Effects of combined application of nitrogen and potassium on absorption of N and K,grain yield and quality of weak gluten wheat

The field trials were conducted to study effects of combined application of nitrogen(N) and potassium(K) on nutrient uptake,grain yield and quality of weak gluten wheat on low-K and medium-K soils.The results showed that combination of N and K fertilizers could increase N and K content and absorption of wheat plant.There was a positive interaction of N and K on nutrient absorption.The rational combination of N and K fertilizer increased the yield of weak gluten wheat significantly.The treatment of N180K150 achieved the maximum yield of 5023 kg/ha in low-K soil while the N180K90 obtained maximum yield of 5145 kg/ha in medium-K soil.The yield response of wheat to N was more significant than that of potassium.The significant positive interaction of N and K fertilizer on the grain yield was found in low-K soil.The quality of weak gluten wheat was decreased notably with the increase of N rate in two soils.There was interaction between N and K on quality of weak gluten wheat while the effect of single K was not obvious.The correlation coefficients of N and K content with grain yield or quality were better at jointing and heading stages or at heading and filling stages,respectively.The quality of weak gluten wheat could be improved either by reducing N rate properly or increasing basal N and K ratios.