ABSTRACT Dual‐purpose corn cropping is a widespread and economically important agricultural activity in Brazilian rural areas. The objective of this work was to study the structural quality of a dystrophic Red‐Yellow Ultisol under different tillage systems, previous crops and inoculant treatments, and its relationship with corn yield. The long‐term experiment was established in 2001 in the Coastal Tablelands of Northeastern Brazil. A strip‐split plot design was used, testing three tillage systems—conventional tillage (CT), minimum tillage (MT) and no‐tillage (NT)—in combination with four previous crops: sunn hemp ( Sunn hemp juncea L.), pigeon pea ( Cajanus cajan (L.) Millsp.), cowpea ( Vigna unguiculata (L.) Walp.) and pearl millet ( Pennisetum americanum L.), with three replicates. Soil structure was evaluated using the Visual Evaluation of Soil Structure (VESS) method, while corn productivity was assessed by the number and weight of marketable ears. The Vegetation Cover Index (VCI) was visually measured in the field using a standardised apparatus. Each subplot measured 60 m 2 , with 1 m spacing, totaling 83 m in length. The results indicated improved soil conditions under conservation systems, particularly with pigeon pea as a previous crop. Under NT system, structural quality (SQ) values ranged from 1.5 to 3.4. SQ was positively associated with higher VCI values, and the VESS methodology proved effective in classifying corn productivity. These findings demonstrate a direct and positive correlation between soil SQ and vegetation cover in explaining corn yield, highlighting the importance of maintaining physical soil condition as a positive factor for sustaining agricultural productivity after 22 years of continuous tillage.
Pedrotti et al. (Wed,) studied this question.