Fertilizer formulations and planting distances under a sensor-controlled subsurface drip irrigation system in broad bean productivity

Abstract

Increasing food production requires intensive use of arable land and sound water management, the most important determinants of agricultural food production i.e., the irrigation water scarcity, climate change, and the  crops use lack that stimulate and increase soil fertility. Therefore, this study focused on a field crop that improves soil condition and plays a key role in achieving food security. This study evaluated the performance of the Luz-be-otono broad bean variety under different nitrogen-potassium (N+K) fertilizer combinations and planting distances (20,30,40 and 50 cm ). Conducted in a farmer’s field in Al-Muradiyah Research Station (2023-2024 and 2024-2025) using a split-plot RCBD with three replicates, the results demonstrated that the 50 cm planting distance significantly outperformed 20,30,and 40cm across all measured traits: branches number (10.93 and 11.27 branch plant^-1), pods  number in plant (21.37 and 22.80 pod plant^-1), seeds number in pod (4.91 and 5.28 seed pod^-1), 100- seed weight (136.52and 141.64 g), seed yield per plant (65.89 and 67.06 seed plant^-1), protein ratio (23.14 and 23.82%) and carbohydrate ratio (62.81 and 63.55%), seed yield (5.224 and 5.542 t.ha⁻¹),. The N₃K₃ fertilizer combination also surpassed N₀K₀, N₁K₁ and N₂ K₂ in all growth and yield parameters. Optimal results were achieved with the interaction of 50 cm planting distance and N₃K₃ fertilization, highlighting this combination as the most effective for enhancing broad bean productivity under the studied conditions.