AFRICA AGRICULTURE STATUS REPORT 2016

Table 5.2: Correlation between factors and cereal output and yield by regional group
Pearson Correlation Coefficient
Cereal output
Cereal yield
COMESA SADC ECOWAS COMESA SADC ECOWAS
Agricultural inputs and factors
Fertilizer consumption (kg/ha) 0.382** -0.204 -0.067 0.359** 0.051 0.601**
Machinery (tractors/100 km 2 of arable land) -0.153* -0.446** 0.056 0.610** -0.084 0.307**
Land under cereal production (1,000 ha) 0.851** 0.885** 0.932** -0.262** 0.311** 0.019
Rural Population (1,000) 0.778** 0.765** 0.825* * -0.341** 0.222** 0.136*
Source: IBRD/World Bank (2015)
The slow rate of growth in crop yield in SSA,
despite the significant increases in the release
of improved varieties, may be due to minimal
adoption of complementary technologies, such
as fertilizer and improved crop management
practices. Moreover, while not reflected in average
yields, the increased use of improved varieties
may still have contributed to increased efficiency
in using factors of production (IFAD, 2016).
Is output expansion a result of agricultural
intensification or extensification?
Evidence suggests that, unlike the agricultural
output growth path observed for Asia in the
early days of the Green Revolution, which has
intensified in recent decades, the increase in
agricultural output in SSA has not been achieved
through intensification. That is, the efficient use
of non-labor, non-land inputs (such as improved
crop varieties and fertilizers), but rather through
extensification, relying on the expansion in
cropped land area, and the use of manual labor 5 .
Figure 5.5 illustrates the cases of SSA and Asia,
using the cereal yields indicators referred to before
and the cereal area planted index (1961 = 100).
Examining this analysis across the three subregions
of SSA shows that SADC and ECOWAS
countries experience lower and slower yield
growth and have a relatively faster land area
expansion than COMESA countries (Figure 5.6)
Under a situation where fertilizer use remained
very low, output growth has relied almost
exclusively on cropped area extensification.
Results in Figure 5.6 support this conclusion for
the SADC and ECOWAS countries. In effect, the
results show that along with output growth, there
was an increase in land area cultivated and a
stagnation in yield. This was less so for COMESA
countries, where, although levels of fertilizer use
per hectare were relatively low, intensification
(including efficient use of fertilizer, improved
seeds, agricultural practices, etc.) seems to have
played a relatively more important role resulting in
relatively higher yields.
Analysis of inputs and factors impacting
cereal output and yields
For SSA as a whole, correlations of cereal output
and fertilizer consumption, land area under cereals,
and size of the rural populations in the different
countries reveal a strong positive and statistically
significant correlation between land area planted
and output (r = 0.909, 1 percent) and with rural
population size (r = 0.789, 1 percent). This was
not the case with fertilizer consumption, which had
an insignificant correlation with output (r = 0.030).
Overall, this agrees with the previous analysis
that output expansion has essentially been driven
by expansion in cropped land area and reliance
on abundant manual labor. The use of improved
seeds also increased in many countries, but
remains insufficient to boost productivity, unless
combined with complementary technologies,
especially fertilizer in low-fertility African soils.
Looking at results by regional economic group,
fertilizer was statistically correlated with cereal
yield in COMESA and ECOWAS countries, but
not in SADC countries (Table 5.3). Agricultural
machinery was positively associated with
agricultural productivity, but yielded a small but
negative effect on aggregate output 6 . Overall and
despite some regional differences, agricultural
productivity and intensification at the household
level is extremely low in SSA.
5
Evidence, as
discussed in
the previous
section,
indicates that
while the use
of modern
varieties in key
crops have
increased in
SSA, most
countries are
still lagging
behind.
Disparities also
exist in fertilizer
use and overall
increase in
the levels of
use have been
unimpressive.
6
The signs
of these
relationships
hold for the
sample of all
countries. The
relationship was
not statistically
significant for
cereal output
(ECOWAS) and
cereal yield
(SADC). These
results should
be examined
with caution,
due to limited
variation in
the tractors
variables and
the limited
sample size.
112 AFRICA AGRICULTURE STATUS REPORT 2016