐渍化土壤养分及生物学特性

Nutrient and biological characteristics of different salinized soils in coastal areas of northern Jiangsu Province

为了研究土壤发育过程中形成的不同程度盐渍化土壤特性,以苏北大丰港为研究对象,探讨不同盐渍化程度下土壤养分及生物学特性的变化特征。研究表明:(1)近海口处多为盐土与重度盐渍化土壤,无植被生长;2~4km处以中度盐渍化土壤为主,植被类型为碱蓬(Suaedasalsa)、盐蒿(Artemisiahalodendron)、灰绿灰藜(Chenopodium glaucum Linn.);大于4 km处为轻度盐渍化土壤和非盐土,以芦苇(Phragmites australis)、茵陈蒿(Artemisia halodendron)、马齿苋(Portulaca oleracea Linn.)和大豆(Glycine max Linn)。(2)滨海盐土受海水影响,土壤有机质、全氮速效磷、速效钾含量高于其他盐渍化土壤和非盐土。(3)土壤全磷、全钾含量受盐分影响较小,全磷含量为1.09~1.51 g·kg-1,全钾含量为8.4~9.6 g·kg-1。(4)不同盐渍化土壤微生物生物量碳含量差异不显著。(5)随盐渍化程度降低,微生物熵呈上升趋势,但在轻度、中度、重度盐渍化土壤中反应不明显。(6)盐分抑制土壤脲酶、蔗糖酶、过氧化物酶活性,碱性磷酸酶活性在中度盐渍化土壤达到最低。综合以上,盐渍化程度不同,土壤养分、微生物生物量、酶活性的变化趋势不同。去除海水对盐土的影响,盐分对不同盐渍化土壤特性的影响主要体现为抑制作用。相较于微生物生物量碳,微生物熵更能反应微生物量的变化。

The soil forms different degrees of salinized soil during development, in order to study the characteristics of different degrees of salinized soil. Dafeng Port in northern Jiangsu Province was selected as the research object, the purpose was to investigate the changes of soil nutrient and biological characteristics under different salinization degrees. The results showed that(1) Most of the offshore estuary is saline soil and heavy saline soil, no vegetation can grow;moderately salinized soil is 2-4 km away from the sea, and the vegetation types are Suaeda salsa and Artemisia halodendron, Chenopodium glaucum Linn;lightly salinized soil and non-salt soil is 4 km away from the sea, there are Phragmites australis, Artemisia halodendron, Portulaca oleracea Linn and Glycine max Linn.(2) The coastal saline soil is affected by seawater, soil organic matter, total nitrogen available phosphorus and available potassium are higher than other salinized soils and non-salt soils.(3) The content of total phosphorus and total potassium in soil was less affected by salt, the total phosphorus content was 1.09-1.51 g·kg-1, and the total potassium content was 8.4-9.6 g·kg-1.(4) The difference of microbial biomass carbon content in different salinized soils was not significant.(5) With the decrease of salinization degree, the microbial entropy showed an upward trend, but the reaction was not obvious in mild, moderate and severe salinized soil.(6) Salt inhibited soil urease, sucrase and peroxidase activities, and alkaline phosphatase activity reached the lowest in moderately salinized soil. In general, the degree of salinization is different, and the trends of soil nutrient, microbial biomass and enzyme activity are different. Salt has an inhibitory effect on soil properties, removing the saline soil which is influenced by sea water. Microbial entropy is more responsive to changes in microbial biomass than microbial biomass carbon.