The effect of mineral fertilizer rates on plant height of grain legumes grown as a repeat crop

Abstract

The article examines the effect of six mineral fertilizer rates on plant height in soybean cv. Selekta-302, mung bean cv. Navro'z and common bean cv. Qizil don grown as a repeat crop on meadow-saz alluvial soils of Uzbekistani district, Fergana region, in 2022-2024. Plant height responded to the nitrogen rate linearly: at maturity y = 79.88 + 0.3789x (R² = 0.988) for soybean, y = 56.50 + 0.1900x (R² = 0.938) for mung bean, and y = 59.26 + 0.2120x (R² = 0.988) for common bean. At N120P90K40 plant height increased by 25.1-36.9% compared with N30P90K40, yet nitrogen use efficiency declined 1.7-4.2-fold beyond N90P90K40.