What are the impacts of water deficit, cultivars, and agricultural years on the dynamics of nutrient uptake by common bean? Part I: n, P, and K

Abstract

Knowing the effect of water deficit intensity on the nutrient uptake dynamics by common bean cultivars with contrasting growth habits in different years is necessary to appraise and recommend more specific fertilization management practices. A field study was carried out in the Southeast of Brazil for two years aiming to explain and compare the accumulation and extraction of the macronutrients nitrogen (N), phosphorus (P), and potassium (K) from two common bean cultivars with contrasting growth habits as a function of water deficit severity. The common bean cultivars IAC Imperador and IPR Campos Gerais, with determinate and indeterminate growth habits, respectively, were evaluated. Both cultivars were submitted to three irrigation management practices: severe water deficit (54% of the crop evapotranspiration – ETc), moderate water deficit (77% of ETc), and no water deficit (100% of ETc). Overall, the severe water deficit reduced N, P, and K accumulation in the common bean cultivars by 26, 37, and 23%, respectively. Under no water deficit, IPR Campos Gerais showed higher accumulation of biomass and nutrients N (27%) and P (42%) compared to IAC Imperador, in addition to higher interannual variability in the accumulation of nutrients. The maximum daily demand for nutrients N, P, and K of IAC Imperador was anticipated in 9, 13 and 11 days, respectively, compared to IPR Campos Gerais. Irrigation management, cultivar, and climate of the agricultural year are important factors in decision-making for the most adequate establishment of fertilization with N, P, and K in common bean.