Evaluation of Timing and Rates for Nitrogen Application for Optimizing Maize Growth and Development and Maximizing Yield

Abstract

Core Ideas Nitrogen fertilizer application increased photosynthesic rates during vegetative developmentHigher nitrogen fertilizer application rates are not a sound strategy to obtain maximum grain yieldOptimum timing of nitrogen applications is essential for maximizing yield Accurately applying N fertilizer is challenging for maize (Zea mays L.) farmers in semiarid regions. The goal of this study was, therefore, to identify the best rates and timing of N applications for optimum maize development and maximum grain yield (GY). A 2‐yr study (2009 to 2010) was conducted in the semiarid conditions of Faisalabad, Pakistan. Five N application rates were administered at three different times during each growing season. Photosynthesis, GY, N uptake, and N recovery efficiency (NRE) were significantly affected (P < 0.05) by the rate and timing of N applications. Photosynthesis, GY, and NRE increased linearly following application of 1/3 N at V2, 1/3 N at V16, and 1/3 N at R1 stages (treatment T2) with 250 kg N ha−1. In contrast, the maximum N uptake was observed with an application of 300 kg N ha−1 without a significant increase in GY. The results suggest that N fertilizer recommendations should not be solely based on plant N uptake but also take into account the physiological processes of maize and NRE. Since the optimal N application rate for maximum GY was 250 kg N ha−1, applied in three applications (1/3 N at V2, 1/3 N at V16, and 1/3 N at R1 stages), this rate and timing should be considered as the best fertilizer management practice for semiarid conditions.