quantitative assessment of maize yield gap in shush county using comparative performance and boundary line analysis

Grain maize (zea mays) is a strategic crop with a vital role in global food security. due to a significant yield gap observed in maize farms of khuzestan province, this study aimed to assess the yield gap and identify the key agronomic factors contributing to it in shush county. the research was conducted across 100 maize fields, and data were collected through structured questionnaires and face-to-face interviews. yield performance was evaluated using comparative performance analysis (cpa) and boundary line analysis (bla). the average predicted yield was estimated at 8,685 kg ha⁻¹, whereas the potential yield was estimated at 11,557 kg ha⁻¹, indicating a yield gap of 2,872 kg ha⁻¹. the main factors contributing to this gap included insufficient application of poultry manure (29%), inadequate use of insecticides (18%), sulfur fertilizer deficiency (17%), suboptimal disking frequency (22%), and insufficient irrigation frequency (14%). according to the bla results, optimizing these management variables could substantially improve maize yields. overall, enhancing farm management practices—particularly the efficient use of organic and chemical fertilizers, improved pest control, and proper scheduling of irrigation and tillage operations—can significantly reduce the maize yield gap and increase productivity in the region.