Unreasonable fertilization often fails to match crop yield and nutrient requirements, leading to low crop yield, the waste of mineral resources, and increased costs for farmers. A survey of the potato yield and fertilization of farmers was conducted in Haidong City of Qinghai Province for three consecutive years (2017–2019) torecommend reasonable fertilizer application. The results showed that the required amount of NPK fertilizer per ton of potato was 4.85 kg N, 1.26 kg P₂O₅, and 6.98 kg K₂O, respectively. The potato yields ranged from 7500 to 66,429 kg ha⁻¹, with an average of 26,069 kg ha⁻¹. The average N, P, and Kfertilizers (in the form of N, P₂O_5, and K₂O, respectively) applied by the farmers were 213 kg N ha⁻¹, 202 kg P₂O₅ha⁻¹, and 43 kg K₂O ha⁻¹. More than 60% of the farmers appliedtoo much Nand Pfertilizers and too little Kfertilizer. Therefore, the farmers with lowyieldsshould reduce the application of Nand P fertilizers by a range of 41–220 kg ha⁻¹ and 24–265 kg ha⁻¹. Allthe farmers should increase Kfertilizer use by 7–273 kg ha⁻¹. Reasonable fertilization could effectively conserve resources, improve economic efficiency, and reduce environmental impact.

Irrigation-silted soil in Ningxia represents a unique, anthropogenically modified agroecosystem, beneficial for regional food security. Yet, how different agricultural management techniques influence soil microbiome diversity remains poorly explored. Full-length amplicon sequencing (16S rRNA and ITS) was applied to assess the effects of vegetable and maize cultivation, relative to an uncultivated wasteland control, on soil bacterial and fungal community. Cropping patterns significantly influenced microbial alpha diversity, with contrasting effects on bacterial and fungal communities. Specifically, bacterial diversity peaked in vegetable fields, while fungal diversity was highest in maize fields. Both the bacterial and fungal community structures differed markedly among the three land-use types (p < 0.01). Although Pseudomonadota (among bacteria) and Ascomycota (among fungi) were the dominant phyla across all soils, each land-use type harbored distinct biomarkers. For example, vegetable fields facilitated the enrichment of the genus Fusarium, whereas maize fields were characterized by both Pseudomonadota and diverse saprotrophic fungi. Based on functional prediction, sulfur oxidation and cellulose decomposition were enhanced in soil with vegetable cultivation, while maize cultivation promoted relatively broader metabolic activity and enriched arbuscular mycorrhizal fungi compared with the control. Agricultural practices act as selective filters shaping soil microbial assembly and function, which provide a theoretical foundation for sustainable management strategies aimed at preserving soil health.