Maize (
Zea mays
L.) is the most widely grown cereal in the world, accounting for
1,116.34 MT of production in 2019/2020. In Africa, this crop represented
approximately 56% of the total cultivated area from 1990 to 2005. About 50% of the
African population depends on maize as a staple food and source of carbohydrates,
protein, iron, vitamin B, and minerals. Lately, maize has become a cash crop which
contributes to the improvement of farmers' livelihoods. For example, the Strategic Plan
for Agricultural Transformation (SPAT) III outlined that fertilizer availability in
Rwanda should increase to 55,000 MT per year, while fertilizer use should increase
from 30 kg/ha in 2013 to 45 kg/ha for the 2017/18 cropping season. Only inorganic
fertilizers are currently being used in maize production in Rwanda. This research was
conducted to assess the effects of liquid (CBX: Complete Biological Extract) and
granular fertilizers on maize crop yields in Rwanda. The study was conducted in the
fields of the Rwanda Agriculture and Animal Resources Development Board (Rubona
Station) during the 2018/2019 cropping season. Analysis of variance (ANOVA) was
used to determine whether differences between treatments were statistically significant,
with the threshold for statistical significance set at p < 0.05. Aboveground biomass
differed significantly between treatments, with maximum and minimum values of
11,475 kg and 7,850 kg, respectively, being observed. Furthermore, the harvest index
differed significantly between treatments, with minimum and maximum values of
0.2136 and 0.33, respectively, being observed. Grain yield also differed significantly
between treatments, with the highest value (3,053 kg/ha) observed for a treatment
which applied liquid and granular fertilizer at equal proportions (treatment 8), and the
lowest one was found in treatment 3 with 1,852 kg/ha. In this study, the gap between
the lowest and highest grain yields was about 39.3%. In conclusion, the combination of
organic liquid fertilizer and granular fertilizer can significantly increase the grain yield
of maize in Rwanda.
