The Effectiveness of Organic and Inorganic Mulch in Conserving Soil Moisture

Mohamed Salumu is a third year-student at Sokoine University of Agriculture (SUA) pursuing a Bachelor of Science in Agronomy. For the completion of his studies he is currently conducting a research project at the SUA Farm where he assesses the effectiveness of organic and inorganic mulch in conserving soil moisture. The research project extends over a period of seven months in total, including land preparation, application of mulching materials in the plots among others and data collection and analysis which is currently being undertaken from April to May.


On 12 plots of 20m² each, maize crops were planted which divide into four different treatments and three replications. The different mulching treatments are the following: Rice husks and Mbagalala grasses for organic mulch, nylon cover for inorganic mulch and a IMG_0668control plot without any mulch. In general, mulches prevent the soil from losing water through evaporation and enable it to better absorb irrigation and rainfall. Whereas inorganic mulches don’t decompose and therefore require less work, organic materials also contain nutrients and improve soil structure. Other potential benefits of using mulches include weed control, reduced soil erosion, the maintenance of optimal soil temperatures and increased nutrient levels of the soil. Based on the analysis of his data, Mohamed recommends small-scale farmers to use Mbagalala grasses or rice husks as mulch. They are a cost-efficient alternative to inorganic materials and don’t differ significantly in performance compared to the latter. While the preservation of soil moisture with nylon mulch is 20.33%, rice husks preserve 20.27% and the grasses 19.54%. When applying organic mulches, one has to consider that due to strong rainfalls, repeated application of mulching materials may be demanded, as decomposition is accelerated or rice husks are washed away.

Mohamed is convinced that his results will eventually help not only his own family that is also involved in agriculture but many more small-scale farmers in the region of Morogoro and beyond. “It’s important to equip them with knowledge IMG_0659and skills about effective and at the same time available and affordable mulching materials that are environmentally-friendly.” Through his attendance in the Workshop for Participatory Research Design (WPRD) organized by SAT he has learned about the widespread problem among farmers of maintaining soil moisture and decided to deal with this issue through scientific research. This kind of collaboration, taking into account commonly used methods like Mbagalala grasses for mulch and assessing their effectiveness through in-depth research and thereby eventually improving their application, is what really makes for embracing the full potential of participatory organic agriculture.