Integration of Biochar and Rainwater Harvesting to Improve Pearl Millet ( Pennisetum glaucum ) in Semi‐Arid Regions of Zimbabwe
Andrew Tapiwa KugederaABSTRACT
Introduction
Crop production has been declining in semi‐arid areas over the past two decades due to several biophysical constraints, including soil infertility and water stress induced by low rainfall. The objective of the experiment was to evaluate the effects of biochar and rainwater harvesting techniques on soil moisture content, bulk density, rainwater‐use efficiency, and grain yield in pearl millet in the semi‐arid region of Zimbabwe.
Materials and Methods
The experiment was laid out in a 5 × 3 factorial design with biochar as the first factor at five levels (0, 2.5, 5, 7.5, and 10 t ha −1 ) and rainwater harvesting techniques as a second factor at three levels (tied contour, infiltration pits, and standard contour).
Results
showed that the application of 10 t ha −1 had the highest soil moisture content of 19.7%, which was 131.7% above the control ( p < 0.05). Additionally, the tied contour had the highest soil moisture content, which was significantly higher than that of other rainwater harvesting techniques. Bulk density decreased significantly ( p < 0.05), by an average of 10%, with the application of 5 t ha −1 biochar. Furthermore, rainwater use efficiency was influenced considerably ( p < 0.05), with the highest of 3.5 kg ha −1 mm‐1 from 10 t ha −1 biochar and 3.1 kg ha −1 mm −1 from tied contour. Integration of 10 t ha −1 biochar and tied contour showed the highest rainwater‐use efficiency of 5.11 mm kg −1 ha −1 , which was significant ( p < 0.05) during 2024/25. Pearl millet grain yield was significantly ( p < 0.05) influenced by biochar and rainwater harvesting, with integration of 10 t ha −1 biochar and tied contour having the highest (2085.7 kg ha −1 ) grain yield during 2024/25.
Conclusion
It can be concluded that the use of biochar in sandy loam soils, together with tied contour, increased soil moisture content and improved the grain yield of pearl millet in semi‐arid regions.