ogen Levels on Root Density, Nutrient Uptake and Grain Yield of August Sown Hybrid Maize (Zea mays L.)

A field experiment was conducted at Punjab Agricultural University Ludhiana, during late Kharif 2009-10 to study the effect of different irrigation regimes (IW/CPE ratio 0.50, 0.75, 1.00 and 1.25) and nitrogen rates (100, 125, 150 and 175 kg N ha^-1) on ischolar_main growth, nutrient uptake and yield of August sown hybrid maize. The irrigation regimes I_1.25 (3 irrigations) and I_1.00 (3 irrigations) produced the grain yield of 83.1 and 81.2 q ha^-1, respectively, which was significantly higher than the grain yield observed under I_0.75 (2 irrigations) and I_0.50 (1 irrigation). Root density was higher in surface soil layers i.e., 0-15 and 15-30 cm soil profile under adequate irrigation regimes (I_1.25 and I_1.00) which was statistically at par with each other but reverse trend was observed in deeper layers where ischolar_main density was higher under deficit irrigation regimes. Nutrient uptake by maize i.e. N, P and K was also higher at higher irrigation regimes. Among nitrogen rates, N₁₅₀ and N₁₇₅ being statistically at par with each other gave significantly higher grain yield over N₁₂₅ and N₁₀₀. Similar trend was observed for ischolar_main density in different soil layers. Total N, P and K uptake was also higher at N₁₇₅ which was significantly higher than other nitrogen levels in case of total N and P uptake whereas it was statistically at par with N₁₅₀ in case of total K uptake.