Optimizing nitrogen fertilizer and planting density levels for maize production under current climate conditions in Northwest Ethiopian midlands

Abstract

This study determined the most effective plating density (PD) and nitrogen (N) fertilizer rate for well-adapted BH540 medium-maturing maize cultivars for current climate condition in north west Ethiopia midlands. The Decision Support System for Agrotechnology Transfer (DSSAT)-Crop Environment Resource Synthesis (CERES)-Maize model has been utilized to determine the appropriate PD and N-fertilizer rate. An experimental study of PD (55,555, 62500, and 76,900 plants ha⁻¹) and N (138, 207, and 276 kg N ha⁻¹) levels was conducted for 3 years at 4 distinct sites. The DSSAT-CERES-Maize model was calibrated using climate data from 1987 to 2018, physicochemical soil profiling data (wilting point, field capacity, saturation, saturated hydraulic conductivity, root growth factor, bulk density, soil texture, organic carbon, total nitrogen; and soil pH), and agronomic management data from the experiment. After calibration, the DSSAT-CERES-Maize model was able to simulate the phenology and growth parameters of maize in the evaluation data set. The results from analysis of variance revealed that the maximum observed and simulated grain yield, biomass, and leaf area index were recorded from 276 kg N ha⁻¹ and 76,900 plants ha⁻¹ for the BH540 maize variety under the current climate condition. The application of 76,900 plants ha⁻¹ combined with 276 kg N ha⁻¹ significantly increased observed and simulated yield by 25% and 15%, respectively, compared with recommendation. Finally, future research on different N and PD levels in various agroecological zones with different varieties of mature maize types could be conducted for the current and future climate periods.

Keywords:

• maize model
• planting density
• nitrogen fertilizer
• yield
• Northwest Ethiopia midland

PUBLIC INTEREST STATEMENT

Maize is the most essential food security cereal crop in the world, followed by wheat and rice. It accounts about 60% of global human consumption, livestock feed and raw materials for industrial purposes. Maize has profound effects on the livelihoods of millions of people in sub-Saharan Africa (SSA). It can be widely grown crop in various agroecological zones and seasons throughout all of Ethiopia’s peripheries. However, the average maize productivity is very low as compared to the global average due to climate condition and inappropriate agronomic management practices. The optimum planting density and nitrogen fertilizer levels can significantly improve the yield of maize. For this reason, planting density and nitrogen fertilizer levels for the current climate period have been optimized by help of decision support tools. Therefore, farmers have to be motivated to adopt these findings with strong confidence to increase maize productivity on the Northwest Ethiopian midlands and similar agroecological zones.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data used to support the findings of this study are included in the results part of the manuscript

Additional information

Notes on contributors

Abebe Zeleke

Abebe Zeleke (PhD candidate) is PhD candidate in University of Gondar, College of Agriculture and Environmental Sciences, Gondar, Ethiopia, and he was employed by Debre Tabor University, College of Agriculture and Environmental Sciences, and serving as a full-time lecture in plant sciences and researcher. His key areas of interest are agronomy and climate change, soil fertility and crop modeling.