Effects of intercropping with Fenlong tillage “145” mode on ratoon sugarcane photosynthesis, growth, and yield

Soil compaction and resource competition are bottlenecks in the improvement of sugarcane productivity in intercropping systems. Fenlong tillage improves crop yields by alleviating soil compaction and ensuring water supply. Wide-narrow rows are an effective solution for light competition. An efficient intercropping system with Fenlong tillage technology as the core needs to be constructed. A two-cycle field study was conducted to investigate the effects of planting methods [sole ratoon sugarcane (S) and ratoon sugarcane-soybean intercropping (I)] combined with tillage [conventional rotary tillage (RT), Fenlong tillage “145” mode (FL145)] on soil physical characteristics, photosynthesis, and growth of ratoon sugarcane, as well as crop yields. For the ratoon sugarcane, compared to RT-I, FL145-I decreased bulk density and increased porosity in the 0–40 cm soil layer. Root growth parameters were improved under FL145-I in the 0–20 cm soil layer. FL145-I positively affected the stomatal conductance, causing increases in the net photosynthetic and transpiration rates. The increased leaf area index, chlorophyll relative content, and photosynthesis under FL145-I caused higher dry matter accumulation. The increased single stalk weight under FL145-I resulted in 17.13%–22.55% higher stalk yield with similar quality. Intercropping under the wide-narrow row planting pattern had no negative effects on the growth and stalk yield of ratoon sugarcane. For the soybean, compared to RT-I, the increased 100-seed weight under FL145-I resulted in 11.14% higher seed yield with similar quality. Therefore, FL145-I presents a promising and novel management practice for sustainably increasing ratoon sugarcane productivity in China.