Effects of mulching on soil nutrients and yield of Robusta coffee. (105)
Keywords:Robusta coffee, Mulch materials, Soil characteristics, Low-inputs, Coffee plantations, Ghana
AbstractWith the rising cost of inorganic fertilizers, the current low price of coffee on the international market, and subsequent reduction in coffee farmers' income, there is the need to search for low-input farming strategies in order to reduce cost and improve the income of coffee farmers. One such emerging strategy in the management of nutrients from organic matter in relation to sustainability is the use of mulch. Chromolaena odorata (Siam weed), coffee husk, banana trash, and Tripsacum laxutn (Guatemala grass) that are readily available in and around coffee farms in Ghana were compared for their efficacy as mulch materials and their ability to improve soil fertility and increase coffee yield. Changes in soil characteristics such as total P, available P (using 0.2 N H2SO4 and 0.5 M NaHCO3 extractants), per cent C, Na, Mg, K, and cation exchange capacity of the experimental plots were measured in addition to coffee yield. With the exception of the K and N levels of the soil which were significantly (P < 0.01) influenced by the mulch materials, the changes in the other soil properties were not significant. The mulch materials significantly (P < 0.05) increased coffee yield by 4-158% over the control during the three-year period of the study. However, T. laxum and C. odorata were found to be better mulch materials than coffee husk and banana trash in terms of coffee yield improvement. Mulching in coffee plantations is therefore recommended as one of the low-input management strategies to bring about sustainable production in Ghana.