The effect of soil compaction on plant growth is widely used as orientation for soil management. Although the limiting water range (LLWR) underlies the systematization of the relationship between compaction and physical factors directly related to plant growth, its efficiency to predict biological responses, especially of grain yield, has not yet been proven. Results of research at the cellular level indicate that the water and mechanical stress levels that occur in the roots during soil drying are partially represented by the LLWR. Consequently, the expected response in crop growth and production cannot be achieved in most cases. In addition to refining the boundaries of the LLWR, new indexes need to be developed, capable of integrating the variation of the physical factors of soil along the growth cycle of plants determined by meteorological factors. Indicators of frequency of the period of absence and of accumulation of water and mechanical stress were suggested. Without advances, the ability to predict the risk of reduced crop yields due to soil compaction will be marginal and insufficient to support actions of soil management.
no-tillage; least limiting water range; cell elongation
