Climate Change Effect on Water Use Efficiency under Selected Soil and Water Conservation Practices in the Ruzizi Catchment, Eastern D.R. Congo
Loading...
Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
Land
Abstract
Concerns have been raised on the effectiveness and sustainability of Soil and Water Conservation
(SWC) practices as adaptation options to climate change and high intra– and inter–annual
rainfall variabilities in eastern Democratic Republic of Congo (DRC). This study was conducted in the
Ruzizi Plain, a dryland area, to assess the performance of maize (Zea mays L.) under two Representative
Concentration Pathways (RCP 4.5 and 8.5) and two SWC practices (tied ridges and conventional
tillage). The AgMIP’s Regional Integrated Assessment (RIA) approach was used to simulateWater
Use Efficiency (WUE) under the Cropping System Model–Crop Environment Resource Synthesis
(CSM–CERES–Maize) of the Decision Support System for Agro–technology Transfer (DSSAT). The
model was calibrated using experimental data from nine cropping seasons (2011–2018) and 100
farms. The model sensitivity was assessed as a function of temperature, water, and SWC practices for
the same environments. Initial conditions of crop management practices were used as input data
for CSM–CERES–Maize. Current climate data were extracted from AgMERRA datasets corrected
with local data for the period of 1980 to 2021. Future climate projections (2022–2099) were obtained
after downscaling the data from the 29 General Circulation Models (GCMS) of Coupled Model
Intercomparison Project 5 (CMIP5) and subsetted to five GCMs based on climate regimes. GCMS
results were a strong indicator that climate change in this DRC dryland will result in an increase
in average annual temperatures for both RCP 4.5 and 8.5, with the highest increase (3.05 C) under
hot/dry conditions for RCP8.5 and the lowest (1.04 C) under cool/dry conditions for RCP 4.5. All
the models selected for five climate regimes for 2022–2099 showed no change in the rainfall trends for
RCP 4.5 (p > 0.05). The models projected yield declines of 5–25%, with less yield losses under tied
ridges as an adaptation practice. The use of efficient SWC practices could therefore be a promising
strategy in reducing potential losses from climate change in drylands of eastern DRC.
Description
Keywords
Climate change scenarios, Cropmodeling, DSSAT, Dryland, Maize, Soil and water conservation
Citation
Bagula, E.M.; Majaliwa, J.G.M.; Mushagalusa, G.N.; Basamba, T.A.; Tumuhairwe, J.-B.; Mondo, J.-G.M.; Musinguzi, P.; Mwimangire, C.B.; Chuma, G.B.; Egeru, A.; et al. Climate Change Effect onWater Use Efficiency under Selected Soil and Water Conservation Practices in the Ruzizi Catchment, Eastern D.R. Congo. Land 2022, 11, 1409. https:// doi.org/10.3390/land11091409