ANALYSIS of CLIMATE CHANGE EFFECTS on RICE OUTPUT in EBONYI STATE, NIGERIA: 1990- 2015 Nte I. Nwali. and Frank N. Okoro Departme
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Conference Proceedings of The 18" Annual National Co,iferen<;:e ofThe Nigerian Association OfAgricultural Economists Held At Federal University ofAgriculture, Abeokuta, Nigeria 16" - 19th October; 2017, ANALYSIS OF CLIMATE CHANGE EFFECTS ON RICE OUTPUT IN EBONYI STATE, NIGERIA: 1990- 2015 Nte I. Nwali. and Frank N. Okoro Department of Agricultural Economics, Management and Extension, Ebonyi State University Abakaliki, Nigeria. *CORRESPONDENCE E-MAIL: franknna@yahoo,uk Telephone No. +2348065098290 ABSTRACT The study analysed the effects 'of climate change on rice output -in Ebonyi state. The study was necessitated by the fluctuating output of rice that m~y have not kept pace with population growth and also to fill the gap in the knowledge of effects of climate change on rice output. The objectives of the study were achieved using secondary data collected from EBADEP and NIMET from 1990-2015 where data on rice output and climate variables were collected respectively. Line graph and Cobb-Douglas functional form were used to analyse the data collected while F-test was used for test hypothesis. Results showed that onset and cessation of rainfall was in the month of May and November, respectively. Results also indicated that sixty seven percent (67%) of the fluctuations in the output of rice were accounted for by the explanatory variables included in the model. Specifically, rainfall (- 1.555) adversely affected rice output and was also revealed by the negative constant (-15 .333). However, evapo transpiration rate (2.027) and solar radiation (9.652) encouraged rice yields. Again the tested hypothesis affirmed that changes in climate variables adversely affected rice output in the area. The study therefore is of the opinion that climate change effects deleteriously affected the output of rice in Ebonyi state. However, the endowment of rivers in the state should be harnessed to provide irrigation agriculture to cushion the effects of extreme events of climate variables and farmers should change their time of planting to suit the changes in the climate variables. KEYWORDS: Ebonyi, output, evapo-transpiration, rainfall, cessation sunshine INTRODUCTION Weather is the atmospheric condition of any location at a particular period. Climate on the other hand is the average weather condition of an area over a period of time say 30 years. This period is a period during which a number of changes in the variables that determine the predominant climatic pattern in the regions are known. The variables include rainfall, temperature, sunshine intensity, evaporation rate, relative humidity, atmospheric pressure, cloud cover, snow, dew, frost and wind. Generally, climate change is a change in the state of the climate that can be identified, for example by using statistical test by changes in the mean and or the variability of its properties and that persist for an extended period, typically decades or longer. This is occasioned by global weather patterns like rises in temperature overtime, rainfall fluctuations and storm activities evolved from· the potential consequences of the greenhouse effects and continue deforestation (Ayoade, 2006; IPCC, 2007). The amount of rainfall, its intensity and distribution are characteristics affected by climate change and the uncertainties surrounding global warm,ing have reflected in diverse studies on climate change in Nigeria (Rao, 2006, Adefolalu, 2006). The two major factors affecting crop yields and productivity are weather condition and soil nutrients (Onyekwelu et al., 2006), thus to improve the production of any crop, it is rationale to understand the average weather conditions of such area. Climate change is one of the most serious threats to Nigeria agricultural sector and food security, because of its sensitivity and vulnerability to high ambient temperature ·and rainfall Coonference Proceedings of The 1811, Annual National Conference of the Nigeria Association Of The Nigerian Agricultural 591 Economists Held at Federal University of Agriculture, Abeokuta, Nigeria 16'"- 1911, October, 2017 • Analysis Of Climate Change Effects On Rice Output In Ebonyi State, Nigeria: 1990- 2015 fluctuations. For instance, higher temperature lowers the yields of the desirable crops, while encouraging weeds and pests proliferation and changes in precipitation patterns increase the likelihood of short-run crop failure and long-run production declines, thus its variability create a huge challenge for food production (Claire, 2009). Climate change drive extreme weather events such as floods and the increased risks of drought, crop yields losses and are affecting all economic sectors to some degrees but the agricultural sector is the most vulnerable as agricultural production remains very dependent on climate resources (Ajokporise, 2011; Ayandele et al, 2010). In Ebonyi state, the low output of rice farmers may be attributed to high incidence of pests, weeds and diseases; and extreme events of the climate in the form of droughts, flooding and its consequences. However, in Ebonyi State, and Nigeria in general, there is increase in rice production but the current level of production may not still meet the estimated national requirement of 5 million metric tons of rice due to the incidence of climate change and increase in population that may have not kept pace with food production (Onyenweaku et al, 2000; Oselebe, 2013). Several research works have been conducted on climate change and crop production but little or none seem to have been done on climate change and rice output in Ebonyi state and as such the research tends to fill the gap in knowledge of climate change effects and rice output. Then, what are the cause of low output of rice in Ebonyi State? Are there changes in the onset and cessation of rainfall in area? The broad objective of the study therefore is to analyse the effects of climate change on the output of rice in Ebonyi state, Nigeria: 1990-2015. Specifically, the study sets to: determine onset and cessation of rainfall in the area and analyse the relationship between rice output and climate variables in the area. Hypothesis: the hypothesis which stated that climate variables have no significant effects on the output of rice in Ebonyi state was tested by this study. Materials and Methods Study Arca: the study was carried out in Ebonyi state. ____ } According to (NPC, 2006), Ebonyi state has a population of about 2.1 million people spread within the thirteen (13) local government areas which occupied a total land mass of approximately 5,932 square kilometers. The state had made name in the area of rice production hence the popular Abakaliki rice and establishment ultr,a-modern rice mills in each of the zones in the state. The state is endowed naturally with rivers and arable land for different agricultural activities. Coonfcrencc Proceedings of The 18'" Annual Natlpnal Conference of the Nigeria Association Of The Nigerian Agricultural 592 Economists Held at Federal University of Agriculture, Abcokuta, Nigeria J6' h - 19'" October, 2017. Analysis Of Climate Change Effects On Rice Output In Ebonyi State, Nigeria: 1990- 2015 Data Source: the data used for the study were sourced from Ebonyi state Agricultural Development Programme (EBADEP) reports on agricultural production survey ( data on rice output) -and data on climate variables were collected from Nigeria Meteorological Agency (NIMET), Akanu-lbiam International Airport Enugu for the period under study. Analytical Techniques: the data for the study were analysed using line graph. The line graph was used to identify onset and cessation of rainfall in the area. The regression model related output of rice in kilogram per hectare to meteorological data (rainfall, temperature maximum, relative humidity, solar radiation and evaporation rate) was used to analyse the effects of climate change on output of rice in the area. F-test was used for test of hypothesis. The regression equation explicitly states thus: Cobb-Douglas Functional Form logYit = Po +pi!ogRt +P2logRht +p3logSht +p4logEpt +PslogTt + et-----------------------1 Where: Y = Yields of rice (t/ha), R = Rainfall annual average (mm), Rh= Relative humidity annual average(%), Sh= Sunshine hours annual average (hrs), Ep = Evaporation rate annual average (mm), T=Temperature annual average (0 C), et=Random disturbances, i = 1, 2, 3, --- n periods, p0,= Intercept, P1 - Ps = Parameter estimates RESULTS AND DISCUSSION Determination of Onset and Cessation of Wet Season in the Study Area The onset and cessation of wet season in the area was determined using moisture budget. This was obtained by plotting the graph of precipitation against evaporation rates within the period under study. This relationship was presented in Figure 1. Coonference Proceedings of The 18th Annual National Conference of the Nigeria Association Of The Nigerian Agricultural 593 th h Economists Held at Federal University of Agriculture, Abeokuta, Nigeria 16 - l9' October, 2017. Analysis Of Climate Change Effects On Rice Output In Ebonyi State, Nigeria: 1990- 2015 Figure 1: Moisture Budget Showing Onset and Cessation of Wet Seasom -+-Rainfall E(mm) -Evapo E (mm) 300 ~·-~-~--..---~-~-~--.----r----.---~---.-~ 1 9 8 7 6 e .§. ...QI 5 ..IU C 0 4 :;::: ..IU a.0 i IU 3 w> 2 r 1 I 0 +---i----+--+----t---+-----,1----+----t-----+- JAN FEB MAR APR MAY JU JLY AUG SEPT OCT NOV DEC Months From Figure 1, -precipitation (PE) is less than evapo-transpiration rate (ET) i.e., (PE<ET) from the months of January to May which implied a drought condition. The point of intersection of precipitation and evapo-transpiration rate (PE=ET) defined the onset of wet season in the area. This showed that wet season onset in the area was in late May. The two peaks of the graph showed the bimodal rainfall pattern in the area. The depression or trough indicated the popular August break witnessed in the area. The next equilibrium condition (PE=ET) seen in the month ofNovember revealed the cessation of wet season in the study area. Therefore, -there was late onset of wet season and early 9essation of wet season as observed in the Figure 1.