Effect of Nitrogen Dose and Application Timing on Nutrient Dynamics and Soil Fertility in Spring Maize (Zea mays L.)

Abstract

Maize requires high nitrogen for optimum yield. However, inappropriate nitrogen dose and timing reduce nutrient content, uptake, and soil health. Hence, evaluate the effect of nitrogen dose and time of nitrogen application on nutrient dynamics and soil fertility in spring maize (Zea mays L.). This field experiment was conducted at Regional Research Station, Uchani, Karnal, of CCS Haryana Agricultural University. The experiment consisted of four nitrogen doses (N1-150, N2-165, N3-180 and N4-195 kg N ha-1) assigned to main plots and four application timing, S1 -50% + 25% + 25 % (sowing+ 8 leaf + tassel initiation), S2 - 25% + 25% + 25% + 25% (sowing+ 4 leaf + 8 leaf + silking), S3 -20% + 30% + 40% + 10% (sowing+ 6 leaf + flowering + grain formation) and S4 - 20% + 30% + 40% + 10% (2 leaf+ 6 leaf +tassel initiation + grain formation) assigned to subplots. The treatments were arranged in a split-plot design with three replications. Results revealed that both nitrogen dose and application timing significantly influenced N, P and K contents in grain and stover as well as their uptake by maize. The highest NPK contents and uptake were recorded with N4 (195 kg N ha-1), which was statistically at par with N3 (180 kg N ha-1) and superior to N2 (165 kg N ha-1) and N1 (150 kg N ha-1). Among the application timing of nitrogen, S4 and S3 (unequal split applications) resulted in higher NPK contents in grain and stover. However, nitrogen uptake by both grain and stover was highest under S2 (four equal splits) followed by S1. The highest phosphorus and potassium uptake was recorded under S4, which was statistically at par with S2. Application of 195 kg N ha-1 recorded the highest residual available nitrogen in soil, which was statistically comparable to 180 kg N ha-1. Available soil phosphorus decreased under higher nitrogen doses (195 and 180 kg N ha-1) compared to lower dose (150 and 165 kg N ha-1). Among application timing, S3 and S4 recorded significantly higher available nitrogen and phosphorus than other treatments.