Wind Erosion Losses as Related to Plant Silhouette and Soil Cover

Abstract

Wind erosion adversely affects soils, plants, animals, equipment, the environment, and people. Wind erosion can be minimized or prevented by either standing residue or flat residue cover. Our objective was to develop mathematical relationships between these two crop residue properties and soil loss ratio (SLR: soil loss from protected soil/soil loss from flat, bare soil), for more accurate predictions of wind erosion soil losses. Therefore, from a previously reported wind tunnel study (wind tunnel 1.1 m high, 0.51 m wide, and 5 m long) we took data for velocities ranging from 9.4 to 16.1 m s−1 and silhouette areas (S) of upright wood dowels (simulating plant stems) ranging from 31 to 813 cm2 m−2 of soil surface (washed sand <0.42 mm) and developed the following equation for standing residue and SLRs: SLRs = exp(−28.49 × S0.6413/V2.423) (r2 = 0.95), where S = stalk height (cm) × stalk diameter (cm) × stalk density (no. m−2) and V = wind velocity in m s−1 at a height of 0.61 m. We combined data from a second previously reported wind tunnel (0.9 m high, 0.6 m wide, and 7 m long) study in which the soil had been covered from 0.0 to 80.0% with wood dowels, artificial clods, or cotton (Gossypium hirsutum L.) gin trash with data from field studies published by other researchers for various soil types and soil coverages ranging from 8 to 95% with wheat (Triticum aestivum L.) residue or gravel, and developed the following equation for soil cover and SLRc: SLRc = exp(‐0.04380 × psc) (r2 = 0.94), where psc is the percent of the soil that is covered by nonerodible material (e.g., soil aggregates, rocks, plant material). These equations should be useful to researchers developing and evaluating wind erosion models, prediction systems, and wind erosion control practices.

“Fallow Band System,” a land management practice for controlling desertification and improving crop production in the Sahel, West Africa. 1. Effectiveness in desertification control and soil fertility improvement

“…The former value (74%) is similar to the efficiency of the 5-m-wide fallow vegetation windbreak (70%) described by Banzhaf et al (1992) and higher than the efficiency of surface mulching (46-64%, as mentioned earlier). This higher efficiency, compared with surface mulching, corresponded to the results in Chepil and Woodruff (1963), Siddoway et al (1965), and Bilbro and Fryrear (1994), which showed that the wind erosion controlling efficiency of standing residue was higher than that of flattened one. The trapping efficiency of the fallow band in this study (74% and 58% for annual incoming soil particles and COM, respectively) was lower than that of the 5-m-wide fallow land in Ikazaki et al (2011b,c) (93% and 97%, respectively).…”

Sand and Dust Storms: Impact Mitigation

“…It is successful in reducing erosion and in reducing the loss of water from fields by decreasing evaporation. The relationship between soil loss and vegetation cover (live or dead) is generally exponential: the soil loss ratio is at a maximum of 1 on a bare unprotected surface but decreases rapidly to a value of approximately 0.2 with 40% soil cover [72]. However, work in Sahelian Africa has shown that maintaining a crop residue cover of just 2% on a field reduces the potential wind erosion by at least a factor of three [73].…”

Measurement and data analysis methods for field‐scale wind erosion studies and model validation

“…In most models, non-erodible surface cover includes coarse rock fragments and flat-lying plant residue. Generally, there is an exponential decrease in soil loss with increasing surface cover (Bilbro and Fryrear, 1995). Non-erodible surface cover can be determined using line transects (Laflen et al, 1981) or by counting points touching cover elements on a grid overlaid on a nadir-view photograph of the field.…”