Partial economic assessment of maize grain yield under rainfed conditions using fertilizers of different origins

Maize is the most important feed grain crop worldwide and plays a central role in global food, feed, and industrial production systems. It covers more than а half of the cultivated areas (55%) and nearly three-quarters (72%) of the grain production of all feed crops worldwide. It is a major raw material used for the production of a wide variety of products, mainly concentrated and compound feeds, as well as various food and industrial products such as starch, alcohol, cellulose, paper, construction and insulation materials, among others.Economic analysis of fertilizer use is increasingly recognized as a key component of sustainable agricultural decision-making. This study presents an extended partial economic assessment of grain maize production under non-irrigated conditions, based on real experimental data obtained at the Bozhurishte experimental field in 2023. The analysis was conducted for all experimental variants, as seven fertilization variants were evaluated using grain yield, taking into account the most important indicators characterizing economic efficiency in maize production. The following indicators were analyzed: grain yield (GY), grain revenue (GR), direct production costs (DPC), net income (NI), profitability rate (PR) and benefit–cost ratio (BCR).The results revealed that yield maximization does not coincide with economic optimization. Variants characterized by lower input intensity achieved higher economic efficiency, while excessive fertilization resulted in negative economic outcomes. The findings provide a solid economic basis for optimizing fertilization strategies under rainfed maize production systems.Under conditions of increasing climatic variability, particularly irregular precipitation, economic efficiency becomes a decisive factor in crop management. Rainfed maize production systems are exposed to high yield risk, which amplifies the negative economic consequences of high input intensity. The results of the present study clearly demonstrate that fertilization variants with excessive input costs are economically vulnerable under such conditions.