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 the objective to study the effects of different applied amounts of K fertilizer on yield formation and lodging of rice. Four K fertilizer treatments, K-0: 0 kg potassium oxide (K2O) ha(-1) (control); K-1: 64.20 kg K2O ha(-1); K-2: 128.55 kg K2O ha(-1) and K-3 153.90 kg K2O ha(-1) were applied in the field experiment. The results showed that K-2 and K-3 treatments significantly increased panicle number per unit area, grain number per panicle, seed-setting rate and the grain yield of rice compared with K-0 treatment. Higher net photosynthetic rates were recorded in K-2 and K-3 treatments than K-0 treatment at tillering stage, heading stage and maturity stage. K fertilizer treatments also increased the chlorophyll content and dry matter accumulation by 6.16-23.52% and 21.32-64.59% compared with K-0 treatment, respectively. Moreover, the total N and K accumulation in the aboveground tissues of rice significantly increased under K-2 and K-3 treatments compared with K-0 treatment. Furthermore, compared with K-0 treatment, K fertilizer treatments significantly enhanced the breaking-resistant strength by 40.94-144.24% and reduced the lodging index of rice by 13.14-36.72%.

Automated summary

Potassium fertilizer treatments significantly improve rice yield formation, chlorophyll content, dry matter accumulation, total N and K accumulation in aboveground tissues, breaking-resistant strength, and reduce lodging index.