Reducing sediment concentration and soil loss using organic and inorganic amendments at plot scale

S H R Sadeghi,L Gholami,A Khaledi Darvishan,M Homaee

doi:10.5194/se-6-445-2015

Abstract

Abstract. Various organic and inorganic mulches are used for soil conservation purposes, the effectiveness of which on soil characteristics has not been comprehensively considered from different aspects. The present study surveys the efficiency of straw mulch, manure and TA-200 polyacrylamide with respective rates of 500, 300 and 50 g m−2 in changing sediment concentration and soil loss. The experiments were conducted for sandy-loam soil taken from a summer rangeland, the Alborz Mountains, northern Iran. The experiments were performed under laboratory conditions with simulated rainfall intensities of 30, 50, 70 and 90 mm h−1 and a slope of 30%. The results showed that the straw mulch decreased soil erosion at rate of 45.60% compared to the control plots and performed better than manure (8.98% reduction) and PAM (4.74% reduction). The results showed that the maximum reduction in sediment concentration and soil loss for all soil amendments occurred at the rainfall intensity of 90 mm h−1 with the rates of 58.69 and 63.24% for straw mulch, 14.65 and 13.14% for manure and 20.15 and 23.44% for TA-200.

Highlights

Topsoil erosion is a global problem that causes environmental pollution of waterways and loss of soil fertility (Cerdà et al, 2009a and b, 2013)
Straw mulch as an organic amendment reduces soil erosion and recovers the main soil properties lost due to the agriculture (García-Orenes et al, 2010)
All study treatments could reduce sediment concentration and soil loss at rainfall intensity of 90 mm h−1 more than other intensities. This means that the significant declines in soil loss should be attributed to the organic and inorganic recovery of the plots rather than to variations of the rainfall intensities

Summary

Introduction

Topsoil erosion is a global problem that causes environmental pollution of waterways and loss of soil fertility (Cerdà et al, 2009a and b, 2013). Mulches can increase the infiltration capacity of a soil and strongly control soil erosion (Morgan, 1986), runoff and sediment yield (Poesen and Lavee, 1991; Cerdà, 1998). When the vegetation cover cannot be established, organic and inorganic mulches can be used to protect the soil surface against the erosive forces of rain and runoff (Smets et al, 2008). Previous studies have been conducted about application of soil amendments to improve soil structure (e.g., Karami et al, 2012), change soil and water behavior (e.g., Huang et al, 2014) and reduce postfire runoff and soil erosion in recent years (e.g., Prats et al, 2014). Straw mulch as an organic amendment reduces soil erosion and recovers the main soil properties lost due to the agriculture (García-Orenes et al, 2010). Mannering and Meye (1963) and Adams (1966) showed that the straw mulch could reduce soil erosion in plot scale. Adekalu et al (2007) showed that the sediment yield decreased with the amount of mulch used and increased with slope. Groen and Woods (2008) investigated the role of straw mulch in reducing post-wildfire erosion and showed that the straw mulch ap-

Methods

Results

Discussion

Conclusion