Influence of Crop and Land Management on Wind Erosion from Sandy Soils in Dryland Agriculture

Nikolaus J Kuhn,Heleen C Vos,Frank D Eckardt,Wolfgang Fister,Isabel G Karst

doi:10.3390/agronomy12020457

Nikolaus J Kuhn, Heleen C Vos + Show 3 more

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https://doi.org/10.3390/agronomy12020457

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Abstract

Minimizing wind erosion on agricultural fields is of great interest to farmers. There is a general understanding that vegetation can greatly minimize the wind erosion taking place. However, after harvest, a low vegetation cover can be inevitable, whereby the amount of stubble that remains on a field is dependent on the crop type and land management. This study aims at quantifying the vulnerability to wind erosion of different crops, and the possibility to predict the vulnerability based on high precision aerial images. The study area was the semi-arid Free State, which holds large intensive agriculture on sandy soils. These croplands have been identified as the largest emitter of dust in South Africa. The main crop in the region is maize, but also sunflower, peanut and fallow fields are common land-use types. On these fields, the horizontal sediment flux, the saltation threshold, and aerodynamic roughness length were measured, and the soil cover was assessed using Unmanned Aerial Vehicle (UAV) imagery. The results showed a strong relationship between the soil cover and the sediment flux, whereby fallow and groundnut fields have the highest wind erosion risk. These results emphasize the great importance of soil cover management to prevent wind erosion.

Highlights

Wind erosion is known for the disastrous effects it can have on agricultural lands due to the damage it can bring to the crops by saltation [1,2] and the degrading effect on the soil, because of the removal of nutrients and topsoil [3,4,5,6,7]
Wind erosion is especially a problem in semiarid and arid regions [8], where fields are most vulnerable after harvest, when the soil cover from plants or residue is low
This study aims at quantifying wind erosion on a range of the most common field anemometers, andondust deposition trapsthe and a correlation conditions encountered cropland during dustfound season and at developing betwe an understanding of the land management and croppingdescribed systems that potentially generate the threshold velocity

Summary

Introduction

Wind erosion is known for the disastrous effects it can have on agricultural lands due to the damage it can bring to the crops by saltation [1,2] and the degrading effect on the soil, because of the removal of nutrients and topsoil [3,4,5,6,7]. The dust that is transported from the fields can become part of the global chemical flux and can, have offsite effects on human health and climate. Wind erosion is especially a problem in semiarid and arid regions [8], where fields are most vulnerable after harvest, when the soil cover from plants or residue is low. The total global wind erosion is estimated to be s. 6577 t km–2 yr−1 [9] During these wind erosion processes, roughly 500 to 3320 Tg yr−1 of dust is being emitted [10]. The dust emission from anthropogenic areas has been estimated to be 10% to 25% of the total dust load, whereby the contribution of anthropogenic dust differs greatly per region [8,11]

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