Conceptual framework for capacity and intensity physical soil properties affected by short and long-term (14 years) continuous no-tillage and controlled traffic

Abstract

Recent studies have shown harmful effects of soil compaction in no-tillage system (NTS), but there are indications that soil structure improves with time of NTS adoption. We formulated the hypothesis that topsoils of NTS initially have worse soil physical conditions than those under conventional systems, but these conditions gradually improve with time also down to deeper depth, even when the soil is wheeled by farm machinery. Our objective was to evaluate the effect of a long-term no-tillage system and machine traffic on soil mechanical and hydraulic properties. The treatments and soil conditions consisted of five periods since the last conventional tillage (or age of NTS) in a Hapludox: 0.2, 1.5, 3.5, 5 and 14 years, with and without traffic; named recent tillage, and initial, intermediate, transition and stabilized NTS phases. Soil samples were collected from soil layers 0-7, 7-14 and 14-21 cm depth to determine soil porosity, precompression stress, compressibility coefficient, saturated hydraulic conductivity, air permeability, water retention curve, bulk density and organic carbon. Conventional tillage of soil previously under notillage significantly affected soil capacity properties, resulting in high macroporosity and deformation susceptibility, low bulk density and precompression stress. Intensity properties were affected initially by an increased soil pore obstruction, negatively affecting air permeability and saturated hydraulic conductivity, from 0 to 21 cm soil depth. However, after five years of no-tillage there was an increase in microporosity and, although small, in soil organic carbon, especially in the 0-7 cm soil layer; thus, soil water retention and soil intensity properties (like soil water and air permeability) were also improved, regardless of farm machinery traffic. Over time, soil reconsolidation occurred, which resulted in reduction of the compressibility coefficient and degree of compactness, mainly in the upper layers (0-7 and 7-14 cm). However, in the deepest layer with the least disturbance, the degree-of-compactness and bulk density increased. The evolution of physical properties and processes (from recent tillage to stabilized NTS phase) for no-tilled soil is proposed for controlled and uncontrolled traffic systems as a framework based on field data for capacity and intensity soil properties. The process of creating aggregates is represented, at first, by an increased number of contact points before they are re-loosened and strengthened at the same time by a rearrangement of particles, reducing aggregate bulk density but increasing soil strength at the same time. The framework is divided into 4 phases: initial (1.5 years), intermediary (3.5 years), transitional (5 years), and stabilized (14 years) conditions. 2015 Elsevier B.V. All rights reserved.

Reclamation of a Degraded Coal-Mining Area with Perennial Cover Crops

“…In this regard, Reichert et al (2016) made a thermodynamic approach to the development of the physical properties of an agricultural system 14 years after adoption of no-till, noting that withdrawal of the disruption caused by soil mobilization under conventional tillage would lead the system to a decrease in entropy production, with changes in the soil structure from initial "anthropogenic" aggregates, prismatic type, to "pedogenic" aggregates, which, ultimately, reaching a state of dynamic equilibrium, would become crumby due to biological action. Similarly, revegetation of the constructed minesoil and growth of its root system, with input of organic matter, restoring flows of matter and energy captured by photosynthesis, would lead the system to a similar situation, with declining entropy production and changes in the state of soil aggregation.…”

“…In addition to reduction of root growth in species, and higher soil BD and lower soil Ma, in general, a higher percentage of macroaggregates is observed in the 0.10-0.20 m layer than in the 0.00-0,10 m soil layer (Table 5). The highest percentage of macroaggregates refers to large, cohesive, and sharp-edged aggregates present in the 0.10-0.20 m layer, whereas aggregates in the 0.00-0.10 m layer were less cohesive and more round-shaped, as perceived by visual observation and manipulation of aggregates during sample preparation, corresponding to "anthropogenic" and "pedogenic" aggregates, respectively, according to Reichert et al (2016).…”

Physical Properties of Soil Structures Identified by the Profil Cultural under Two Soil Management Systems

“…It is known that soil structure plays an important role in water retention, infiltration capacity, soil porosity and resistance to penetration, gas exchange, nutrient uptake, and crop yields (Bingham et al, 2010;Munkholm et al, 2013;Mentges et al, 2016;Reichert et al, 2016). It is important, therefore, to consider that this role of structure becomes increasingly important when there is fair balance between the processes of order and dissipation.…”

“…The cultivated layer is subject to considerable spatial variability, unlike horizons that are not usually affected by tillage (Neves et al, 2003;Fuentes-Llanillo, 2013;Gonçalves et al, 2013;Tavares Filho et al, 2014;Boizard et al, 2016). This variability often allows plants to grow in compacted soils, taking advantage of the flow of water and gas through structural discontinuities (cracks) that also allow root growth (Neves et al, 2003;Reichert et al, 2016). Thus, understanding the dynamics of soil physical properties is improved by using soil properties (such as soil bulk density and porosity) as proposed by Horn and Kutilek (2009).…”

Pine Harvest Impact on Soil Structure of a Dystric Cambisol (Humic)

“…One of the main effects of machinery traffic is the soil compaction process, which causes rearrangement of soil particles . Thus, there are losses to the soil and plants, such as the increase in soil density, penetration resistance, and pore volume of small diameters, and the decrease of total porosity, macropores, gas exchange, infiltration, water percolation, saturated hydraulic conductivity and water availability in the soil for plants (Fernandes and Souza, 2003;Reichert et al, 2003;Silva et al, 2006Silva et al, , 2007bJong van Lier, 2010;Lopes et al, 2011;Reichert et al, 2016).…”