水肥一体化减量施肥对坡地烤烟肥料利用率及土壤养分平衡的影响.

[Objective] The present paper aimed to explore suitable water and fertilizer integration with reduced fertilization mode for flue-cured tobacco production on slope land in southern tobacco-growing areas [Method] Taking the local conventional water and fertilizer management as a comparison, the effects of water and fertilizer integration on dry matter accumulation, N and K absorption and distribution, fertilizer utilization rate and soil nutrient balance of Hue-cured tobacco on slope land were studied. [ Result] Results of two-year experiment showed that the dry matter accumulation, nitrogen and potassium absorption of flue-cured tobacco with water and fertilizer integrated management were still higher than those of control when fertifu.er was reduced, and fertilizer utilization ratio significantly increased, and the nutrient surplus and balance coefficient were reduced. T2 treatment with 20 % reduced fertilization increased the dry matter accumulation by 22. 28 % in maturing stage than that of conventional treatment, and promoted the absorption of nitrogen and potassium by 92. 64 % and 83. 23 % respectively in root extending stage. The apparent utilization rate, season recycling rate and economic utilization rate of nitrogen fertilizer of T2 treatment increased by 20. 98 %, 14. 6 % and 8. 6 % respectively compared with CK, even 15. 25 %, 16. 15 % and 17. 64 % higher than Tl treatment with the same amount fertilizer. Fertilizer productive efficiency of potassium increased by 35. 02 % on average, and the biggest difference of apparent utilization rate, season recycling rate and economic utilization rate between T2 and CK appeared in 2017, reaching 80. 62 %, 105. 6 % and 126. 03 % . From the soil nutrient balance, water and fertilizer- integration mode increased crop carrying capacity and reduced nutrient surplus. Compared with CK, T2 and T3 treatments reduced nitrogen surplus by 49. 3 and 54. 6 kg • hm -2, and the nutrient balance rate decreased 93. 85 and 103. 16 percentage points. The best performance on potassium balance was T2 treatment, it's potassium surplus decreased by 86. 69 kg·hm-2 compared with CK, and the balance rate fell 158. 75 percentage points. [ Conclusion] In conclusion, under the water and fertilizer integration mode, it can improve the fertilizer utilization rate and reduce the soil nutrient surplus by properly reducing the fertilizer consumption and increasing the topdressing ratio. [ABSTRACT FROM AUTHOR]