Cultivation Strategies On Yield Formation and Nitrogen Use Efficiency Of Maize.

Low nitrogen (N) use efficiency (NUE) and productivity with excessive use of N fertilizer in grain cereals including maize (Zea mays L.) is a common issue for smallholder farmers. A field experiment was conducted with three integrated agronomic management treatments-MT (OPT-1: an optimized combination of cropping and fertilization system; HY: package of practices based on high-yield studies; OPT-2: further optimized combination of cropping and fertilization system) in comparison with farmers’ practices (FP) for 2 years. Dry matter accumulation, yield, and N utilization parameters were determined.

Our data showed that biomass yields differed significantly with similar harvest index (HI) values among MT treatments. OPT-1 produced 21% greater biomass but only 4% greater grain yield than FP. In comparison, OPT-2 resulted in 44% greater biomass, 27% higher grain yield, and 18% greater PFP_N, respectively, indicating the possibility of achieving high yield and high NUE synchronously.

These results indicate that with optimized agronomic management practices (OPT-2), enhanced grain yield was attributable to the improved total biomass and greater post-silking DM accumulation and N uptake; the enhanced NUE primarily originated from the improved NRE.