Optimal cultivation measures for maize production in the drylands of the Loess Plateau

Proper nutrient management and planting density can effectively improve crop yields and economic efficiency. Optimized fertilization and high-density planting measures have gained attention for their ability to balance high crop yields with efficient nitrogen utilization. High and stable yield of maize is an important guarantee for global food security, and fertilizer and planting density are important factors affecting yield components. In this study, dryland maize (Zea mays L.) in the Loess Plateau was used as the research material, and a three-factor, five-level quadratic orthogonal rotated combination design with organic fertilizer, nitrogen fertilizer and density were set up for a field trial. Regression models of organic fertilizer, nitrogen fertilizer, density and maize yield were established. The results showed that the contribution of each factor to maize yield was in the order of density > nitrogen fertilizer > organic fertilizer. The contribution rates are as follows: 90.02, 89.23, and 79.66, respectively. The univariate analysis concluded that maize yield increased with increasing application of organic fertilizer. Nitrogen fertilizer and density positively affected maize yield within a certain range. Maximum yield is achieved when nitrogen fertilizer and planting density are set at levels 150 kg hm^-2 and 82,500 plants hm^-2, respectively. The analysis of the intercropping effects showed that organic fertilizer-nitrogen fertilizer, organic fertilizer-density, and nitrogen fertilizer-density intercropping had a synergistic effect on maize yield. Optimisation analysis of different cultivation measures was used to obtain the optimum range of treatments for yields higher than 15,000 kg hm^-2: 6,429.30-7,895.10 kg hm^-2 for organic fertilizer application, 159.30-203.55 kg hm^-2 for nitrogen fertilizer application, and 72,465-80,940 plants hm^-2 for planting density. This study explored the effects of different ratios and interactions of organic fertilizer, nitrogen fertilizer and density on maize yields, and screened out the scientific level of dense fertilizer to provide theoretical basis and practical experience for the standardised cultivation of maize in the Loess Plateau.