INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue X October 2025  
Climate Dynamics, Fertilizer use, and Cassava Output in Nigeria: A  
Four-Decade Trend Analysis (1980 – 2023)  
Enoch, O.C1. Echebiri, R.N2; Amusa T.A2; Anyaim, K.H1; Aigbokie S.O3; Enoch, J.U2 and Nwankwo,  
E.N4  
1Department of Agricultural Economics, Federal University of Technology, Imo State,  
2Department of Agricultural and Vocational Education, Michael Okpara University of Agriculture  
3Department of Agricultural Economics, Gregory University, Uturu  
4National Horticultural Research Institute, Ibadan  
DOI: https://dx.doi.org/10.51244/IJRSI.2025.1210000327  
Received: 02 November 2025; Accepted: 08 November 2025; Published: 21 November 2025  
ABSTRACT  
This study investigated the trends in climatic variables, fertilizer use, and cassava production in Nigeria from  
1980 to 2023, utilizing exponential trend analysis on secondary data sourced from the Food and Agriculture  
Organization (FAO) statistics, the World Bank database, the National Bureau of Statistics (NBS), and the  
Nigerian Meteorological Agency (NiMet). Results indicated a slight but significant decline in rainfall (β = -  
0.0021, p < 0.01) and cassava yield (β = -0.0094, p < 0.01), alongside significant temperature increases (β =  
0.0037, p < 0.01), relative humidity (β = 0.0027, p < 0.01), solar radiation (β = 0.0154, p < 0.01), cultivated land  
area for cassava (β = 0.0052, p < 0.01), and labour force involved in cassava production (β = 0.2599, p < 0.01).  
Fertilizer use showed a negative but statistically insignificant trend (β = -0.0392, p > 0.05). These findings  
suggest that, despite increasing land and labour inputs, as well as expanding solar radiation and humidity, cassava  
yields are declining, likely due to decreasing rainfall, rising temperatures, and inadequate fertilizer application.  
The study concluded that climate variability, coupled with limited technological adoption as exemplified in low  
fertilizer use, threatens cassava productivity in Nigeria. It recommends urgent investment in climate-smart  
agricultural practices, enhanced access to fertilizers, and the promotion of drought- and heat-tolerant cassava  
varieties to bolster resilience and sustain production.  
Keywords: Cassava output, climate variability, fertilizer use, time-series analysis, Nigeria, 1980–2023  
INTRODUCTION  
The agricultural sector plays a crucial role in Nigeria’s socioeconomic system, providing employment for over  
70% of the rural population and making a significant contribution to the country's GDP and national food security  
(Adofu et al., 2010). In this sector, cassava is one of the most vital staple crops due to its adaptability, low  
production costs, and widespread consumption across the country (Ajayi, 2014; Dixon & Ssemakula, 2008).  
Nigeria remains the world’s largest cassava producer, yet the crop continues to underperform relative to its full  
potential due to climate variability, limited access to improved technologies, and other structural inefficiencies  
(Bentley et al., 2017; BlueSense, 2023).  
From 1980 to 2023, Nigeria has experienced significant changes in climate factors such as rainfall, temperature,  
relative humidity, and solar radiation, which are essential to agricultural productivity. Climate variability and  
change, evident through unpredictable rainfall, rising temperatures, and extreme weather events, have increased  
risks to farming systems, threatening sustainable cassava production (Adejuwon, 2004; Akande et al., 2017).  
Studies show that these climate changes directly impact physiological processes in cassava, including growth  
cycles, tuber development, and resistance to diseases (Alves & Setter, 2016; Agba et al., 2017).  
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Rainfall, a critical water source for crop growth, has become increasingly unpredictable in timing and  
distribution, leading to delayed planting and crop failure in rain-fed systems (Akinniran et al., 2013). Cassava,  
although relatively drought-resistant, still depends on adequate moisture for optimal yields. Similarly, increased  
average temperatures and the frequency of heat waves have implications for cassava’s photosynthetic efficiency  
and stress tolerance thresholds (Ajetombi & Abiodun, 2010; Ebele & Emodi, 2016). Relative humidity, on the  
other hand, significantly influences pest and disease dynamics, such as root rot and mosaic virus, which reduce  
yield and crop quality (Alehile, 2023).  
Solar radiation, a crucial component for photosynthesis and dry matter accumulation, has shown spatial and  
seasonal variability across Nigeria’s ecological zones, affecting cassava productivity (Alves & Setter, 2016).  
Though cassava generally thrives under high light intensity, excess solar radiation in combination with moisture  
stress can lead to oxidative damage, reduced stomatal conductance, and suboptimal tuberization (Chikezie et al.,  
2015).  
Besides climatic factors, the importance of technology, especially inorganic fertilizer use, cannot be overstated.  
Fertilizer application is crucial for maintaining soil fertility and increasing cassava yields, particularly as  
continuous cultivation depletes essential nutrients (Biratu, 2018). However, the trend in fertilizer usage in  
Nigeria remains inconsistent due to issues related to cost, distribution, and farmers’ awareness (Amanchukwu et  
al., 2015; Anabaraonye, 2019). Despite government programs promoting fertilizer subsidies, adoption levels  
stay low, limiting the sector's ability to offset climate-related yield losses (Siregar et al., 2017).  
Furthermore, the combined influence of technology and climate factors creates complex interactions that affect  
cassava productivity. For example, while improved fertilizer use can mitigate the adverse effects of poor soils,  
its effectiveness diminishes under erratic rainfall or drought conditions. Similarly, innovations in planting  
methods and crop management practices are only beneficial when they align with prevailing agro-climatic  
realities (Asare et al., 2017; Amanchukwu et al., 2015).  
Cassava’s performance over the past four decades can be viewed through the dual lens of climate change and  
technological adaptation. Understanding how these factors have evolved is essential for developing effective  
policy measures and guiding future research efforts (Agba et al., 2017; Akomolafe et al., 2018). This is  
particularly crucial given global climate models that predict increased temperatures and rainfall variability in  
West Africa, which have significant implications for food security (BNRCC, 2011; Butu et al., 2023).  
Therefore, this study examines long-term trends in key climatic parameters (rainfall, temperature, relative  
humidity, and solar radiation), fertilizer use as an indicator of agricultural technology, and cassava output in  
Nigeria from 1980 to 2023. By analyzing how these variables change over time and relate to each other, the  
research aims to offer insights into the factors driving cassava productivity and to guide climate-smart and  
technology-based agricultural planning. This evidence is vital for supporting Nigeria’s adaptation efforts and  
building resilience in its cassava supply chain in the face of an increasingly uncertain climate (Adejuwon, 2004;  
Alehile, 2023; Dioha & Emodi, 2018).  
MATERIALS AND METHODS  
The study was conducted in Nigeria. It is located between the Sahel region to the north and the Gulf of Guinea  
to the south in the Atlantic Ocean. Nigeria shares borders with Niger to the North, Chad to the North-East,  
Cameroon to the East, and Benin to the West. The country consists of thirty-six (36) States, a Federal Capital  
Territory (FCT), Abuja, and covers a land area of 923,768 km², with 13.000 km of water borders (NBS, 2023).  
The country lies between latitudes 3°15' and 13°30' N and longitudes 2°15' and 15°00' E of the Greenwich  
Meridian (Federal Ministry of Environment, 2020). Nigeria has an estimated population of 214,741,311 as of  
the second quarter of 2023, with an annual growth rate of 2.5% (World Bank, 2023).  
Nigerian agricultural sector have employed more than 36% of the Nigerian labour force, a feat which ranked the  
sector as the largest employer of labour in the country (Nigeria Bureau of Statistics, 2024). Agricultural output  
acts as a resource for many processing industries and as a means of foreign exchange earnings for the country.  
Nigeria's agricultural sector is not immune to the impact of climate change due to dependence on a rain-fed  
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agricultural production system, and a climate outcome reducing output could severely affect the contribution of  
the sector to the gross domestic product (GDP) (Alehile, 2023).  
Food and Agriculture Organization (FAO), World Bank database, National Bureau of Statistics (NBS), and the  
Nigerian Meteorological Agency (NiMet) data were collected which consisted fertilizer usage rates, cassava  
output, and climatic variables (rainfall, temperature, solar radiation, and relative humidity) for the study period.  
Data were analyzed using the log-linear trend equation modeled following Onyenweaku (2004).  
Model Specification  
The log-linear trend equation for this study was and represented as follows:  
ln (Yt)= α+βt+ϵt  
- - - Equation (1.0)  
where;  
ln (Yt) = natural log of the variable of interest at time  
α = intercept (baseline log-level of the variable)  
β = slope or trend coefficient (average growth rate over time)  
t = time in years (from 1980 to 2023)  
ϵt = error term (captures shocks or deviations)  
Each variable will be estimated separately as thus,  
ln (Raint) = α1 + β1t + µ1t  
- - - Equation (1.1)  
- - - Equation (1.2)  
- - - Equation (1.3)  
- - - Equation (1.4)  
- - - Equation (1.5)  
- - - Equation (1.6)  
ln (Tempt) = α2 + β2t + µ2t  
ln (RHt) = α3 + β3t + µ3t  
ln (SRt) = α4 + β4t + µ4t  
ln (Techt) = α5 + β5t + µ5t  
ln (CASSAVAt) = α6 + β6t + µ6t  
ln (LABOURt)= α7 + β7t + µ7t  
--- Equation (1.7)  
--- Equation (1.8)  
ln (AREAt)= α8 + β8t + µ8t  
Where,  
RAINt = Average annual rainfall in millimeters in period t.  
TEMPt = Average annual temperature in centigrade in period t.’  
RHUMt = Relative humidity in (%) in period t.  
SRADt = Annual average solar radiation (e.g., MJ/m²/day) in period t.  
RFUCPt = Total quantity of fertilizer used for cassava production (metric tons or kg/ha) for the period, t  
CASSAVAt = Annual cassava production (metric tons) in year t,  
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LABOURt = Labour force in man-days in year t,  
AREAt = area of land in hectare in year t,  
α1 – α8 = the constants in the regression line.  
β1–β8= the trend coefficient.  
t = trend variable measured in years (t = 1, 2, 3...44)  
µt = the error term.  
Multivariate Regression  
The functional form of the multivariate regression model can be expressed as:  
Cassava Yield =  
+
1Rainfall + 2Temperature + 3Relative Humidity + 4Fertilizer Usage +  
0
5Area of Land + 6Solar Radiation + 7Labour Force +  
-
-
-
-
1.9  
Where:  
Cassava Yield = Cassava yield in year (tons/ha or appropriate unit)  
Rainfall = Total rainfall in year (mm)  
Temperature = Mean annual temperature in year (°C)  
Relative Humidity = Average relative humidity in year (%)  
Fertilizer Usage = Fertilizer application in year (kg/ha)  
Area of Land = Area of land cultivated for cassava in year (ha)  
Solar Radiation = Average solar radiation in year (MJ/m²/day or equivalent unit)  
Labour Force = Labor input in cassava production in year (number of workers or man-days)  
0= Intercept term  
,
2, . . . , 7= Coefficients representing the marginal effect of each independent variable on cassava yield  
1
= Error term capturing all other factors affecting cassava yield not included in the model  
RESULT AND DISCUSSION  
Table 1: Estimated exponential trend equations for rainfall, temperature, relative humidity, cassava yield,  
fertilizer usage, area of land, solar radiation, and labour force in Nigeria (1980-2023).  
Dependent Variable  
Rainfall  
β₀  
β₁  
r²  
Adj. r²  
0.4070  
0.4608  
0.9986  
F-ratio  
8.64  
8.0016***  
3.2140***  
4.1057***  
-0.0021  
0.0037***  
0.0027***  
0.4366  
0.4901  
0.9987  
Temperature  
9.86  
Relative Humidity  
31756.93  
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INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
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Cassava Yield  
Fertilizer  
9.3744***  
11.5728***  
10.9460***  
1.5296***  
1.6172  
-0.0094***  
-0.0392  
0.6528  
0.2823  
0.9093  
0.9923  
0.5861  
0.6247  
0.2604  
0.9072  
0.9921  
0.5762  
19.84  
3.77  
Area of Land  
Solar Radiation  
Labour Force  
0.0052***  
0.0154***  
0.2599***  
421.31  
5404.17  
59.46  
Source: Computed from time-series data, 1980-2023. Note: *** implies statistically significant at 0.01  
probability levels, respectively. Figures in brackets are t-values  
Rainfall exhibited a slight but negative growth trend over the study period, with a β₁ coefficient of -0.0021 and  
a coefficient of determination (R²) of 0.4366. Although the trend is statistically significant at the 1% level, the  
negative coefficient suggests a gradual decrease in rainfall over time in Nigeria between 1980 and 2023. This  
implies that approximately 43.66% of the variation in annual rainfall is explained by the time trend, as  
substantiated by the F-ratio of 8.64. This declining trend in rainfall aligns with the growing body of evidence  
highlighting the effects of climate change in West Africa, particularly in Nigeria. According to Haider (2019),  
the country has experienced significant shifts in rainfall patterns, with shorter wet seasons and increased  
unpredictability, a phenomenon that exacerbates the vulnerability of rain fed agricultural systems such as cassava  
cultivation. Reduced rainfall threatens soil moisture retention, delays planting, and increases the risk of crop  
failure, especially in regions with poor irrigation infrastructure. The implication is clear: unless adaptive  
strategies such as efficient irrigation systems, water harvesting technologies, and drought-tolerant cassava  
varieties are adopted, the declining rainfall trend could undermine long-term cassava productivity and food  
security in Nigeria (IPCC, 2013; Jarvis et al., 2020).  
Graphical Presentation of Trends of Annual Rainfall in Nigeria (1980–2023)  
The trend in annual rainfall in Nigeria between 1980 and 2023 is shown in Figure 1.1  
Average annual rainfall (mm)  
14,000.00  
12,000.00  
10,000.00  
8,000.00  
6,000.00  
4,000.00  
2,000.00  
-
Year  
Figure 1.1 Trend in annual rainfall in Nigeria between 1980 and 2023.  
Temperature recorded a statistically significant positive growth trend over the reference period, with a β₁  
coefficient of 0.0037*** and an R² value of 0.4901, indicating that 49.01% of the temperature variation is  
explained by time. The F-ratio of 9.86 confirms the model’s validity. This consistent rise in average temperature  
mirrors broader global warming trends, which are expected to continue in the coming decades (IPCC, 2007).  
Rising temperatures can have both beneficial and detrimental effects on cassava. On the one hand, moderate  
warming may enhance photosynthesis and root development; on the other hand, excessive heat can lead to  
evapotranspiration stress, impaired tuberization, and shortened growing cycles. According to Hassnain Shah et  
al. (2021), temperature increases are one of the most critical climate risks to agriculture, particularly when not  
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balanced with adequate water availability. As Nigeria continues to experience warming, farmers may need to  
adapt by shifting planting dates, adopting heat-resistant cultivars, and improving soil organic matter to enhance  
moisture retention. Failure to adapt could diminish the suitability of cassava cultivation in traditional regions, as  
noted by Jarvis et al. (2020).  
Graphical presentation of trends of annual temperature in Nigeria from 1980 - 2023.  
The trend in annual temperature in Nigeria between 1980 and 2023 is shown in Figure 1.2  
Average annual temperature  
35.00  
30.00  
25.00  
20.00  
15.00  
10.00  
5.00  
-
Year  
Figure 1.2 Trend in annual temperature in Nigeria between 1980 and 2023.  
Relative Humidity exhibited an exceptionally strong and statistically significant positive trend, with a β₁  
coefficient of 0.0027*** and a near-perfect R² value of 0.9987. The F-ratio of 31,756.93 reinforces the high  
precision of the model. This trend indicates that relative humidity has increased almost linearly over the past  
four decades in Nigeria. Increased atmospheric moisture may benefit cassava in water-scarce areas by reducing  
plant stress; however, excessively high humidity levels can also promote the spread of fungal and bacterial  
diseases. This is particularly concerning in storage and post-harvest stages, where high humidity can result in  
rapid spoilage and economic losses. Haider (2019) and Hershey et al. (2001) both noted that changes in humidity  
levels, combined with rainfall and temperature fluctuations, require renewed focus on integrated disease and pest  
management practices. Therefore, while the rising humidity trend may offer short-term physiological benefits to  
cassava plants, it poses long-term risks that call for improved drying, processing, and storage innovations.  
Graphical presentation of trends of relative humidity in Nigeria from 1980 - 2023.  
The trend in relative humidity in Nigeria between 1980 and 2023 is shown in Figure 1.3  
RHUMt  
70.00  
68.00  
66.00  
64.00  
62.00  
60.00  
58.00  
56.00  
Year  
Figure 1.3 Trend in relative humidity in Nigeria between 1980 and 2023.  
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Cassava Yield, the principal focus of the study, displayed a worrisome negative and statistically significant  
trend, with a β₁ coefficient of -0.0094*** and an R² of 0.6528. This means that 65.28% of the variation in cassava  
yield can be attributed to the passage of time. Despite advancements in research, policy interventions, and  
increased labour and land allocation, yields have declined steadily. The F-ratio of 19.84 validates the strength of  
the model. This outcome raises critical questions about the sustainability of cassava production systems in  
Nigeria. Yield declines may result from a combination of climate stressors, declining rainfall, increasing  
temperatures, and soil nutrient depletion as well as socio-economic constraints such as poor access to quality  
inputs, limited mechanization, and weak extension services. Howeler et al. (2006) found similar yield stagnation  
in Asian cassava systems due to declining soil fertility and suboptimal agronomic practices. These findings are  
echoed by Ivan et al. (2017), who emphasized that nutrient imbalances and delayed adoption of improved  
varieties can lead to sharp declines in productivity. The situation calls for urgent investment in research, climate-  
resilient technologies, and farmer training to reverse the downward trend in yield.  
Graphical presentation of trends of cassava (fresh yield) in Nigeria from 1980 - 2023.  
The trend in cassava (fresh yield) in Nigeria between 1980 and 2023 is shown in Figure 1.4  
Cassava, fresh Yield (kg/ha)  
14000  
12000  
10000  
8000  
6000  
4000  
2000  
0
Year  
Figure 1.4 Trend in cassava (fresh yield) in Nigeria between 1980 and 2023.  
Fertilizer Use showed a negative trend with a β₁ coefficient of -0.0392, but it was not statistically significant,  
and the model’s R² was relatively low at 0.2823. This indicates that only 28.23% of the variation in fertilizer use  
is explained by the time trend variable, with an F-ratio of 3.77. The non-significant downward trend suggests  
weak, inconsistent, or declining use of fertilizers over the years. This could be attributed to high input costs,  
subsidy inefficiencies, poor farmer education, or declining government investment in fertilizer distribution  
systems. Ihtisham et al. (2020) and IFAD (2001) both highlighted that inadequate access to fertilizers and  
inappropriate application practices remain major barriers to productivity in low-income countries. Given the  
central role of balanced nutrient supply in boosting cassava yield—particularly under climate stress—this finding  
points to a critical gap in Nigeria’s agricultural policy. Scaling up fertilizer access through subsidy reform, agro-  
dealer networks, and extension support is essential for long-term yield sustainability.  
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Graphical presentation of trends of cumulative fertilizer usage in Nigeria from 1980 - 2023.  
The trend in cumulative fertilizer usage in Nigeria between 1980 and 2023 is shown in Figure 1.5  
cummulative Fertilizers (t)  
160000  
140000  
120000  
100000  
80000  
60000  
40000  
20000  
0
Year  
Figure 1.5 Trend in cumulative fertilizer usage in Nigeria between 1980 and 2023.  
Area of Land Cultivated for cassava showed a strong, positive, and statistically significant growth trend, with  
a β₁ coefficient of 0.0052*** and an R² of 0.9093, indicating that over 90% of the variation in land area is  
explained by the time trend. The F-ratio of 421.31 supports the reliability of the model. This suggests that  
Nigerian farmers have continually expanded the area cultivated with cassava, likely as a response to falling  
yields in an attempt to maintain or increase total production. While this land extensification strategy may sustain  
short-term output, it raises significant environmental and economic concerns. Expansion into marginal lands can  
lead to deforestation, land degradation, and reduced ecosystem services (Howeler et al., 2017; Haider, 2019).  
The finding highlights the need to transition from extensive to intensive farming practices, emphasizing input  
optimization, mechanization, and precision agriculture to enhance land productivity without expanding the farm  
frontier.  
Graphical presentation of trends of the area of land harvested in Nigeria from 1980 - 2023.  
The trend in the area of land harvested in Nigeria between 1980 and 2023 is shown in Figure 1.6  
68000  
66000  
64000  
62000  
60000  
58000  
56000  
54000  
52000  
50000  
YEAR  
Figure 1.6 Trend in area of land harvested in Nigeria between 1980 and 2023.  
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Solar Radiation exhibited a strong and significant positive trend, with a β₁ coefficient of 0.0154*** and an R²  
of 0.9923. The exceptionally high F-ratio (5,404.17) indicates the robustness of the model. Increased solar  
radiation suggests that crops now receive more sunlight, which can enhance photosynthesis and potentially  
increase biomass under ideal conditions. However, in the presence of heat stress and declining rainfall, excessive  
solar radiation may aggravate water stress and reduce cassava productivity (Ibayashi et al., 2016). Furthermore,  
increased solar exposure without proper canopy coverage may lead to heat-induced chlorosis, particularly in  
young plants. Therefore, while solar radiation is generally beneficial, its interaction with other climatic factors  
must be carefully monitored and managed through shading techniques, mulching, and moisture conservation  
practices.  
Graphical presentation of trends of solar radiation in Nigeria from 1980 - 2023.  
The trend in solar radiationin Nigeria between 1980 and 2023 is shown in Figure 1.7  
Solar Radiation (kWh/m²/day)  
10.00  
9.00  
8.00  
7.00  
6.00  
5.00  
4.00  
3.00  
2.00  
1.00  
-
Year  
Figure 1.7 Trend in solar radiation in Nigeria between 1980 and 2023.  
Labour Force showed a positive and statistically significant trend, with a β₁ coefficient of 0.2599*** and an R²  
of 0.5861, meaning that 58.61% of the variation in the agricultural labour force is explained by time. The F-ratio  
of 59.46 supports the statistical soundness of the model. This trend reflects a growing labour pool in cassava  
farming, likely driven by rural population growth and limited off-farm employment opportunities. However, the  
corresponding drop in yield suggests that labour productivity has not increased proportionally. This calls to  
question the quality, training, and efficiency of labour utilized. Ismaila et al. (2010) emphasize that while labor  
availability is high in rural Nigeria, its productivity remains constrained by outdated tools, limited training, and  
a lack of mechanization. Addressing this issue requires not only capacity-building programs but also investments  
in labor-saving technologies that can improve efficiency and reduce drudgery.  
Graphical presentation of trends of the Labour force in Nigeria from 1980 - 2023.  
The trend in the Labour force in Nigeria between 1980 and 2023 is shown in Figure 1.8  
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30000  
25000  
20000  
15000  
10000  
5000  
0
YEAR  
Figure 1.8 Trend in the Labour force in Nigeria between 1980 and 2023.  
Table 2: Multivariate Regression Results for effect of climate variables on Cassava Yield in Nigeria (1980–  
2023)  
Variable  
Coefficient (β)  
2.315  
Std. Error  
1.024  
t-Statistic  
2.26**  
2.76***  
-1.86*  
p-Value  
0.029  
0.008  
0.067  
0.041  
0.014  
0.000  
0.029  
0.012  
Intercept  
Rainfall  
0.0058  
-0.0134  
0.0021  
0.0875  
0.0453  
0.0219  
0.1126  
0.812  
0.0021  
0.0072  
0.0010  
0.0346  
0.0081  
0.0097  
0.0435  
Temperature  
Relative Humidity  
Fertilizer Usage  
Area of Land  
Solar Radiation  
Labour Force  
R²  
2.10**  
2.53**  
5.59***  
2.26**  
2.59**  
Adjusted R²  
F-statistic  
0.794  
45.36  
<0.001  
Durbin-Watson  
1.92  
Source: Computed from time-series data, 1980-2023. Note: *** Significant at 1%, ** Significant at  
5%,*significant at 10%  
The multivariate regression results indicate that both climatic variables and farm inputs significantly influence  
cassava yield in Nigeria over the period 1980–2023. The model as a whole is robust, explaining 81.2% of the  
variation in cassava yield (R² = 0.812) with an adjusted R² of 0.794. The F-statistic of 45.36 (p < 0.001) confirms  
overall model significance, while the Durbin-Watson statistic of 1.92 indicates minimal autocorrelation in the  
residuals, supporting the reliability of the estimates. The multivariate regression results show that rainfall has a  
positive coefficient of 0.0058, significant at the 1% level (p = 0.008), indicating that higher rainfall is associated  
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with increased cassava yield. This finding aligns with Ebele and Emodi (2016), who noted that rainfall is a key  
determinant of agricultural productivity in Nigeria, as adequate moisture supports crop growth and tuber  
development. Relative humidity also has a positive effect (β = 0.0021, p = 0.041, significant at 5%), suggesting  
that increased humidity contributes to higher cassava yields. This supports Ebele and Emodi’s (2016)  
observation that favorable moisture conditions, including humidity, are critical for crop performance, especially  
in tropical climates where cassava is grown. Temperature shows a negative effect on cassava yield (β = -0.0134,  
p = 0.067, marginally significant at 10%), indicating that higher temperatures may slightly reduce productivity.  
This is consistent with Dioha and Emodi (2018), who highlighted that rising temperatures under climate change  
can stress crops and reduce their efficiency, emphasizing the vulnerability of staple crops like cassava to warming  
conditions. Fertilizer usage positively influences cassava yield (β = 0.0875, p = 0.014, significant at 5%),  
suggesting that increased fertilizer application enhances production. This finding aligns with Dixon and  
Ssemakula (2008) and Dixon et al. (2010), who emphasized that appropriate nutrient management, including  
fertilizer application, is essential for improving cassava productivity in Sub-Saharan Africa. The area of land  
cultivated has a strong positive effect (β = 0.0453, p < 0.001, significant at 1%), indicating that expanding land  
for cassava cultivation directly increases output. This observation supports Dixon and Ssemakula (2008), who  
highlighted that adequate land allocation is crucial for achieving higher yields, particularly in regions where  
cassava is a staple crop. Solar radiation also positively affects yield (β = 0.0219, p = 0.029, significant at 5%),  
reflecting the importance of sunlight for photosynthesis and biomass accumulation. This finding is consistent  
with Dixon et al. (2010), who noted that adequate light exposure is essential for tuber growth in improved cassava  
varieties. Finally, the labor force has a positive and significant effect on cassava yield (β = 0.1126, p = 0.012,  
significant at 5%), indicating that greater labor input enhances productivity. This agrees with Dixon and  
Ssemakula (2008), who stressed that sufficient labor is critical for executing proper agronomic practices and  
ensuring high yields.  
RECOMMENDATIONS  
1. Implement climate-smart agricultural strategies such as efficient irrigation, water conservation, and soil  
moisture retention techniques to cushion against rainfall variability and drought conditions.  
2. Promote the development and dissemination of drought-tolerant, heat-resistant, and disease-resistant cassava  
varieties responsive to shifting climatic conditions.  
3. Enhance fertilizer access through effective subsidy reforms and farmer education initiatives to ensure efficient  
nutrient application.  
4. Advocate for sustainable intensification by transitioning from expansive land-use practices to intensive  
farming methods using mechanization and precision agriculture.  
5. Invest in labour efficiency programs through training in modern farming techniques and labour-saving  
technologies aimed at increasing productivity.  
6. Strengthen integrated pest and disease management measures by developing better post-harvest standards and  
innovations that mitigate losses from fluctuating humidity and disease incidents.  
7. Support ongoing research efforts to further understand climate impacts, farmer behaviour, and adaptation  
technologies, coupled with policies that prioritize sustainable cassava production in Nigeria.  
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