Effects of Different Potassium (K) Fertilizer Rates on Yield Formation and Lodging of Rice

As one of the most important nutrients for plants, potassium (K) has substantial effects on growth and development of crops. Present study was conducted in three different sites in South China in late season in 2019 with theobjective to study the effects of different applied amounts of K fertilizer on yield formation and lodging of rice.Four K fertilizer treatments, K₀: 0 kg potassium oxide (K₂O) ha⁻¹ (control); K₁: 64.20 kg K₂O ha⁻¹; K₂: 128.55 kgK₂O ha⁻¹ and K₃ 153.90 kg K₂O ha⁻¹ were applied in the field experiment. The results showed that K₂ and K₃treatments significantly increased panicle number per unit area, grain number per panicle, seed-setting rate andthe grain yield of rice compared with K₀ treatment. Higher net photosynthetic rates were recorded in K₂ and K₃treatments than K₀ treatment at tillering stage, heading stage and maturity stage. K fertilizer treatments alsoincreased the chlorophyll content and dry matter accumulation by 6.16–23.52% and 21.32–64.59% comparedwith K₀ treatment, respectively. Moreover, the total N and K accumulation in the aboveground tissues of rice significantly increased under K₂ and K₃ treatments compared with K₀ treatment. Furthermore, compared with K₀treatment, K fertilizer treatments significantly enhanced the breaking-resistant strength by 40.94–144.24% andreduced the lodging index of rice by 13.14–36.72%.