Agricultural specialists in Tanzania are urging coffee producers to plant ground-cover vegetation as a defense against worsening weather patterns. Daily News reported that shifting rainfall and temperature trends are degrading soil health, prompting experts to recommend practices that conserve moisture and strengthen soil structure. This strategy is a core component of the Coffee & Climate Toolbox, a platform designed to help farmers and extension workers adapt to changing climatic conditions.
The Tanzania Agricultural Research Institute (TARI-Uyole) evaluated the impact of interplanting Canavalia ensiformis, a legume, with coffee in Mbozi District, Songwe Region. The institute found that the plant’s foliage shields the earth from direct sun and rain, while its decaying leaves add organic matter to the ground. Soil tests from the trial site showed total nitrogen levels rising from 0.10 percent in bare plots to 0.19 percent where the legume was present. Organic carbon also climbed from 1.2 percent to 1.65 percent, and available phosphorus increased from 6.1 to 6.48 milligrams per kilogramme.
Godfrey Wilgod, who coordinates agronomy at the Hanns R. Neumann Stiftung in Tanzania, stated that protecting the soil is vital for preparing farms for climate change. He explained that vegetation cover limits moisture loss and aids water infiltration, while decomposing leaves create a habitat for beneficial organisms like earthworms. Daily News noted that these plants can also suppress weeds, potentially reducing weeding labour and the need for chemical inputs. However, the benefits depend on appropriate management, as cover crops can compete with coffee trees for resources if not carefully controlled.
TARI-Uyole advised farmers to monitor soil moisture and adjust planting density based on local conditions. The institute highlighted the need for multi-season assessments to confirm the long-term effects of this practice on soil fertility. Wilgod described soil protection as a continuous investment rather than a seasonal task, aiming to build a farming system that supports production despite erratic rainfall and rising temperatures. The Coffee & Climate Toolbox offers practical advice on integrating these cover crops with other methods, such as mulching and rainwater harvesting, to enhance overall farm resilience.