Chlorophyll content and grain yield of common bean as affected by nitrogen fertilization

Abstract

Nitrogen fertilizer recommendations for common bean crop regard conventional tillage, which may underestimate the crop necessity in no-tillage system, because greater demand for nitrogen can occur in this system. The objective of this work was to evaluate the performance of common bean (Phaseolus vulgaris L.) affected by different nitrogen levels on two management soil systems, as well as to verify the possibility on the use of chlorophyll content as an indicative of N content in leaves. A randomized complete block design, in splitplot scheme with four replications, was used. The plots were constituted by management soil systems: no-tillage and conventional tillage (one disk harrow + two levelling harrow). Five N levels (0, 35, 70, 140, and 210 kg ha^-1, as urea) sidedressing fertilization constituted the subplots. Common bean crop grown in no-tillage system demanded more N than in conventional tillage system. No-tillage system provided greater sidedressing N use efficiency by common bean crop, causing greater yield by each nutrient unit applied than the conventional tillage system. The indirect measurement of chlorophyll content was feasible for indicating the common bean N nutritional status, in both management soil systems.