Effects of Combined Application of Nitrogen and Potassiumon on Yield and Nutrient Accumulation of Wheat in Huaibei Lime Concretion Black Soil Area, China

To provide theoretical and technical basis for the scientific application of nitrogen (N) and potassium (K) fertilizer in wheat cropping in Huaibei lime concretion black soil area, a field experiment was performed to study the effects of different N and K treatments (N:180, 240, 300, 360 kg·hm^-2;K:90, 135, 180 kg·hm^-2) on wheat yields, absorption of N and K, and fertilizer benefits. The results showed that: (1)The wheat yield under application of N₂₄₀K₁₈₀ reached 7 686 kg·hm^-2, which was significantly increased by 7.24% comparing with that under N₁₈₀K₉₀, and there was no significant differences between the yields under N₂₄₀K₁₈₀ and N₃₆₀K₁₈₀; (2)Compared with the contents of N and K in wheat under N₁₈₀K₉₀, those under N₂₄₀K₁₈₀ were significantly increased by 14.67% and 29.53%, respectively; (3)There was a positive interaction between the application of N and K fertilizer, and the interaction was significantly correlated with wheat yield at a contribution rate of 14.06%, which consequently increased the partial productivities of N and K fertilizer. Considering wheat yield and fertilizer benefit, the optimum application amounts of N and K₂O fertilizer were 240 kg·hm^-2和180 kg·hm^-2 in Huaibei lime concretion black soil area