How the Soil Resistance to Penetration Affects the Development of Agricultural Crops?

The SPR is an indicator that describes the physical strength that the soil exerts on the root that tries to move through along the profile, being directly influenced by bulk density, porosity and, mainly, by soil moisture at the time of evaluation. The soil resistance to penetration has been one of the most used parameters in the evaluation of its physical structure. The compaction is one of the problems of greatest relevance in different regions of Brazil, characterized by the alteration of the physical properties of the soil, being the direct result of a particular practice of management in which the soil is subjected to a pressure above its capacity to support, by encouraging the reduction of volume and resulting in increased resistance to penetration and in soil bulk density, impairing root growth and reducing the development of aerial part of the plants. To assist the management of these compacted areas, research has attempted to determine critical levels of soil physical properties for the proper development of the plants, using mainly the SPR. The penetrometer stands as the instrument capable of measuring and provide a good estimate of the soil penetration resistance by becoming an alternative to the survey information with respect to the soil physical quality in order to determine the appropriate management in the context of a sustainable conservation agriculture. In an attempt to resolve the problems arising from the increase of SPR, various alternatives may be used, such as the use of chisel plows and rippers, cover crop, especially species of aggressive root systems with high phytomass production among other management techniques. Knowing the critical limits of RMP is necessary in order to create a soil management plan that is viable and more sustainable for the agricultural system and that favors the growth of plants for productivity gains.