Erosão em entressulcos em diferentes preparos e estados de consolidação do solo

Schäfer, Marcos José; Reichert, José Miguel; Reinert, Dalvan José; Cassol, Elemar Antonino

doi:10.1590/s0100-06832001000200019

Cited by 21 publications

(18 citation statements)

References 30 publications

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“…The higher erosion resistance of a soil surface under cultivation, compared to no cultivation, is due to the combined effects of machinery traffic, plant root pressure, soil drying due to soil-water extraction by plant roots, and microbial activity, all of which contribute to a more consolidated soil surface Schafer (Figure 2) and bulk density (Figure 3) for the reconsolidating soil with cultivation, compared to the one without cultivation. For non-cultivated soils, reconsolidation occurs exclusively by gravity, wetting-drying processes, and direct raindrop impact (Allison, 1968;Tisdall & Oades, 1982;Oades, 1984), while for cultivated soils there are the additional, important effects of machinery and plant root pressures, as well as the effect of soil drying due to soil-water extraction by plant roots, all of which contribute to the reconsolidation process of the soil surface.…”

Section: Soil Lossesmentioning

confidence: 99%

Reconsolidation of the soil surface after tillage discontinuity, with and without cultivation, related to erosion and its prediction with RUSLE

Streck¹,

Cogo

2003

Rev. Bras. Ciênc. Solo

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Site-specific regression coefficient values are essential for erosion prediction with empirical models. With the objective to investigate the surface-soilconsolidation factor, Cf, linked to the RUSLE's prior-land-use subfactor, PLU, an erosion experiment using simulated rainfall on a 0.075 m m-1 slope, sandy loam Paleudult soil, was conducted at the Agriculture Experimental Station of the Federal University of Rio Grande do Sul (EEA/UFRGS), in Eldorado do Sul, State of Rio Grande do Sul, Brazil. Firstly, a row-cropped area was excluded from cultivation (March 1995), the existing crop residue removed from the field, and the soil kept clean-tilled the rest of the year (to get a degraded soil condition for the intended purpose of this research). The soil was then conventional-tilled for the last time (except for a standard plot which was kept continuously cleantilled for comparison purposes), in January 1996, and the following treatments were established and evaluated for soil reconsolidation and soil erosion until May 1998, on duplicated 3.5 x 11.0 m erosion plots: (a) fresh-tilled soil, continuously in clean-tilled fallow (unit plot); (b) reconsolidating soil without cultivation; and (c) reconsolidating soil with cultivation (a crop sequence of three corn- and two black oats cycles, continuously in no-till, removing the crop residues after each harvest for rainfall application and redistributing them on the site after that). Simulated rainfall was applied with a Swanson's type, rotating-boom rainfall simulator, at 63.5 mm h-1 intensity and 90 min duration, six times during the two-and-half years of experimental period (at the beginning of the study and after each crop harvest, with the soil in the unit plot being retilled before each rainfall test). The soil-surface-consolidation factor, Cf, was calculated by dividing soil loss values from the reconsolidating soil treatments by the average value from the fresh-tilled soil treatment (unit plot). Non-linear regression was used to fit the Cf = e b.t model through the calculated Cf-data, where t is time in days since last tillage. Values for b were -0.0020 for the reconsolidating soil without cultivation and -0.0031 for the one with cultivation, yielding Cf-values equal to 0.16 and 0.06, respectively, after two-and-half years of tillage discontinuation, compared to 1.0 for fresh-tilled soil. These estimated Cf-values correspond, respectively, to soil loss reductions of 84 and 94 %, in relation to soil loss from the fresh-tilled soil, showing that the soil surface reconsolidated intenser with cultivation than without it. Two distinct treatmentinherent soil surface conditions probably influenced the rapid decay-rate of Cf values in this study, but, as a matter of a fact, they were part of the real environmental field conditions. Cf-factor curves presented in this paper are therefore useful for predicting erosion with RUSLE, but their application is restricted to situations where both soil type and particular soil surface condition are similar to the ones investigate in this study.

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Section: Soil Lossesmentioning

confidence: 99%

Reconsolidation of the soil surface after tillage discontinuity, with and without cultivation, related to erosion and its prediction with RUSLE

Streck¹,

Cogo

2003

Rev. Bras. Ciênc. Solo

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“…When soil compaction occurs at the surface, it represents a severe limitation to soil water infiltration, which will lead to erosion, even under no-tillage, where the presence of straw mulch favors water infiltration (Schäfer et al, 2001;Cassol & Lima, 2003). Soil pores, responsible for retaining water in water field capacity, may be reduced even by light one-dimensional pressures, (Bortoluzzi et al, 2008), which has a negative effect on soil water dynamics and crop yield .…”

Section: Introductionmentioning

confidence: 99%

Soil water dynamics related to the degree of compaction of two brazilian oxisols under no-tillage

Silva

Reichert

Reinert

et al. 2009

Rev. Bras. Ciênc. Solo

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SUMMARYSoil water properties are related to crop growth and environmental aspects and are influenced by the degree of soil compaction. The objective of this study was to determine the water infiltration and hydraulic conductivity of saturated soil under field conditions in terms of the compaction degree of two Oxisols under a no-tillage (NT). Two commercial fields were studied in the state of Rio Grande do Sul, Brazil: one a Haplortox after 14 years under NT; the other a Hapludox after seven years under NT. Maps (50 x 30 m) of the levels of mechanical penetration resistance (PR) were drawn based on the kriging method, differentiating three compaction degrees (CD): high, intermediate and low. In each CD area, the infiltration rate (initial and steady-state) and cumulative water infiltration were measured using concentric rings, with six replications, and the saturated hydraulic conductivity (K (θ θ θ θ θs) ) was determined using the Guelph permeameter. Statistical evaluation was performed based on a randomized design, using the least significant difference (LSD) test and regression analysis. The steady-state infiltration rate was not influenced by the compaction degree, with mean values of 3 and 0.39 cm h -1 in the Haplortox and the Hapludox, respectively. In the Haplortox, saturated soil hydraulic conductivity was 26.76 cm h -1 at a low CD and 9.18 cm h -1 at a high CD, whereas in the Hapludox, this value was 5.16 cm h -1 and 1.19 cm h -1 for the low and high CD, respectively. The compaction degree did not affect the initial and steady-state water infiltration rate, nor the cumulative water infiltration for either soil type, although the values were higher for the Haplortox than the Hapludox.Index terms: water infiltration, mechanical penetration resistance, kriging, porosity.(

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“…As amostras coletadas em baldes no final de cada chuva foram peneiradas em água para medir o tamanho de sedimentos erodidos pelos parâmetros diâmetro médio geométrico (DMG) e diâmetro mediano (D 50 ), conforme procedimentos descritos em Schäfer et al (2001). (King, 1992), que é o fator de correção atribuído à diminuição da velocidade com a profundidade do escoamento decorrente do atrito com o solo.…”

Section: Determinações E Cálculos De Parâmetros De Erosãounclassified

“…Comparando somente os solos preparados convencionalmente, o DMG e o D 50 foram menores no CR que no CC, no qual a consolidação aumentou a estabilidade de agregados do solo (Schäfer et al, 2001), aumentando a sua resistência ao impacto das gotas da chuva.…”

Section: Chuva Simuladaunclassified