Effects of Potato Steroidal Glycoalkaloids on Soil Physicochemical Properties, Bacterial Community Diversity and Subsequent Rice Yield

Purpose To investigate the effects of potato steroidal glycoalkaloids (SGAs) from stems and leaves on soil micro-ecology and subsequent rice yield.

Methods Using analyses of soil physicochemical parameters, measurements of yield-determining factors, and Illumina high-throughput sequencing technology, the effects of exogenously added high and low contents of potato SGAs on soil physicochemical properties, bacterial community structure, and the yield of subsequent rice crops were measured.

Results Compared with the control, the addition of SGAs significantly increased soil pH, organic matter content and urease activity, but significantly reduced the relative abundance and diversity of the bacterial community. Analysis at the phylum level revealed that the composition of the top 10 dominant phyla was similar across treatments, but SGAs induced a significant enrichment of the Firmicutes and Bacteroidota phyla. Correlation analysis showed that soil pH and organic matter content were extremely significantly positively correlated with Firmicutes and Myxococcota, whilst being significantly negatively correlated with Proteobacteria. Yield analysis showed that low SGAs content significantly increased rice plant height and the number of grains per panicle, resulting in higher yields; conversely, high SGAs content significantly reduced the number of tillers and the grain-setting rate, leading to lower yields.

Conclusion Although SGAs accumulated in the soil can improve certain physicochemical properties, they inhibit bacterial diversity. Furthermore, it exhibites a clear dose-dependent effect on the yield of the subsequent rice crop, promoting growth at lower content and inhibiting it at higher content.