SOYBEAN AGRONOMIC PERFORMANCE AND SOIL PHYSICAL ATTRIBUTES UNDER TRACTOR TRAFFIC INTENSITIES

ABSTRACT Machinery traffic intensification has been recurrent in intensive agriculture in annual crops, which may lead to structural soil degradation and, consequently, a reduction of its productive capacity. Therefore, this study aimed to assess the influence of tractor traffic intensification on soil physical attributes and soybean yield components. The study was performed in an Oxisol under no-tillage for 10 years, using a randomized block design with five tractor traffic intensities (0, 2, 4, 6, 8, and 12 passes) and five replications. Density, porosity, macroporosity, microporosity, and penetration resistance were assessed in the soil and stem diameter, number of pods per plant, number of grains per pod, grain weight per plant, thousand-grain weight, and grain yield were assessed in the soybean crop. Tractor traffic intensification changed soil physical attributes, which were not limiting factors to soybean yield under the no-tillage system, providing higher stem diameter, number of pods per plant, grain weight per plant, and grain yield after 12 passes.

摘要：一年生作物集约化农业生产中，农机通行强度提升现象频发，可能引发土壤结构性退化，进而降低土壤生产能力。本研究旨在探究农机通行强度提升对土壤物理性状及大豆产量构成要素的影响。本试验在实施免耕达10年的氧化土（Oxisol）上开展，采用随机区组设计，设置5个农机通行强度梯度（0、2、4、6、8、12次通行），共5次重复。试验测定了土壤容重、总孔隙度、大孔隙度、微孔隙度及穿透阻力等土壤物理性状，同时测定了大豆的茎粗、单株荚数、每荚粒数、单株粒重、千粒重及籽粒产量等指标。结果显示，农机通行强度提升会改变土壤物理性状，但在免耕体系下，此类变化并未成为大豆产量的限制因素；当通行次数达12次时，大豆的茎粗、单株荚数、单株粒重及籽粒产量均有所提升。