Accumulation of Nitrogen, Phosphorus, and Potassium in Various Stages of Hybrid Maize (Zea mays L.) as Affected by Different Levels of NPK in Silty Clay Loam Soil of Nepal.

Field experiments were conducted to investigate the effect of various levels of nitrogen, phosphorus, and potassium on the nutrient content of maize grain and stover and their uptake at different growth stages of hybrid maize in silty clay loam soil of Khumaltar, Lalitpur, Nepal, during summer of 2019 and 2020. Experiment was carried out in three factorial randomized complete block design with a total of 27 treatment combinations and replicated 3 times. Three factors were three levels of nitrogen (150, 180, and 210 N kg/ha), phosphorus (40, 60, and 80 P2O5 kg/ha), and potassium (40, 60, and 80 K2O kg/ha). Increasing nitrogen and potassium rates significantly (p <.05) increased total dry matter, grain yield, nutrient concentration, and accumulation of NPK in maize. On average, application of a higher rate of nitrogen (210 kg/ha) and potassium (80 kg/ha) produced grain yields of 10.95 t/ha and 10.54 t/ha, respectively, indicating higher uptake and higher grain yield. The average concentrations of N, P2O5, and K2O were 15.79, 9.56, and 3.77 g/kg in grain and 6.74, 4.17, and 10.46 g/kg in stover at maturity differentiated depending upon the rate of NPK applied. Nitrogen and phosphorus were accumulated mostly in grain (68–83%), whereas potassium was observed more in stover (64–77%). On average, 9.97 tons of maize grain removed 282.81 kg NPK/ha with a positive linear regression (R2) value of 0.89. The reference value of nutrient contents in maize crop obtained from this study can be used to estimate the time and amount of NPK removed from soil for better nutrient management. [ABSTRACT FROM AUTHOR]