Resumen
Sugarcane yield in China is low because of the shallow A-horizon soil layer, or as it is commonly called by farmers, the ?plow soil layer?, as well as low soil organic matter and fertilizer utilization efficiency. Fenlong-ridging deep tillage (FT), also called vertical rotary tillage, and amendment with biochar have been shown to improve soil quality and crop yield. In this study, field trials were conducted with newly planted and ratoon sugarcane to evaluate the effectiveness of FT, together with amendment with biochar and nitrogen fertilization, to improve sugarcane yield. The treatments were conventional tillage with chemical fertilizer without biochar (CT-CF, which was the control of this experiment), FT with chemical fertilizer without biochar (FT-CF), conventional tillage with chemical fertilizer mixed with biochar (CT-CFB), and FT with chemical fertilizer mixed with biochar (FT-CFB). FT-CFB treatment presented higher soil porosity, as well as higher contents of available N, P, K, total N, and organic matter, and lower soil bulk density. Similarly, results showed that FT-CFB presented higher sugarcane root fresh and dry weights, higher germination percentage, higher tiller number, and higher yield with statistically significant differences among treatments for both newly planted and ratoon sugarcane plants. Significant interactions between biochar and FT were observed for these crop traits. The interactions of FT and amendment with biochar improved the soil?s physical and chemical properties and increased the available nutrients, resulting in improved root growth and sugarcane yield. The statistical results of the present study imply that Fenlong-ridging deep tillage combined with chemical fertilizer mixed with biochar (FT-CFB) application is a new promising farm management practice for improving the soil?s physical and chemical properties and root growth, increasing total yield in China?s sugarcane belt area.