Socioeconomic characteristics of the sample households.
The study revealed that 81% of households (HHs) were male-headed, with 72.4% from lowlands, 92.2% from midlands, and 80.0% from highland regions. The remaining 19% of households were female-headed. This result is similar to that of the national census, which showed that women account for approximately 16% of HHs in rural areas of the country[34],[35].
Furthermore, details regarding the age group of the respondents revealed that the majority (37.1%) of the HH heads were 50 years and older, whereas a few (7.8%) HH heads were between 20 and 29 years of age. From the agroecological perspective, 37.1% (29.4% from highlands, 49.6% from midlands, and 36.2% from lowlands) of the surveyed headed households were 50 years and older, followed by 35.6% (48.2% from highlands, 29.2% from midlands, and 23.3% from lowlands), who were between 40 and 49 years of age. The mean age of the respondents was 45.64 years, with a standard deviation of 11.45 years.
In terms of marital status, approximately 82.5% of the surveyed-headed households were married, followed by 9.0% who were divorced and 6.0% who were single-headed. Additionally, 57.1% (71.8% from the highlands, 36.3% from the midlands, and 56.0% from the lowlands) of HHs were from families of 4–6 persons, 18.5% from 7–8 members, and 17.5% from 1–3 families. The average family size was five persons per HH, which is similar to a previous report[35] that revealed an average rural area of the country had approximately five individuals (5.2 in rural areas and 3.6 in towns).
Concerning educational status, approximately 38.6% (49.4% from highlands, 26.5% from midlands, and 34.5% from lowlands) of the HHs replied that they attended basic education levels (grades 5–8). Approximately 30.8%, 22.1%, and 8.5% of the HHs sampled in all the AEZs replied that they had attended primary (grades 1–4), secondary general, and illiterate schools, respectively. With respect to religion, the largest percentage of HHs were Orthodox Christians (54.6%), Muslims (44.4%), and Protestants (1.0%) (Table 1).
Table 1
Respondents' socioeconomic characteristics across the AEZs. Note: The numbers in columns (1)–(4) are percentages. M (s.d.) in column (5) is the mean value for age, family size, and education status of all respondents, and its standard deviation is given in parentheses.
Source: Author's survey (2022).
Variable
|
Response
|
Farmer Agro-ecological Zone
|
Total
|
M (s.d.)
|
Highland (1)
|
Midland (2)
|
Lowland (3)
|
(4)
|
(5)
|
Sex
|
Male
|
80.0
|
91.2
|
72.4
|
81.0
|
|
Female
|
20.0
|
8.8
|
27.6
|
19.0
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
Age
|
20–29
|
5.9
|
7.1
|
11.2
|
7.8
|
45.64 (11.45)
|
30–39
|
16.5
|
14.2
|
29.3
|
19.5
|
40–49
|
48.2
|
29.2
|
23.3
|
35.6
|
50 and more
|
29.4
|
49.6
|
36.2
|
37.1
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Marital status
|
Single
|
6.5
|
2.7
|
8.6
|
6.0
|
|
Married
|
79.4
|
93.8
|
75.9
|
82.5
|
Divorced
|
12.9
|
1.8
|
10.3
|
9.0
|
Widowed
|
1.2
|
1.8
|
5.2
|
2.5
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
Family size
|
1–3
|
13.5
|
17.7
|
23.3
|
17.5
|
5.37 (2.38)
|
4–6
|
71.8
|
36.3
|
56.0
|
57.1
|
7–8
|
13.5
|
27.4
|
17.2
|
18.5
|
9 and above
|
1.2
|
18.6
|
3.4
|
6.8
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
Education status
|
Illiterate
|
7.1
|
13.3
|
6.0
|
8.5
|
5.84 (3.18)
|
Primary
(Grade 1–4)
|
28.2
|
51.3
|
14.7
|
30.8
|
Basic (Grades 5–8)
|
49.4
|
26.5
|
34.5
|
38.6
|
Secondary (9–12)
|
15.3
|
8.8
|
44.8
|
22.1
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
Religion
|
Muslim
|
36.5
|
61.1
|
39.7
|
44.4
|
|
Orthodox
|
61.2
|
38.9
|
60.3
|
54.6
|
Protestant
|
2.4
|
0.
|
0.
|
1.0
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
Main cereal crop
|
Barley and wheat
|
87.6
|
75.2
|
0.0
|
58.6
|
|
Maize
|
12.4
|
21.2
|
12.1
|
14.8
|
Sorghum and teff
|
0.0
|
3.5
|
87.9
|
26.6
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
Crop production of sample households.
Barley and wheat (58.6%), sorghum and teff (26.6%), and maize (14.8%) were the major cereal crops produced in the study area. Barley and wheat were the major cereal crops, accounting for 87.6% of the highland (Balo Amina) and 75.2% of the midland (Homa Abu), whereas sorghum and teff, accounting for 87.9%, were the dominant cereal crops in the lowland (Melka Olifigi) AEZ.
Perception of change in climate variability by smallholder farmers.
Farmers across the AEZs were asked to rate their knowledge of climate change and perceptions of any changes in temperature and rainfall (late, early, and erratic rainfall) in the study area. Moreover, the Pearson correlation test was used to determine the important socioeconomic factors that influence farmers' perceptions of climate change (temperature and rainfall).
The overall survey results in the three AEZs revealed that approximately 98.0% of the HHs had replied that they were aware of climate change before, and the remaining 2.0% did not have any clue at all. The study results also revealed variations among the AEZs. A number (98.3%) of HH heads in the lowlands were aware of climate change before the HHs in the midland (98.2%) and highland (97.6%) AEZs. Regardless of agroecology, the survey results also revealed that 51.6%, 41.9%, 3.3%, and 3.3% of the HHs knew about climate change to a reasonable extent, little, to a great extent, and did not have any clue at all, respectively. Similarly, the study results revealed differences among the AEZs in terms of farmers' extent of knowledge about climate change. Most of the smallholder farmers in the midlands (65.5%) replied that they knew little about climate change, whereas most HHs in the highlands (65.9%) and lowlands (49.1%) replied that they knew to a reasonable extent about climate change. This implies that most of the sampled respondents in the study areas were aware of climate change.
Farmers were asked again to respond to changes in climate variability (temperature and rainfall) in their locality. Accordingly, the overall survey results in the three agroecological areas indicated that the majority (98.5%) of the HHs had an equal understanding of the climate variability of temperature and rainfall.
Moreover, farmers' perceptions of changes in the climate variability of temperature and rainfall varied across the three AEZs. More HHs in the highland (98.8%) than in the midland (98.2%) and lowland (98.3%) AEZs experienced significant temperature changes. Moreover, the statistical analysis of the perception of rainfall change also revealed significant variation among the different AEZs. A significant rainfall change was perceived more in the lowland (100%) than by farmers in the midland (98.2%) and highland (97.6%) AEZs. Regardless of agroecology, the survey results also revealed that 51.6%, 41.9%, 3.3%, and 3.3% of the HHs knew about climate change to a reasonable extent, little, to a great extent, and did not have any clue at all, respectively. Similarly, the study results revealed differences among the AEZs in terms of farmers' extent of knowledge about climate change.
The overall survey results indicated that 87.5%, 10.8%, and 1.8% of the HHs perceived an increase, a decrease, and did not know the variability in rainfall starts late in their local area, respectively. Similarly, the majority (86.5%) of the respondents replied with an increase in erratic rainfall, followed by 10.8% with decreases, 1.5% with no change, and 1.3% without a clue. In the rainfall that ends early, 81.5%, 17.3%, and 1.3% of the household heads experienced an increase, a decrease, and no clue at all, respectively (Table 2).
Table 2
Farmers' perceptions (%) of changes in climate and its correlation with socioeconomic factors. Note: The numbers in columns (1)–(4) are percentages. Positive (+) and negative (-) signs in the correlation indicate direct and indirect relationships, respectively. Asterisks (**) indicate the correlation is significant at the < 0.01 level (two-tailed); asterisks (*) indicates the correlation is significant at the < 0.05 level (two-tailed).
Source: Author's survey (2022).
Variables
|
Responses
|
Farmer Agroecological Zone
|
Total
|
|
Highland (1)
|
Midland (2)
|
Lowland (3)
|
(4)
|
|
Have you heard of climate change before now?
|
Yes
|
97.6
|
98.2
|
98.3
|
98.0
|
|
No
|
2.4
|
1.8
|
1.7
|
2.0
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Have you noticed a significant temperature change?
|
Yes
|
98.8
|
98.2
|
98.3
|
98.5
|
|
No
|
1.2
|
1.8
|
1.7
|
1.5
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
To what extent do you know about climate change?
|
Do not know
|
2.9
|
1.8
|
5.2
|
3.3
|
|
Know little
|
25.9
|
65.5
|
42.2
|
41.9
|
|
To a reasonable extent
|
65.9
|
32.7
|
49.1
|
51.6
|
|
To a great extent
|
5.3
|
0.0
|
3.4
|
3.3
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Have you noticed a significant rainfall change?
|
Yes
|
97.6
|
98.2
|
100.0
|
98.5
|
|
No
|
2.4
|
1.8
|
0.0
|
1.5
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Have you observed/noticed any changes in rainfall starting late?)
|
Decreased
|
18.2
|
3.5
|
6.9
|
10.8
|
|
Increased
|
78.8
|
94.7
|
93.1
|
87.5
|
|
No change
|
0.0
|
0.0
|
0.0
|
0.0
|
|
I do not know
|
2.9
|
1.8
|
0.0
|
1.8
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Have you observed/noticed any changes in rainfall that end early?
|
Decreased
|
18.2
|
3.5
|
29.3
|
17.3
|
|
Increased
|
80.0
|
94.7
|
70.7
|
81.5
|
|
No change
|
0.0
|
0.0
|
0.0
|
0.0
|
|
I do not know
|
1.8
|
1.8
|
0.0
|
1.3
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Have you observed any changes in erratic rainfall?
|
Decreased
|
20.6
|
1.8
|
5.2
|
10.8
|
|
Increased
|
75.3
|
96.5
|
93.1
|
86.5
|
|
No change
|
2.4
|
0.0
|
1.7
|
1.5
|
|
I do not know
|
1.8
|
1.8
|
0.0
|
1.3
|
|
Total
|
100.0
|
100.0
|
100.0
|
100.0
|
|
Pearson correlation between socioeconomic factors, rainfall, and temperature.
|
Variables
|
Socioeconomic factors
|
Farmer AEZs
|
Gender
|
Age
|
Marital status
|
Family size
|
Education level
|
|
Rainfall
|
Pearson Correlation
|
.127*
|
.267**
|
.088
|
.225**
|
− .016
|
− .177**
|
|
|
Sig. (two-tailed)
|
.011
|
.000
|
.078
|
.000
|
.747
|
.000
|
|
Temperature
|
Pearson Correlation
|
− .070
|
.154**
|
.101*
|
.179**
|
− .061
|
− .123*
|
|
|
Sig. (two-tailed)
|
.164
|
.002
|
.044
|
.000
|
.226
|
.014
|
|
Moreover, 78.8% of respondents from the highlands and the same percentages from the midlands and lowlands 94.7% and 93.1%, respectively replied an increase in the rainfall starts late in the study area. Nonetheless, an increase in the incidence of irregular rainfall was felt by 96.5% of respondents from the midlands, (93.1%) of respondents from the lowlands, and (75.3%) from the highlands.
The results of the correlation analysis between socioeconomic variables and temperature changes revealed a significant (positive) relationship between gender and marital status at the < 0.01 level and a (negative) correlation with educational status at the < 0.05 level. Gender, age, marital status, and education level are important socioeconomic factors that influence farmers' perceptions of temperature variability (Table 2). Moreover, farmers' AEZs, gender, and marital status were found to have a significant (positive) correlation with factors that influence farmers' perceptions of rainfall variability, and it had a (negative) correlation with educational attainment at the < 0.01 level.
Perception of the impacts of climate phenomena on crop production by farmers.
To capture perceptions of climate change impacts, farmers were asked about the impacts of principal climatic parameters (rainfall and temperature) on crop production over the last ten years. The impacts of each climate parameter were categorized as high, medium, low, and no (Fig. 1). Accordingly, regardless of agroecology, the survey results indicated that 48.6%, 36.1%, 12.8%, and 2.5% of the HHs perceived the variability in temperature to result in high, medium, low, and no impact on crop production in their local area, respectively. Similarly, the overall results indicated that the majority (42.9%) answered that rainfall variability has had a medium influence on crop production, followed by 41.1% with high impact, 14.3% with low impact, and 1.8% with no impact.
Moreover, the results revealed variations among the AEZs. A large number (58.6%) of HH heads in lowland agroecology responded that rainfall variability resulted in high impacts on crop production, whereas most of the farmers in highlands (42.9%) and midlands (61.1%) replied that rainfall variability resulted in a medium impact on crop production.
Additionally, the largest percentage of respondents perceived that rains occurred more erratically, started late, and ended early as a medium factor affecting their crop production. For instance, 68.1% and 16.3% of the farmers perceived that rains started late had medium and high impacts on crop production, respectively, over the last 10 years, whereas 15.1% and 0.5% of the farmers replied that rains had low and no impacts on their crop production, respectively.
However, the medium impacts of late-started rainfall on crop production also revealed some percentage differences among the AEZs in terms of farmers' perceptions. More HHs in the lowland (72.4%) than in the highland (70.3%) and midland (60.4%) AEZs perceived the medium impacts of late-started rainfall on food crop production.
Overall, 66.2% of the HHs perceived a medium impact on crop production from early ending rains in their local area. Moreover, the medium impact on crop production because of rains ended early for the highland, midland, and lowland AEZs at 71.9%, 62.2%, and 62.1%, respectively. The results also indicated that, regardless of agroecology, rains became more erratic, and the largest percentage of the respondents, 238 (60.4%), replied as having a medium impact on crop productivity over the last 10 years, followed by 98 (24.9%) with a high impact, 52 (13.2%) with a low impact, and 6 (1.5%) with no impact.
Despite this awareness of the climate, most HHs do not perceive climate change to be the greatest risk to their livelihoods and success. Since the general interviewed farmers, only approximately half of the HHs replied that rainfall (41.1%) and temperature (48.6%) variability have had a high impact on their crop production over the last 10 years.
Moreover, among all the interviewed HHs, the largest percentage (60.4%, 68.1%, and 66.2%) of the respondents perceived that rains became more erratic, started late, and ended early, respectively, as a medium climatic factor that affected their crop production.
The trend of climate variability and crop yield.
Linear regression and correlation tests were used to examine the trends and changes over time in the climate variables from 1990–2019 and to examine the relationships between the annual rainfall and crop yield in the study district. Accordingly, the results from the meteorological analysis revealed that the annual temperatures in the district showed statistically significant increasing trends at the < 0.01 level, whereas the annual rainfall showed insignificant (Ρ > 0.05) decreasing trends over the past 30 years.
Moreover, for the period from 1990–2019, the mean annual temperature of the Gassera district increased by 0.037°C per year (Fig. 2). As shown in the time series plot with the estimated linear trend, the mean annual rainfall decreased by 2.924 mm/year during the same period. The lowest annual mean temperatures and rainfall were recorded in 1993 and 2015, respectively, whereas the highest annual mean temperatures and rainfall were observed in 2015 and 1992, respectively.
With respect to the relationship between annual rainfall and crop production, the value of crop yield is presented in Fig. 2. The results revealed that as the amount of annual rainfall increased, the crop yield also increased. The values of barley, wheat, sorghum, maize, and teff yields (Qt/ha) were high in the years 2010 (with a rainfall of 1368 mm) and 2014 (with a rainfall of 1010 mm). The lowest yields of barley, wheat, sorghum, and teff yield crops were obtained in 2012 (with a rainfall amount of 826 mm), except for the yield of maize.
Effect of rainfall on yield and loss of crop yield by smallholder farmers.
Moreover, correlation and regression were used to investigate the effects of or relationship between our response variable (crop production) and the explanatory variables of annual rainfall in the study area.
Effect of annual rainfall on crop production.
Below are the results of the ANOVA, the linear regression analysis, and the model summary. The model coefficient, as shown in Table 3, was determined to be .989, which indicates that 98.9% of the variation in how rainfall changes affect crop output in Quintal (Qt) of the study region can be accounted for by the variables in the model. The model explained approximately 96.3% of the variability in crop yield, according to the adjusted R square. The linear correlation coefficient was displayed as R.995a, and the combination of these variables strongly predicted the dependent variables, as indicated by Sig.026.
Table 3
Model summary, ANOVA, and results of the linear regression analysis. Note: Barley production in Quintal (continuous); Wheat production in Quintal (continuous); Sorghum production in Quintal (continuous); Maize production in Quintal (continuous); and Teff production in Quintal (continuous). Positive (+) and negative (-) signs indicate direct and indirect relationships, respectively. Asterisks (*) are statistically significant at the\(\:\:<0.05\) level (two-tailed); ns, nonsignificant.
Model summary b
|
Model
|
R
|
R Square
|
Adjusted
R Square
|
Std. error of the estimate
|
Sig. F Change
|
|
1
|
.995a
|
.989
|
.963
|
45.93546
|
.026
|
|
b indicates all predictors/independent variables: (constant).
|
ANOVA a
|
Model
|
Source
|
Sum of Squares
|
df
|
Mean Square
|
F
|
Sig.
|
|
1
|
Regression
|
391389.174
|
5
|
78277.835
|
37.097
|
.026b
|
|
Residual
|
4220.132
|
2
|
2110.066
|
|
|
|
|
Total
|
395609.306
|
7
|
|
|
|
|
a indicates the dependent variable: Annual rainfall (mm),\(\:\:\text{a}\text{n}\text{d}\:\)b indicates the independent variables: the value of crop production in Quintal (Qt).
|
Model
|
Variables
|
Coefficient
|
Std. Deviation
|
t-value
|
P-value
|
Correlations
|
|
1
|
(Constant)
|
-312.894
|
|
-1.646
|
.026*
|
|
|
Barley production (Qt)
|
.080
|
269382.617
|
.564
|
.629 ns
|
.673
|
|
Wheat production (Qt)
|
.896
|
1044607.093
|
4.714
|
.042*
|
.141
|
|
Sorghum production (Qt)
|
-1.274
|
71529.463
|
-6.165
|
.025*
|
− .165
|
|
Maize production (Qt)
|
− .645
|
179087.131
|
-5.621
|
.030*
|
− .540
|
|
Teff production (Qt)
|
1.428
|
140918.535
|
6.462
|
.023*
|
.176
|
|
The least-squares estimator of the intercept, β0, was found to have a value of -312.894 and was labeled a constant. The least-squares estimators of the five partial slopes (080, .896, -1.274, − .645, and 1.428) represented barley, wheat, sorghum, maize, and teff production in Quintal, respectively. Accordingly, wheat, sorghum, maize, and teff production in Quintal (Qt) were found to be significant at the < 0.05 level variables that predicted the response variable effects of annual rainfall change on crop production in the study area at a 5% level of significance. The \(\:\:\text{P}\)-values for wheat (0.042) and teff (0.023) crop production in Quintal were found to be positively significant variables affecting crop production. Thus, the study results revealed that the amount of wheat production increased by 0.89 Qt as the amount of rainfall increased by one millimeter. Similarly, the amount of teff production increased by 1.43 Qt as the amount of rainfall increased by one millimeter.
Moreover, the \(\:\:\text{P}\)-values for sorghum (0.025) and maize crops (0.030) were much lower than 0.05 and were found to be significantly negatively related to the effects of annual rainfall change on crop production at the 5% level of significance. For instance, as the amount of annual rainfall increased by one millimeter, the amount of sorghum production decreased by 0.645 Quintal (Qt).
This might be because of climate variability and extreme events of a high level of seasonal rainfall variability, unexpected decreases in rainfall, and the frequent occurrence of drought episodes in the study area. For instance, a study conducted between 1983 and 2012 on climate variability across possible crop-growing regions in Ethiopia revealed a considerable shift in the rainfall coefficient of variation, with greater interannual variability than annual variability in the Bale Zone [12].
Climate-induced loss of crop yield by smallholder farmers.
Moreover, farm householders were asked about the most vulnerable human elements, the outcome of climate change with multiple optional responses, and the estimated amount of crop yield loss (in kg) over the last ten years due to climate change. Accordingly, regardless of agroecology, the survey results revealed that the most vulnerable family members (human elements) in the study area to the impacts of climate change were 84.5% (337) women, 77.4% (309) children, 44.1% (176) elders, and 2.5% (10) men. In addition, regardless of agroecology, all respondents (100.0%) reported that the decline in crop yield was the outcome of climate change, followed by food shortages (97.2%) and increased food prices (92.2%) (Table 4).
However, only 40.6%, 24.6%, and 23.6% of the smallholder farmers in the three AEZs agreed that soil nutrient depletion, erosion hazards, and early maturity of crops were the outcomes of climate change, respectively. Thus, approximately two-fifths of the farmers did not consider soil nutrient depletion, erosion hazards, early cropping, or flooding as potential outcomes of climate change and variability. This implies that all the respondents in the three AEZs confirmed that the decline in crop productivity over the last few years in the study area was the principal outcome of climate variability.
In addition, the HH heads in the three AEZs that responded to the decrease in crop yield were again asked to mention the total estimated amount of loss of crop yield (in kg) due to climate change in the last ten years. Accordingly, survey results from 399 smallholder farmers revealed that, on average, 2,700 kg of crop yield was lost because of climate change (Table 4).
Table 4
Farmers' perceptions of the outcome and amount of crop yield loss (kg). s.d. is the standard deviation for the farmers' estimated amount of crop yield loss (kg).
Source: Author's survey (2022).
Variables
|
Responses
|
Frequency
|
Percentage
|
|
Outcome of climate change (Multiple answer option)
|
Decrease in crop yield
|
399
|
100.00
|
|
Increase in crop yield
|
22
|
5.5
|
|
Food shortage
|
388
|
97.2
|
|
Food price increase
|
368
|
92.2
|
|
Early maturity of the crops
|
94
|
23.6
|
|
Flooding
|
74
|
18.5
|
|
Erosion hazard
|
98
|
24.6
|
|
Soil nutrient depletion
|
162
|
40.6
|
|
Who has been most affected by climate change?
|
Children
|
309
|
77.4
|
|
Women
|
337
|
84.5
|
|
Men
|
10
|
2.5
|
|
Elders (50 and more)
|
176
|
44.1
|
|
Farmers estimated the amount of loss of crop yield due to climate change (in kg) for the last ten years.
|
Variables
|
Responses
|
|
|
|
|
|
|
Estimated crop yield loss across AEZs and crop type.
|
AEZs
|
Crop type
|
Mean
|
Range
|
s.d.
|
Variance
|
Sum
|
|
Highland
|
Barley and wheat
|
1,409.53
|
5,800
|
1,074.03
|
1,153,531.14
|
239,620
|
|
Midland
|
Maize
|
2,902.65
|
11,000
|
2,189.93
|
4,795,796.46
|
328,000
|
|
Lowland
|
Sorghum and teff
|
4,396.55
|
9,600
|
2,651.63
|
7,031,118.44
|
510,000
|
|
|
Total
|
|
2,700.80
|
11,800
|
2,330.85
|
5,432,864.18
|
1,077,620
|
|
Statistical analysis also clearly revealed that the range, variance, and total amount of crop yield lost because of climate change were 11,800 kg, 5,432,864 kg, and 1,077,620 kg, respectively. From an agroecological perspective, the study results from the sample respondents revealed that the highest (510,000 kg) total amount of crop yield loss was found in lowland (Melka Olifigi) agroecology, followed by midland/Homa Abu (328,000 kg) and highland/Balo Amina (239,620 kg) in the last ten years, resulting from climate change.
This implies that lowland agroecology has the greatest crop yield loss, which is most affected by climate change variability, whereas highland agroecology is the least affected by climate change variability. The results from MLR also revealed that, compared with farmers living in midland and lowland agroecology, farmers living in highland agroecology experienced a decrease in crop yield of 143.44 kilograms per hectare (kg ha− 1). The results of the FGDs and interviews verified that the climate was changing and confirmed that the decline in crop productivity was the principal outcome of climate variability over the years in the study area.
Impacts of climate variability on crop production.
This section addresses the findings of the MLR model, that revealed which parameter was more responsible for productivity fluctuations and to what extent the independent variables explained the effects of climate variability on the crop production loss of smallholder farmers.
Goodness of fit and estimation of multiple regression coefficients.
The SPSS software was used to find the \(\:{\text{R}}^{2}\) and least squares estimates for \(\:{\beta\:}_{0},\:{\beta\:}_{1},\:{\beta\:}_{2},\:{\beta\:}_{3},\:{\beta\:}_{4},\:{\beta\:}_{5},\:{\beta\:}_{6},\:{\beta\:}_{7},\:{\beta\:}_{8},\:{\beta\:}_{9},\:{\beta\:}_{10},\:\text{a}\text{n}\text{d}\:{\beta\:}_{11},\:\) in the multiple regression models. The results are displayed in the table below. Table 5 shows that the model \(\:{\:\text{R}}^{2}\:\) value was .956, which indicates that the variables in the model accounted for 95.6% of the variability in the consequences of climate change on the loss of agricultural output experienced by smallholder farmers (kg ha− 1). Moreover, the adjusted R square in this instance showed that the model explained almost 95.5% of the variability in farmers' crop production loss.
The multiple correlation coefficient is displayed as R.978a, and Sig.000 suggested that the variables together significantly (P < 0.05) predicted the dependent variables. Furthermore, the coefficients for each variable in the model related Y to X1, X2... X11 shows how much one could anticipate that crop yield loss would change as a result of climate variability given a one-unit change in that variable's value and the assumption that all other variables in the model would remain constant.
The least-squares estimator of the intercept, β0, was found to have a value of 871.309 and was labeled constant. The least-squares estimators of the eleven partial slopes − 143.440, -134.712, 221.591, -25.802, 221.591, -25.802, 215.850, -93.624, 326.631, -28.970, -68.180, 63.814, and 49.779 represented farmers' agroecology type (highland, midland, and lowland), sex, religion, to rate their knowledge of climate change, whether they have access/primary sources of information regarding climate change or not, use of chemicals (such as herbicides or insecticides), use improved seed varieties of crops, marital status, education status, age of household heads, and family size, respectively. Table 5 presents the point estimation of the regression coefficients and the P-values of the variables.
Table 5
Model summary, ANOVA, and results of multiple linear regression analysis. Note: HH head agroecology type (highland = 0, midland = 1, and lowland = 2), headship type (male = 0, female = 1); religion, HH head religion affiliation (Muslim = 0, orthodox = 1, protestant = 2, catholic = 3, others = 4); HH head rating their knowledge status about climate change, (do not know = 0, knew little = 1, to a reasonable extent = 2, to a great extent = 3); do farmers have access/ primary source of information regarding climate change (did not have = 0, have = 1); HH head use of chemicals such as herbicide, insecticide (not use = 0, use = 1); HH head use of improved seed varieties of crops (not use = 0, use = 1); marital status (single = 0, married = 1, divorced = 2, widowed = 3); HH head education status, maximum class attended by the household head (continuous); age of household head in years (continuous); family size, total family size in HH (continuous). Positive (+) and negative (-) signs indicate direct and indirect relationships, respectively. Asterisks (*) are statistically significant at the < 0.05 level; ns, nonsignificant.
Source: Author's survey (2022).
Model summary b
|
Model
|
R
|
R Square
|
Adjusted
R Square
|
Std. error of the estimate
|
Sig. F Change
|
1
|
.978a
|
.956
|
.955
|
72.90632020
|
.000
|
b indicates all predictors/independent variables: (constant).
|
ANOVA a
|
Model
|
Source
|
Sum of Squares
|
df
|
Mean Square
|
F
|
Sig.
|
1
|
Regression
|
45123208.672
|
11
|
4102109.879
|
771.751
|
.000b
|
Residual
|
2057033.300
|
387
|
5315.332
|
|
|
|
Total
|
47180241.972
|
398
|
|
|
|
a indicates the dependent variable: the value of farmer's yields loss of crop (kg ha− 1) and b indicates predictors: (constant), family size, and use of any insecticide/pesticide on a farm for cultivation within the last two years.
|
Model
|
Variables
|
Coefficient
|
Std. Err
|
t–value
|
Ρ–value
|
1
|
(Constant)
|
871.309
|
35.305
|
24.679
|
.000*
|
Farmer's agroecological zone
|
-143.440
|
4.622
|
-31.035
|
.000*
|
HH heads Sex
|
-134.712
|
12.771
|
-10.548
|
.000*
|
The religion of HH heads
|
221.591
|
7.412
|
29.898
|
.000*
|
Knowledge extent of climate change
|
-25.802
|
6.605
|
-3.906
|
.000*
|
Access to climate change information
|
215.850
|
26.044
|
8.288
|
.398 ns
|
Use of any insecticide or pesticide
|
-93.624
|
21.986
|
-4.258
|
.036*
|
Use of improved seed varieties of crops
|
326.631
|
15.090
|
21.646
|
.000*
|
Marital status of the HH heads
|
-28.970
|
10.377
|
-2.792
|
.435 ns
|
The highest-grade level of HHLs completed
|
-68.180
|
1.345
|
-50.688
|
.000*
|
Age of the HH heads
|
63.814
|
5.189
|
12.299
|
.000*
|
Family size
|
49.779
|
5.691
|
8.746
|
.000*
|
Hypothesis test of the multiple linear regression model.
Analysis via the multiple linear regression model revealed that farmer agroecology type, sex, religion, knowledge of climate variability, use of chemicals, use of special seeds, highest grade level HH heads completed, age of HH heads, and family size were the significant (P<0.05) independent variables predicting the response variable impacts of climate change on crop production loss of smallholder farmers at the 5% level of significance. This implies that the nine explanatory variables have additional predictive power for predicting the response variable impacts of climate change on the crop production loss of smallholder farmers. Accordingly, farmer's AEZs, use of chemicals, farmer's knowledge of climate variability, education, and sex of the HH heads were found to be negatively significant (P<0.05) variables that predicted the response variable effects of climate change on crop production loss of smallholder farmers at the 5% level of significance.
For instance, the Ρ–values for the farmers' agroecological type (highland, midland, and lowland) and use of chemicals (insecticide/pesticide) were much lower than 0.05, which implied that there was significant evidence that the null hypothesis was accepted at the 5% level of significance. Thus, for a unit increase in the level of the farmer's agroecological zone, the amount of food crop yield loss (kg ha− 1) due to climate change decreased by 143.44 when the remaining variables were kept constant. These results implied that, compared with farmers who lived in the midland and lowland AEZs, smallholder farmers in the highland AEZs experienced a decrease in crop yield loss of 143.44 kg ha− 1. Similarly, farmer holders who used a litter of chemicals (insecticide/pesticide) on their farm for cultivation decreased the amount of crop yield loss due to climate change by 93.62 kg compared with household head farmers who did not use it at all.
Moreover, the P–values (0.00) for the farmer's rating of their knowledge extent about climate variability, education status, and sex of the HH heads were much lower than 0.05 and were found to be significant negative variables that influence the amount of crop production loss due to climate change. For example, HHs who were aware of climate change decreased the amount of crop production lost by 25.80 kg to a greater extent than did farmers who were familiar with climate change or who were not aware of climate change. The analysis also revealed that as the education status of the HH heads increased by one grade, the amount of crop yield loss decreased by 68.18 kg. Compared with female-headed HHs, male-headed HHs likely decreased the amount of crop production loss by 134.71 kg.
However, the age of the HHs, religion, family size of the HHs, and use of improved seed varieties were found to be positive significant factors affecting the crop yield loss of the smallholder farmer. Thus, the study results revealed that the amount of crop production loss of the smallholder farmers increased by 63.81 kg as the age of the HHs increased by one year. The amount of crop production loss increased by 49.78 kg as the household size increased by one person. Similarly, the religious affiliation of HH heads increases the impact of climate variability on crop damage to smallholder farmer communities by 221.59 kg units when the remaining variables are kept constant. Farmholders who used improved seeds increased the impact of climate variability on the livelihoods of smallholder farmer communities by 326.63 kg compared with household head farmers who did not use special seed varieties.