The impact of standard preparation practice on the runoff and soil
erosion rates under laboratory conditions

Abdulvahed Khaledi Darvishan,Vafa Homayounfar,Seyed Hamidreza Sadeghi

doi:10.5194/se-7-1293-2016

Abstract

Abstract. The use of laboratory methods in soil erosion studies, rainfall simulation experiments, Gerlach troughs, and other measurements such as ring infiltrometer has been recently considered more and more because of many advantages in controlling rainfall properties and high accuracy of sampling and measurements. However, different stages of soil removal, transfer, preparation and placement in laboratory plots cause significant changes in soil structure and, subsequently, the results of runoff, sediment concentration and soil loss. Knowing the rate of changes in sediment concentration and soil loss variables with respect to the soil preparation for laboratory studies is therefore inevitable to generalize the laboratory results to field conditions. However, there has been little attention given to evaluate the effects of soil preparation on sediment variables. The present study was therefore conducted to compare sediment concentration and soil loss in natural and prepared soil. To achieve the study purposes, 18 field 1 ×  1 m plots were adopted in an 18 % gradient slope with sandy–clay–loam soil in the Kojour watershed, northern Iran. A portable rainfall simulator was then used to simulate rainfall events using one or two nozzles of BEX: 3/8 S24W for various rainfall intensities with a constant height of 3 m above the soil surface. Three rainfall intensities of 40, 60 and 80 mm h−1 were simulated on both prepared and natural soil treatments with three replications. The sediment concentration and soil loss at five 3 min intervals after time to runoff were then measured. The results showed the significant increasing effects of soil preparation (p ≤ 0.01) on the average sediment concentration and soil loss. The increasing rates of runoff coefficient, sediment concentration and soil loss due to the study soil preparation method for laboratory soil erosion plots were 179, 183 and 1050 % (2.79, 2.83 and 11.50 times), respectively.

Highlights

Soil, as one of the valuable natural resources, is nonrenewable at short timescales and should be studied with a multidisciplinary perspective (Brevik et al, 2015)
The results of average runoff variables, sediment concentration and soil loss for three replicates of both before and after soil preparation in three studied rainfall intensities are shown in Tables 1 to 3 respectively
The effects of soil preparation practice for laboratory erosion plots on runoff or soil loss were in agreement with previous studies which revealed the same effects of soil preparation for agriculture and gardening purposes

Summary

Introduction

As one of the valuable natural resources, is nonrenewable at short timescales and should be studied with a multidisciplinary perspective (Brevik et al, 2015). The soil system is the key to determining the sustainability of the Earth system. It controls the hydrological, erosional, biological and geochemical cycles and contributes to the resources, goods and services given to the humankind (Keesstra et al, 2016). Study of soil erosion and sediment yield in the watershed is one of the basic necessities to achieve integrated land management and soil and water conservation.

Methods

Results

Conclusion