Role of selected riparian herbs in reducing soil erosion and nutrient loss under simulated rainfall

Abstract

The native riparian herbs such as Leonotis nepetaefolia (L.) R. Br., Cassia tora L., Ageratum conyzoides L., Parthenium hysterophorus L. and Sida acuta burm f., dominant on the bank of River Damodar in Eastern Jharia Area, Dhanbad (India), were selected to assess experimentally their quantitative role in conserving the soil and reducing water runoff and nutrient (N and P) losses. A total of 42.5 mm simulated rainfall were applied at 30 cm h -1 rain intensity on both vegetated and bare plots. The collected runoff water and eroded soil from each plot were determined in terms of soil, water and nutrient conservation value (CV). Among the vegetated plots, soil CV ranged from 30 to 85% and water CV from 20 to 48%. Nutrient (N and P) CV varied from 22 to 65% for total-N, 48 to 80% for ammonia-N and 50 to 86% for nitrate-N. CV for total-P varied from 40 to 62%, inorganic-P from 42 to 60% and organic-P from 20 to 58%. In a stepwise multiple regression equation comprising four independent variables (canopy cover, litter mass, soil moisture and plant biomass), canopy cover explained 70-88% (P \ 0.01) of variability in conserving soil, water and nutrient. The losses through runoff water and eroded soil from vegetated plots were found to be minimized to a great extent as compared to bare plots. The role of these species in maintaining the texture and fertility status of riparian soil is discussed.

Inhibiting Effects of Vegetation on the Characteristics of Runoff and Sediment Yield on Riparian Slope along the Lower Yellow River

“…Riparian vegetation, which is the last barrier for the highland runoff and sediment transport to the river in the basin, plays an important role in intercepting, filtering and depositing the soil particles of surface runoff, stabilizing river banks and preventing river bank erosion and collapse by enhancing infiltration, reducing runoff and flow velocity and improving soil corrosion resistance [7,12]. Previous studies have explored the relationship between riparian vegetation and soil and water conservation specifically focusing on vegetation type, coverage, root system [13][14][15], structural characteristics of vegetation [16,17], distribution and arrangement of vegetation [18] and the coupled models of vegetation pattern and the soil erosion process [19]. For example, Srivastava et al [13] and Xia et al [14] analyzed the effects of riparian vegetation on slope erosion by creating field simulated rainfall or performing runoff scouring experiments to determine the effect of presence or absence of vegetation on slope erosion.…”

“…Previous studies have explored the relationship between riparian vegetation and soil and water conservation specifically focusing on vegetation type, coverage, root system [13][14][15], structural characteristics of vegetation [16,17], distribution and arrangement of vegetation [18] and the coupled models of vegetation pattern and the soil erosion process [19]. For example, Srivastava et al [13] and Xia et al [14] analyzed the effects of riparian vegetation on slope erosion by creating field simulated rainfall or performing runoff scouring experiments to determine the effect of presence or absence of vegetation on slope erosion. However, the interaction and relative contribution between the vegetation coverage and slope gradient were not taken into consideration in these studies when investigating the inhibiting effects of riparian vegetation on slope runoff and sediment yield; meanwhile the quantitative evaluation of the relevant factors in soil erosion process should also be considered.…”

Ageratum conyzoides L. for the management of pests and diseases by small holder farmers

“…For example, A. conyzoides planted as a riparian wetland herb on the banks of the Rihand River in Renukoot reduced erosion of organic carbon and cationic nutrients and helps in soil conservation (Kumar et al, 1996). A. conyzoides also maintains the texture and fertility of soil along rivers through reducing soil erosion (Srivastava et al, 2009). A. conyzoides was even reported to be used successfully as a substrate for oyster mushroom cultivation that helps to increase its protein content and production time (Nirmalendu and Mina, 2007).…”

Ageratum conyzoides: an alien invasive weed in India.

“…Ageratum conyzoides planted as a riparian wetland herb on the banks of the Rihand River in Renukoot plays a positive role in reducing erosion of organic carbon and cationic nutrients and helps in soil conservation (Kumar et al, 1996). Recently, it has been observed that A. conyzoides helps in maintaining the texture and fertility of soil along the River Damodar riparian zone in Bhowra, as soil erosion was minimized to a great extent following its planting compared with bare areas (Srivastava et al, 2009).…”