Abstract:
Maize is a key source of food and livelihood for millions of people in many countries of the
world. However, its productivity is highly constrained by low soil fertility status among other
factors. This experiment was conducted in Omonada and Mana districts in Jimma zone,
Southwestern Ethiopia, between November 2018 and October 2019 to evaluate the effect of
crop residue management (RM) and animal manure storage system (MSS) on soil fertility and
growth, yield and yield components of maize (Zea mays L.). The trial involved two factors
with five levels of RM (control, 25%, 50%, 75% and 100%) and four levels of MSS (control,
open, steel roofed (SR) and grass roofed (GR)) laid out in randomized complete block design
and replicated three times at two locations. Crop phenology (days to 50 % tasseling, silking
and physiological maturity), growth parameters (plant height and leaf area) and yield and
yield components of maize were recorded. It was observed that available NPK, organic
carbon and organic matter in the soil after harvest increased with application of crop residue
and animal manure. Growth, yield and yield components were highly significantly influenced
by location, and RM and MSS treatments, but the three ways interaction was not significant
for all those parameters. The highest value for all maize growth, yield and yield component
parameters was recorded from Omonada district. The highest (6,703.2 kg ha-1) grain yield
was recorded for 100 % followed by 75% residue incorporation with the respective increment
of 15.7% and 14.7% over the control plot. Similarly, GR manure storage system gave the
maximum grain yields (6,887.0 kg ha-1) and resulted in highest values of all plant parameters.
Grain yield was also significantly (P=<0.05) and positively correlated with various yield
attributes of maize, such as cob length, cob weight, number of ears plant-1, number of kernels
row cob-1, kernel number cob-1, kernel number row-1, thousand seed weight, grain yield per
plant, dry biomass yield plant -1, and above ground dry biomass yield hectare -1. The result of
partial budget analysis showed that 75% residue incorporation and GR manure storage
system either alone or in combination gave greater economic benefit with higher MRR. The
combination of 75% crop residue with GR manure gave the highest net benefit (44,882.1Birr
ha-1) with MRR of 721.6%. Therefore, it was concluded that combined application of 75%
crop residue and GR manure storage system can be tentatively recommended for production
of maize in the study area and in other areas with similar agro-ecological conditions.
However, since the experiment was conducted for one season at only two locations, it is
suggested that it has to be repeated over seasons and locations using this and other improved
maize varieties to make a conclusive recommendation.
