ENHANCING NUTRIENT AVAILABILITY AND COFFEE YIELD ON ACID SOILS OF THE CENTRAL PLATEAU OF SOUTHERN RWANDA (Published)
Soil acidity is among the major constraints to coffee productivity in Southern Rwanda. An experiment was conducted in 2010 to evaluate lime effect on nutrient availability and cherry yield of Coffee Arabica L. grown on acid soils of Nyamagabe District. The experiment was set in a randomized completely bloc design with two lime treatments (0 and 1.25 t ha-1 Ca(OH2)) applied under eragrostis mulched and non mulched conditions. Results showed that lime increased soil pH and decreased aluminium saturation and enhanced nutrient availability with values varying from 2-35.9 ppm, 3.1-5.5 Cmol (+) kg-1 and 0.57-1.56 Cmol(+) kg-1 for available phosphorus, exchangeable Ca2+ and Mg2+, respectively. Moreover, interaction lime-mulch led to higher N content in the soil (0.19%) and higher cherry yield (8.5t ha-1) compared to the control (3.8 t ha-1). Cherry yield positively correlated with soil pH (r2=0.71), soil calcium (r2=0.56), soil magnesium (r2= 0.53), total N (r2=0.30), available P (r2=0.62) and negatively with aluminium saturation (r2=0.3). Application of lime in mulched coffee is recommended to improve nutrient availability and coffee yield on acid soils of Southern Rwanda
Keywords: Acid soils, Arabica coffee, cherry yield, lime