Potassium nutrition on dry matter and nutrients accumulation and translocation at reproductive stage of maize

Field experiment was conducted to study the effect of potassium (K) nutrition on dry matter and nutrient accumulation and distribution under three K levels (K2O 0, 113 and 225 kg/ha）at reproductive stage of maize to explore the relationship between K nutrition and grain formation in maize. Results indicated that maize yield was significantly increased by K application. Both the maximum and average dry matter accumulation rate was accelerated, and the maximum dry matter accumulation rate occurred early by K application. The distribution proportion of dry matter in different organs varied distinctly. Dry matter, N and P in grain was mainly translocated from spike, and K in grain was mainly translocated from leaves. The contribution percentage of grain nutrient absorption to the whole plant at maturity was 50.3%–57.1%，59.6%–67.2%, and 14.0%–33.3% for N, P and K, respectively. K application could not only increase the distribution proportion of dry matter, N, P, and K nutrition to grain, but also enhance their translocation rates. The maximum N translocation rates of 45.7% was obtained by K1 treatment, while the maximum dry matter, P and K translocation rate of 7.4%, 62.6% and 22.4% was achieved by K2 treatment. 54.5%–60.6% of N, 56.0%–85.8% of P and 52.4%–100.0% of K in grain relied on nutrient translocation from vegetative parts.