Aggregate stability as an indicator of soil susceptibility to runoff and erosion; validation at several levels

Abstract

The evaluation of soil susceptibility to runoff and water erosion in the field is often expensive or time-consuming. Several authors have reported that susceptibility is linked to aggregate stability, whose determination is far easier. However, this susceptibility has generally been deduced from rainfall simulation experiments on sieved soil samples, whose behaviour is not always representative of field-scale phenomena. Our aim was to extend the validity of relationships between soil aggregation and erosion through comparisons of topsoil aggregate stability and field-assessed susceptibility to runoff and erosion. Susceptibility to runoff and erosion was determined at several levels, first on a southern French Regosol, through measurements of runoff and soil loss from 1-m 2 microplots under simulated rainfall; second, from 100-to 800-m 2 runoff plots on a Nitosol in Benin, a Ferralsol in Cameroon and a Regosol in Mexico (with additional data on Syria from the literature); and finally, soil susceptibility to erosion was determined through semi-quantitative assessment of the frequency of erosion features on vineyard hillsides in southern France. Aggregate stability was determined by immersion in water and wet-sieving of 2-mm sieved air-dried 0-10 cm soil samples, which actually tests aggregate resistance to slaking. Under simulated rainfall, runoff depth and soil loss after 30 min were negatively correlated with topsoil content in stable macroaggregates (>0.2 mm). On runoff plots, three-year runoff rate and soil loss were negatively correlated with topsoil aggregate stability, especially stable macroaggregate content; these correlations were improved when slope gradient and climate aggressiveness were considered in addition to aggregate stability. On vineyard hillsides, the frequency index of erosion features was negatively correlated with topsoil content in stable macroaggregates, especially in the absence of conservation practices. 2 These results confirm that aggregate stability is a relevant indicator of soil susceptibility to runoff and erosion, especially in Mediterranean and tropical areas where intense rainfall is frequent. They also confirm that simple laboratory determination can provide data closely correlated with those resulting from field investigations.

Changes in physical properties of sandy soil after long-term compost treatment

“…The runoff and water erosion on sandy soil were significantly reduced by the compost application. In earlier studies was reported that the aggregate stability is negatively correlated with erosion and runoff (Barthes and Roose, 2002;Kroulík et al, 2010). Thus, the application of sewage sludge compost improves the structure of sandy soil.…”

Impacts of reforestation approaches on runoff control in the hilly red soil region of Southern China

“…Soil structure was considered as one of the more important indicators of soil erosion (Barthès and Roose, 2002;Amezketa et al, 1996). It is closely related to the movement of water in the soil through physical properties such as water storage capacity, bulk density, and porosity (Truman and Bradford, 1990;Deuchras et al, 1999;Barthès and Roose, 2002).…”

“…It is closely related to the movement of water in the soil through physical properties such as water storage capacity, bulk density, and porosity (Truman and Bradford, 1990;Deuchras et al, 1999;Barthès and Roose, 2002). In addition, organic carbon increases the formation of soil aggregates (Casermeiro et al, 2004).…”

Long‐lasting impact of biowaste‐compost application in agriculture on soil‐quality parameters in three different crop‐rotation systems

“…Besides a substitution of energy and nutrients, and a stimulation of the internal processes in soil governed by the microbial community, the application of biowaste compost in agricultural soils may positively affect soil organic-matter (SOM) content and soil-aggregate stability (Balesdent et al, 2000;Wahlen et al, 2003) and thus may reduce the potential risk of soil erosion (Barthès and Roose, 2002;Leguédois and Le Bissonais, 2004;Cantón et al, 2009). …”