On‐Farm Evaluation of Ridging and Residue Management Practices to Reduce Wind Erosion in Niger

Abstract

Wind erosion is regarded as a major contributor to the desertification process in the Sahel, yet little quantitative information is available for that region on soil losses by wind erosion under different land management practices. A 3‐yr, on‐farm experiment was, therefore, set up to assess the effect of ridging and either banded or broadcast millet stover mulches (2000 kg ha−1) on soil loss in a millet‐cowpea intercrop. For wind directions approximately perpendicular to the orientation of ridges and residue bands, sediment mass balances were calculated from the change in horizontal sediment mass fluxes measured across the experimental plots with Big Spring Number Eight sand traps. Mass balance calculations for 16 events over 3 yr indicated an average soil loss of 17.5, 15.4, and 18.0 Mg ha−1 on control plots, and deposition of 15.5, 15.3, and 7.4 Mg ha−1 on banded residue plots in 1995, 1996, and 1997, respectively. Broadcast and banded residue mulches were not significantly different (P = 0.05) in terms of their sediment trapping efficiency. During the same time period, ridges reduced soil losses by an average of 57% compared with the control plots, but their efficiency was reduced to less than 15% after 100 mm of cumulative rainfall as ridges collapsed. Linear regression analysis using the incoming sand fluxes as the independent variable was used to estimate potential soil losses for all events with sediment fluxes <25 kg m−1 irrespective of wind direction. The calculations indicated potential soil losses of up to 79 Mg ha−1 on control plots and deposition of 41 Mg ha−1 on broadcast residue plots in a single year. For wind erosion control, broadcast millet stover mulching constituted the most effective control technique because it effectively protected the soil against erosion and its trapping efficiency is expected to be independent of wind direction.

Green-manure turnip for soybean based no-tillage farming systems in eastern Paraguay

“…The high dry matter production of turnip is advantageous for minimizing soil erosion. Residue mulch on the soil surface can effectively protect the soil against wind erosion (Bielders et al, 2000) and runoff after rainfall .…”

Measurement and data analysis methods for field‐scale wind erosion studies and model validation

“…However, the tillage ridges must be maintained in a rough, non-erodible condition so that previously eroded sediment is not blown back on the field when the wind direction changes. Stabilizing the edge of the field with flat residue or vegetation may be easier to maintain than tillage ridges, especially in the cases of sandy soils for which ridges collapse very quickly (Bielders et al, 2000). If sediment is deposited upon the residue, application of additional residue will be necessary.…”

“…The difference between the incoming and outgoing sediment is the eroded or deposited mass of the area lying between the two measurement locations. This approach was recently used by Bielders et al (2000) to measure the effect of various on-farm management practices to reduce wind erosion in Niger. If wind direction varies from event to event, it is necessary to have sample locations along the study area boundary .…”

Desertification and a new countermeasure in the Sahel, West Africa

“…Until now, techniques such as ridging (Bielders et al 2000), mulching using the stover of the harvested crops (Michels et al 1995b;Sterk and Spaan 1997;Buerkert and Lamers 1999;etc. ), and the establishment of windbreak trees and windbreak barriers (Banzhaf et al 1992;Michels et al 1998;etc.…”