Analysis Main Nutrient Components of Typical Vegetation and Soil in the Yellow River Delta

The Yellow River Delta wetland represents one of the most typical ecosystems in the temperate zone. Influenced by human activities, frequent channel shifts of the Yellow River, and rapid changes in sediment discharge to the sea, the vegetation cover and community structure of the wetland have undergone rapid changes, subsequently affecting soil nutrient components. In order to elucidate the ecological stoichiometry of carbon, nitrogen, and phosphorus in typical vegetation soils of the Yellow River Delta, this study focused on the Dongying City region in Shandong Province. Soil samples (0 to 30 cm) were collected from typical natural vegetation, bare soil, and crops, and the concentrations of organic carbon, total nitrogen, and total phosphorus were determined. The results indicated that: ① Total organic carbon content in soils of different vegetation types followed the order: Glycine max ＞ Zea mays ＞ Gossypium spp. ＞ bare soil ＞ Sorghum bicolor ＞ Suaeda salsa ＞ Spartina alterniflora ＞ Phragmites australis ＞ Tamarix chinensis; Total nitrogen content showed the order: Glycine max ＞ Gossypium spp. ＞ Sorghum bicolor ＞ Spartina alterniflora ＞ Suaeda salsa ＞ bare soil ＞Zea mays ＞ Tamarix chinensis ＞Phragmites australis. ② In the 0 to 10 cm soil layer, the soil ω(C)/ω(N) ratios were in the order: bare soil ＞Phragmites australis ＞ Suaeda salsa ＞ Spartina alterniflora ＞ Tamarix chinensis ＞ Gossypium spp. ＞ Sorghum bicolor ＞ Glycine max ＞Zea mays; ω(N)/ω(P) ratios followed the order: Glycine max ＞Zea mays ＞ Gossypium spp. ＞ Spartina alterniflora ＞ Sorghum bicolor ＞ Suaeda salsa ＞ Tamarix chinensis ＞ bare soil ＞Phragmites australis; ω(C)/ω(P) ratios were in the order: Glycine max ＞ Gossypium spp. ＞Zea mays ＞ bare soil ＞ Spartina alterniflora ＞ Suaeda salsa ＞ Sorghum bicolor ＞Phragmites australis ＞ Tamarix chinensis. ③ Agricultural utilization had an enriching effect on total nitrogen and total phosphorus in the soil. The nutrient content in Glycine max soil was higher than that in the soils of other crops. The organic carbon content in natural vegetation was lower than that in bare soil. Spartina alterniflora and bare soil had double the total nitrogen content in the 20 to 30 cm soil layer compared to other natural vegetation. Different vegetation types had a significant impact on soil nitrogen accumulation, and Spartina alterniflora exhibited an inhibitory effect on nitrogen accumulation in different soil layers. In conclusion, the influence of natural vegetation and crops on soil nutrient components is complex, with natural vegetation consuming more nutrients than accumulating, while crops and agricultural utilization contribute more to nutrient enrichment than depletion.