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在小麦生长季节对太湖地区典型土壤乌栅土中NO3--N、NH4+-N和速效磷的动态变化进行研究。结果表明:土壤中NO3--N含量在不同生长阶段差异较大,小麦播种后NO3--N含量最低,然后开始逐渐积累,在小麦灌浆成熟阶段含量最高;NH4+-N含量与NO3--N表现出类似的趋势;速效磷含量在不同阶段差异很小。在土壤剖面中NO3--N从土壤表层到底层迅速下降,表层NO3--N的含量是底层NO3--N含量的数倍,NH4+-N含量从上层到下层逐渐递减;速效磷从表层到底层呈逐渐下降的趋势,各个层次土壤中的速效磷含量变化很小;由于降雨比历史同期偏少,土质黏重,NO3--N的淋失减少,NH4+-N和土壤溶液中速效磷容易被吸附固定,所以土壤养分运移对研究区地下水影响较小。小麦生长季节,由于土体裂隙较多,导致土壤中养分含量与饱和导水率关系不明确;养分含量与黏粒呈显著的线性负相关;与有机质呈显著的线性正相关在一定程度上用有机质含量表征土壤中有效养分对生态环境的影响是可行的。
The dynamic changes of NO3 - N, NH4 + -N and available phosphorus in the typical soil in the Taihu Lake region during the wheat growing season were studied. The results showed that the content of NO3 - N in soil varied greatly at different growth stages. The content of NO3 - N in the wheat after planting was the lowest, and then began to accumulate gradually. The content of NH4 + -N was the highest in NO3 - N Showing a similar trend; available phosphorus content in different stages of small differences. In the soil profile, NO3 - N decreased rapidly from the surface to the bottom of the soil. The content of NO3 - N in the surface layer was several times that of the NO3 - N in the bottom layer, and the content of NH4 + -N gradually decreased from the upper layer to the lower layer. The content of available phosphorus in the soil changed little at all levels. Because the precipitation was less than the same period of history, the leaching of NO3 - N decreased, and the content of available phosphorus in soil solution was easy to be NH4 + -N Is adsorbed and fixed, so soil nutrient transport has little impact on groundwater in the study area. The relationship between soil nutrient content and saturated hydraulic conductivity was not clear due to more soil fissures during the growing season. Nutrient content was significantly negatively correlated with clay particle. Significant linear positive correlation with soil organic matter was observed to some extent It is feasible to characterize the effect of organic matter in the soil on the ecological environment.