Smart bio-mineral integration to enhance sorghum productivity in gypsiferous soils

This study aimed to evaluate the effects of bacterial biofertilizers (Azotobacter and Bacillus) integrated with phosphate mineral fertilizer (DAP), while keeping nitrogen fertilizer (urea) constant across all treatments, on the growth and yield of sorghum (Sorghum bicolor L.) cultivated in gypsiferous soils in Iraq. This study was conducted in 2025 in a gypsiferous soil region of Iraq, where nutrient limitations particularly nitrogen and phosphorus reduce sorghum productivity. The site conditions reflect the broader challenges facing cereal cultivation in degraded soils. Therefore, the experiment provided a realistic platform to assess the effectiveness of integrating biofertilizers with mineral fertilizers in improving crop performance under such conditions. The field experiment was conducted in a randomized complete block design (RCBD) with ten treatments and three replications. Measurements included plant height, leaf number, chlorophyll content, days to 50 % flowering, 1000-grain weight, grain number per head, grain yield per plant and grain yield per hectare. Results showed that the treatment combining compost with biofertilizer achieved the highest plant height (295.3 cm), chlorophyll content (57.3 SPAD) and grain yield (5.69 t ha-1). It also recorded superior yield components, including the greatest 1000-grain weight and seed number per head, reflecting a marked improvement in both vegetative vigour and reproductive efficiency. The findings suggest that the integration of mineral fertilizer and bacterial inoculants is an effective strategy to improve sorghum productivity in gypsiferous soils, addressing a research gap given the scarcity of such studies under Iraqi conditions.