论文部分内容阅读
对天津不同程度盐渍化农田(n=4)和荒地(n=4)土壤水溶性有机碳(SOC)和水溶性氮素组成与分布特征进行了研究。结果表明:农田和荒地土壤水溶性有机碳(SOC)含量分别为26.1~46.4mg/kg和19.6~77.8mg/kg,由表层向下呈现出降低-升高-稳定的变化趋势。农田土壤具有较高溶解性总氮(TSN)、硝氮(NO-3—N)和水溶性有机氮(SON)含量,分别是荒地土壤的0.8~5.9、0.8~10.5和0.9~8.7倍。NO-3—N和SON是TSN的主要组成部分,分别占农田土壤TSN的38%~72%和26%~60%,荒地土壤的32%~75%和16%~58%。NO-3—N、SON在农田土壤剖面中主要积累在土壤表层和底层,而在荒地土壤剖面中主要积累在土壤表层,且在农田土壤中具有较高的淋溶风险。
The composition and distribution of soil water-soluble organic carbon (SOC) and water-soluble nitrogen in salinized farmlands (n = 4) and wasteland (n = 4) of different degrees in Tianjin were studied. The results showed that the contents of soil organic carbon (SOC) in farmlands and wasteland were 26.1-46.4 mg / kg and 19.6-77.8 mg / kg, respectively, showing a decreasing-increasing-stabilizing trend downward from the surface. The contents of total soluble nitrogen (TSN), nitrate nitrogen (NO-3-N) and soluble organic nitrogen (SON) in farmland soils were 0.8 ~ 5.9, 0.8 ~ 10.5 and 0.9 ~ 8.7 times of the wasteland. NO-3-N and SON are the major components of TSN, accounting for 38% -72% and 26% -60% of cropland soil TSN, 32% -75% and 16% -58% of wasteland soil, respectively. NO-3-N and SON mainly accumulate in the soil surface and bottom in the soil profile of the farmland, but mainly accumulate in the surface layer of the soil in the wasteland soil profile and have a high leaching risk in the farmland soil.