Rudan Li

Long-term continuous cropping is a prevalent agricultural practice aimed at maximizing land use efficiency and crop yields, yet it often leads to severe soil degradation, nutrient imbalance, and microbial community disruption. Effective soil remediation strategies are urgently needed to restore soil health and ensure sustainable agricultural production. In this study, we investigated the impact of forest soil amendment on microbial community structure, diversity, and functional potential in long-term continuous cropping soils. Using metagenomic sequencing, we analyzed soils from natural forest (BK), forest soil-amended soils (BCP), and fields under continuous cropping for 15 years (CP15) and 30 years (CP30). Forest soil amendment significantly mitigated microbial diversity loss and structural degradation caused by prolonged monoculture. Alpha diversity analysis revealed that BCP restored microbial diversity to levels comparable to BK, while beta diversity and NMDS analyses showed that microbial community composition in BCP closely resembled that of forest soil. Taxonomic profiling indicated that forest soil amendment enriched beneficial taxa such as Actinobacterota and Acidobacteriota, reversing shifts observed in CP15 and CP30. Functionally, COG and KEGG annotations revealed that BCP soils exhibited higher abundances of genes involved in carbohydrate metabolism, energy production, and nutrient cycling. Notably, the amendment reduced antibiotic resistance genes and virulence factors, potentially improving the microbial risk profile of soil communities. These findings demonstrate that forest soil amendment effectively restores microbial community structure and functionality in degraded soils, providing a nature-based solution for sustainable agriculture.

Potassium (K) is a critical macronutrient for sugarcane (Saccharum spp.), playing a vital role in metabolic processes, sucrose accumulation, and yield formation. Herein, this study systematically evaluated the effects of potassium oxide (K₂O) application on sugarcane (cultivar YZ1696) growth at the seedling and tillering stages. Hydroponic experiments demonstrated that 6 mmol/L K₂O optimally promoted seedling growth, whereas field trials revealed that 150 kg/ha K₂O maximized growth rate, yield, and sucrose content. Sugarcane growth exhibited a biphasic response—stimulation followed by inhibition—with increasing K₂O dosage at both developmental stages. Transcriptomic profiling of sugarcane roots under low-potassium (K-deficient), optimal potassium, and high-potassium conditions identified 10,266 differentially expressed genes (DEGs), with the most pronounced transcriptional shifts occurring under K deficiency. Functional enrichment analysis identified DEGs associated with potassium transport, calcium signaling, and carbohydrate metabolism. Notably, potassium uptake was mediated by distinct mechanisms: Shaker family channels (AKT1, AKT2, SPIKE) and the TPK family member KCO1 were induced under optimal K supply, whereas HAK/KUP/KT transporters (HAK1/5/10/21/25) exhibited broad activation across K concentrations, underscoring their key role in K homeostasis. Furthermore, calcium signaling genes (e.g., CIPK23) displayed K-dependent expression patterns. Weighted gene co-expression network analysis identified key gene modules that correlated strongly with agronomic traits, including plant height, yield, and sucrose content. Optimal K conditions favored the expression of yield- and sucrose-associated genes, suggesting a molecular basis for K-mediated productivity enhancement. Our findings revealed the genetic and physiological mechanisms underlying K-dependent sugarcane improvement, providing actionable insights for precise potassium fertilization to maximize the yield and sugar content.

A two-year field study evaluated biodegradable plastic film (BPF; thicknesses: 0.006, 0.008, and 0.010 mm) versus polyethylene film (PE; 0.010 mm) and no-mulch control on sugarcane yield and weed suppression. Key results demonstrated that 0.010 mm BPF significantly enhanced sugarcane emergence (CV = 5.07% in ratoon), reduced weed biomass by 70%, and increased perennial yield by 3.83% (+5.6 t ha⁻¹), while PE film decreased yield by 3.80%. Regression analysis identified the effective stem number, plant height, and stem diameter as primary yield predictors (R² = 0.996). Logistic models revealed that film mulching duration >119 days was critical for achieving high yields (>122.2 t ha⁻¹) and sustained weed control (R² = 0.81). These findings establish 0.010 mm BPF as an optimal sustainable alternative to PE film for enhancing sugarcane productivity.

Ratooning is an important cultivation practice in sugarcane production around the world, with underground buds on the remaining stalk acting as the source for establishment of a subsequent ratoon crop. However, the optimal depth of cutting during harvest in terms of yield and root growth remains unknown. We carried out a two-year field study to determine the effects of three cutting depths (0, 5 and 10 cm below the surface) ratoon cane root and yield. Results showed that cutting to a depth of 5 cm increased the root fresh weight and root volume by 32-40% and 49-85%, respectively, compared to cutting depths of 0 and 10 cm. Remarkably, cutting to a depth of 5 cm also had a significant effect on the development of fine roots, which is closely linked to cane yield. The effect was particularly noticeable in terms of two root traits, root volume and the surface area of roots with a diameter of 1.0-2.0mm, and root length and the number of root tips in roots with a diameter of 0-0.5mm. As a result, a cutting depth of 5 cm below the surface increased cane yield by 35 and 25% compared to depths of 0 and 10 cm below the surface, respectively. Overall, these findings suggest that a cutting depth of 5 cm is optimal in terms of sugarcane yield, largely due to the enhanced effect on root traits, especially the development of fine roots. These findings will help optimize sugarcane ratoon management and improve the ratoon cycle.