Critical limits of soil physical attributes for corn and black oat in a Xanthic Hapludox

Soil compaction can decrease potential crop yield and is frequently found in no-till cultivation systems, but there islittle information on the critical limits of soil physical properties these conditions, especially subtropical soils. The objectives ofthis study were to evaluate infl uence tractor traffi c identifi es bulk density,soil degree, macro, microporosity corn black oat assessed situ a Xanthic Hapludox inSouthern Brazil. Tractor machine (0, 2, 5 20 passes) was established create different levels.Undisturbed samples collected at depths 0.00-0.05, 0.07-0.12 0.17-0.22 m just after two moments:before cultivation, then before cultivation. Under conditions this experiment, 10% higher yields cornand oats obtained with macroporosity above 0.10 m3 m-3 0.13 m3m-3, respectively. Similarly, compactnessdegrees 90% 86% considered for oat, In addition, by machinetraffi reduced maize up 33% biomass 44%. Our results demonstrate that growers should be awareof consequences properties, as it severely compromise yields, oatscultivated very clayey like one evaluated study.