Legume-potato rotation affects soil physicochemical properties, enzyme activity, and rhizosphere metabolism in continuous potato cropping

Abstract Background Continuous cropping can reduce soil quality and affect rhizosphere metabolism, ultimately reducing crop yield. Crop rotation can mitigate the damage caused by continuous cropping, but different crop rotation patterns respond differently to soil quality and rhizosphere metabolism. We investigated the effects of different cropping patterns on soil physicochemical properties, enzyme activities, microbial quantity, and rhizosphere metabolism of continuous potato cropping based on a long-term field study from 2018 to 2022. The experiment was set up with the following three treatments: potato ( Solanum tuberosum L.)-potato-potato-potato-potato (CK), potato-potato-potato-pea ( Pisum arvense L.)-potato (T1), and potato-potato-potato-faba bean ( Vicia faba L.)-potato (T2). Results The results showed that pea-potato rotation (T1) and faba bean-potato rotation (T2) significantly improved soil physicochemical properties and microbial quantity, enhanced enzyme activity, and increased yield by 21.19% and 28.38%, respectively, compared with the continuous potato crop. Non-targeted metabolomics analysis showed that the differential metabolites of pea-potato and faba bean-potato rotation were mainly nucleotides, organic acids and derivatives, and flavonoids compared to continuous potato cropping. These differential metabolites are mainly enriched in the ABC transporter, purine metabolism, pyrimidine metabolism, and phenylalanine metabolism pathways. Combined analyses showed that legume-potato rotations improved soil physicochemical properties, enzyme activities, and microbial quantity of continuous potato cropping, ultimately increasing tuber yields. In addition, correlation analyses showed that differential metabolites significantly enriched in purine and phenylalanine metabolism ( l -Tyrosine, Trans-Cinnamic acid, Guanine, and Adenine) were also strongly associated with these measurements. Conclusions Therefore, we conclude that legume-potato rotations modulate the abundance and function of rhizosphere metabolites and significantly alter the low molecular metabolite profile of the soil under continuous potato conditions. Some of these important metabolites may play a part in the cycling of nutrients in the soil, making its physicochemical properties and microbial quantity better, raising the activity of soil enzymes, and ultimately increasing the yield of potato tubers. The above results indicate that legume-potato rotation has a positive effect on continuous potato soils. It lays a solid foundation for revealing the complex molecular network and metabolic pathways of microbial communities in soil after legume crop rotation. Graphical Abstract