Relations between soil surface roughness, tortuosity, tillage treatments, rainfall intensity and soil and water losses from a red yellow latosol

Abstract

SUMMARYThe soil surface roughness increases water retention and infiltration, reduces the runoff volume and speed and influences soil losses by water erosion. Similarly to other parameters, soil roughness is affected by the tillage system and rainfall volume. Based on these assumptions, the main purpose of this study was to evaluate the effect of tillage treatments on soil surface roughness (RR) and tortuosity (T) and to investigate the relationship with soil and water losses in a series of simulated rainfall events. The field study was carried out at the experimental station of EMBRAPA Southeastern Cattle Research Center in São Carlos (Fazenda Canchim), in São Paulo State, Brazil. Experimental plots of 33 m² were treated with two tillage practices in three replications, consisting of: untilled (no-tillage) soil (NTS) and conventionally tilled (plowing plus double disking) soil (CTS). Three successive simulated rain tests were applied in 24 h intervals. The three tests consisted of a first rain of 30 mm/h, a second of 30 mm/h and a third rain of 70 mm/h. Immediately after tilling and each rain simulation test, the surface roughness was measured, using a laser profile meter. The tillage treatments induced significant changes in soil surface roughness and tortuosity, demonstrating the importance of the tillage system for the physical surface conditions, favoring water retention and infiltration in the soil. The increase in surface roughness by the tillage treatments was considerably greater than its

Water erosion in surface soil conditions: runoff velocity, concentration and D50 index of sediments in runoff

“…The average value of random roughness (RR) before the application of soil tillage was 4.1 mm, while after chiseling, RR increased to 17.5 mm (Table 1), agreeing with Bramorski et al (2012) who also worked with chiseling under natural rainfall. The lowest RR (9 mm) occurred in BHR, while in HRR and HRV treatments, the values were based on the average of the rainfall tests, 12.3 and 12.1 mm, respectively.…”

Changes in Erosion and Runoff due to Replacement of Pasture Land with Sugarcane Crops

“…An increase in runoff due to crusting and sealing of the soil surface was observed in the field as described in the literature [23,[37][38][39], due to the decreased roughness of the soil [28] and due to sedimentation and break-overs of the contour beds. Sediment was transported along the plots by the concentrated runoff, especially during events with high amounts of rainfall, high intensity, or high frequency, when runoff accumulated along the plot length.…”

“…Most are based on rainfall simulation in small areas [25][26][27], without considering annual variations [28] or using Water Erosion Prediction Project (WEPP) and Universal Soil Loss Equation (USLE) models on watershed scale [29][30][31]. There are even fewer local diagnostics for erosion on grassland, with most estimates made using the USLE model [32,33].…”

Application of Digital Elevation Model (DEM) for description of soil microtopography changes in laboratory experiments

“…The key indicator used to describe the diversity of the soil microtopography is surface roughness (Vidal Vázquez et al 2005). Depending on roughness value there may be delay in the start of surface runoff by storing water in microdepressions, so high roughness is slowing runoff and its volume as well as the loss of soil through erosion (Allmaras et al 1966, Onstad 1984, Hairsine et al 1992, Darboux and Huang 2005, Bramorski et al 2012.…”