Extreme climatic conditions and effects on cropping activities at a farm settlement in southwestern Nigeria

Mitigating against the impact of extreme climatic conditions is a major concern for many communities in developing countries, especially in the sub-Saharan Africa. This study examined the occurrence of extreme climatic elements and coping strategies of smallholders in a farm community in Nigeria, as well as perception stakeholders in the area on the impact of extreme climatic conditions. Data used were responses of 24 purposively stakeholders and 35 years’ daily rainfall, temperature and wind speed data. Results showed that area experienced rainfall uctuations as well as temperature increase which were associated with poor germination, impaired of crops growth, alteration of quality harvests and lowered crop productivity in the area. Coping strategies varied with socio-economic differences among the farmers; with the relatively wealthy farmers practicing preventive methods while poor farmers embraced reactive strategies like changing methods of cultivation and praying. The study concluded that food security in the area as typical of many farm communities in the region, will benet signicantly from local knowledge of the farmers.


Introduction
Extreme climate conditions are a deviation from the norms (average climatic conditions), which are capable of upsetting numerous essential environmental parameters including interference to water balance and air temperature balance (Odekunle, 2004). Extreme climate conditions are phenomenon that may not been observed in an area for certain periods of time which may have occurred by climate change and climate variability. Extreme climate conditions can initiate dangerous conditions including oods, droughts, dry spell, typhoons and heavy snow. Although extreme climate condition may span for short period of time, but they can impact both environmental and agricultural processes signi cantly. In farming, situations like heavy rainfall within a limited period of time, dry spells within developing seasons when some crops require water to be available at eld capacity and heavy downpours at periods when crops need a dry spell are termed extreme events (Maracchi et al., 2005). The events are typically unpredicted and non-seasonal but the damage can be enormous (IPCC, 2007). It is a universal problem, but with diverse levels of impacts and adaptation approaches across different societies (New et al., 2006).
In Africa, extreme climate conditions are particularly susceptible due to poor technological development, low economic strength or high poverty level, climate awareness and education as well as nancial and political will to reverse the vulnerability (Mirza, 2003). According to Hansen et al. (2001), extreme climate conditions have been attributed to occur as a result anthropogenic activity of human for better living at the expense of their impacts on the environment, extreme climate conditions have increased hazard on agricultural activities. Increase in the frequency and number of extreme conditions is usually linked to climate change due to greenhouse gases and aerosol anthropogenic emissions (Planton, 2008). Recently, extreme climate conditions have become an important issue for discussion among governments, especially as climate becomes an important subject of Sustainable Development Goal (SDG 13), awareness has increased its impact and variant coping strategies (Swart et al., 2003).
Agricultural production in the sub-Saharan Africa, which is mainly dependent on rainfall for wetness, may be rigorously compromised by uctuations and extreme climatic conditions (Thompson et al., 2010). Fischer et al. (2005) argued that extreme climate conditions will cause loss of agricultural land, shortens growing seasons, lowers yields, and consequently cause food shortage. Extreme climate in the developing countries has also been linked with increase in the frequency and prevalence of certain climate delicate diseases, especially malaria, tuberculosis and diarrhea (Guernier et al., 2004). Boko et al., (2007) reported that extreme climate conditions may add more pressure to already threatened ecosystems in the region. Studies shown that in Nigeria agricultural activities suffer from extreme climate events (e.g., Ishaya  Few of the exiting studies have reported generic results from cropping activities with community-based assessments, but further investigations have been deemed necessary from relatively less documented farm community like the present study area. The area represents farm community in the sub-Saharan Africa where plants are generally rain-fed; where consideration of weather and climate is of important concern, and where coping strategies to extreme weather conditions are reportedly low (Campbell et al., 2011).
Agriculture is an essential sector in the sub-Saharan Africa, where it employs over 80% of the population (Lobell et al., 2008). The present research area, Iyanfoworogi is a typical rural community where over 85% of the populations are small-scale farmers (Adewumi and Ujoh, 2012), and most of the farming activities are rain-fed. Studies (e.g., Cooper et al., 2008;Mongi et al., 2010;Eludoyin et al., 2017), have claimed that farming activities in the many parts of Nigeria are susceptible to the in uence of climate and weather vulnerability and many small-scale farmers have poor coping strategies. Many studies have also focused on government owned research centers, establishments and institutions (Adesina and Odekunle, 2011;Enete et al., 2011;Mustapha et al., 2012), all of which are non-representatives of the rural areas. The challenges faced by rural areas include poor coping strategies, low literate level and low crop production (Enete et al., 2011), and these may be exacerbated by extreme climatic events. Many of the rural community also lack established monitoring equipment that helps to monitor the existing climatic phenomenon and adequately predict the future. The present study area is hardly known despite its contribution to food security in the state, and this is the case of many resource centres in developing world, which according to the Friedman's core-periphery model are often characterized by degraded environment (Gu et al., 2001).
The time frame for this study is 34 years (1984 to 2018) based on availability of data. Selected Climatic data (Temperature, Rainfall and Windspeed) were daily records and was collected from the archive of Prediction of Worldwide Energy Resource (POWER) programme of the United States of America's National Aeronautics and Space Administration (NASA) data due to absence of ground-based meteorological station in the study area. The study site was chosen for the research work because it is accessible and it has good representation of the purposively selected crops (tree crops, tuber crops, leafy vegetable, and cereals) for the study. The overall aim was to examine the occurrence of extreme climate events, their impacts and people's coping strategies in rural community of the Southwestern Nigeria. Speci c objectives of the study are to examine the occurrence of extreme climate events and their attributes over the farm community, assess the impact of extreme events on crop productivity and coping strategies of the farmers with effects of the extreme events in the area.

Study Area
Iyanfoworogi, a farm community is situated in Ife East Local Government Area, Ile Ife, comprises of eight districts namely Adagba, Aganran, Agidi, Alagba, Aroko, Ayingun, Ladin, and Gidi-ogbo ( Figure 1). It is typical rural areas with over 85% are small-scale farmers. The study area was preferred due to its accessibility. The farm products including tree crops (cocoa -Theobroma cacao, kola -Cola acuminata), tuber/root crop (yam -Dioscorea rotundata, cassava -Manihot esculenta), cereal crop (maize -Zea mays), leafy vegetable (okra -Abelmoschus esculentus, vegetables; Talinum triangulare, Amaranthus hybridus, Basella alba, which are the major crops in the study area. The study area exists within the tropical rainforest designated by Koppen's climate classi cation as 'Af; characterized by small temperature range throughout the year and usually convectional storms as a result of its proximity to equatorial climate (Eludoyin et al., 2014).
The study area experiences extreme seasonal variation in monthly rainfall and also major seasonal variation in the apparent humidity. The normal hourly wind speed in the study area experiences mild seasonal variation over the course of the time. Iyanfoworogi area has average rainfall of 1,000 to 1,250 mm generally from March to October and a mean relative humidity of 75-100%. Iyanfoworogi farm community has a rising and falling landscape lie beneath by metamorphic rocks and characterized by two types of soils; deep clay soils on the upper hills and sandy soils on the lower portions, which support agriculture (Ajala and Olayiwola, 2013). The study area is one of the major collecting points for plantain, cocoa, palm oil and kernels, yams, cassava, maize, orange and kolanuts in southwestern Nigeria. The crops are cultivated for local markets and also transported by farm marketers to other neighborhood states. Iyanfoworogi inhabitants are primarily town-dwelling farmers and cocoa merchants who live averagely with minimum income of less than 1 US$ per day per household, due to unhealthy economic condition of Nigeria as a country. Most of the farmers engage in cooperative societies association and trade by-batter to battle the impact of extreme climatic variations on their livelihood. Other economic activities of the Iyanfoworogi farm community includes shing, livestock and poultry farming, hunting farming, small business enterprises and lime making. The dwellers also involved in iron-smelting which helps in the area of production of iron tools such as hoe and cutlass, which makes crop cultivation easier for farmers and helps in turn bring forth abundant harvests of food.

Data
Data were selected climatic elements and responses of farmers, farm products marketers and government agencies in the area. Climate variables were temperature, wind-speed and rainfall, whose daily records for 34 (1984 -2018) years were obtained from the database of Prediction of Worldwide Energy Resource (POWER) programme of the United State of America's National Aeronautics and Space Administration (NASA), because there is no ground-based meteorological station in the study area. Data on farm activities were collected from farmers who cultivated the components crop types (tree crop farmers, tuber/ root crop farmers, cereal farmers and leafy vegetable) in the area. Responses were sought for interview questions which were patterned along the extreme climatic cases that were revealed through the analysis of climate data. Information on impacts of extreme climatic events on the study area was obtained from the selected farmers, who were considered experienced enough to provide adequate information on the study area. The interview format was structured to allow for responses from the selected key informants inform of closeended and open-ended questions. Information was sought on extreme climate events occurrence, their impacts at different stages of crop production (land preparation, planting, tendering, harvesting) and coping strategies. Also, eight major marketers mostly traders of agricultural products from the study area were selected. Government o cers, mainly a management executive and a eld o cer of the Department of Rural and Extension Service of the Osun State Ministry of Agriculture were selected based on their knowledge on the trend of agricultural activities on the study area. In all 26 Key Informant was selected.

Data Analysis
Data were rst checked for consistency and suspects, especially in the climate data (such as those with negative value or '99', '09' etc.) were removed. Statistical Package for Social Sciences (SPSS) version 21 was used as the analysis tool to generate descriptive statistics like frequency, mean, percentage and standard deviation while boxplots analyzed to identify extreme cases of events. Simple linear regression analysis was used to test the magnitude of the relationship and in uence among dependent variable (year/time) and independent variables (climatic variables). Wavelet analysis of signals in timefrequency space into small waves or bit signals (Frick et al.,1998) was used to characterize the variability in each of the selected parameters over the period of study. Wavelet analysis was achieved using Paleontological Software (PAST) version 4. Analysis of the responses of Key Informant was done with frequency distribution and Content analysis method.

General characteristics of climate
The general distribution of the selected climatic characteristics over the community, a typical rural farm community, in the Southwestern Nigeria is presented in Table 1. From Table 1, average rainfall is 4.6 mm, and this is very variable across the months in a year (136.2%). The values of the coe cient of variance indicate high variability in rainfall across the months; but with above 100% values between November and April, and in August. High rainfall variability has signi cant implication for land preparation, planting and tendering of crops (Kyei-Mensah et al., 2019). Also, peak rainfall values were higher in July-August-September (81.1mm, 95.5mm and 100.2mm, respectively) than the other months. The relatively high (95.5mm) peak rainfall value and high value of coe cient of variability (114%) suggest an occurrence of the little-dry season that typically occurs in August (August-break; Adejuwon and Odekunle, 2004). There was generally low temperature variability (2.5% -6.8%), as expected for regions in the tropics. Results of trend analysis also showed that rainfall tends to exhibit complex trend within the study area, uctuating and appearing to increase in some months while it reduced in others; while the trend was negative in March-August and October, it was positive for most of the dry months (November -February) and September. The low value (less than 1%) of the coe cient determination (R 2 ) obtained in the regression analysis suggest that the change in rainfall does not signi cantly correspond to change in year (Table 2a). For the mean temperature, most of the months (except January) experienced relative signi cant (p-value ≥ 0.05) increase, with the low coe cient of determination (R 2 ) suggesting that factors other than change in date exert greater in uence on air temperature (    In terms of wind, average windspeed varied from 1.22 ms −1 to 2.01 ms −1 , in November and August, respectively. It varied between 18.44% and 29.8% in all the months but the peak occurred in January (see Table 1)

Air temperature
In terms of air temperature (Figure 4a), variability occurred more in December and January than the rest of the months, probably due to the prevalence of Harmattan, which typically dominates the dry season in these months. The Harmattan is a cold dust-laden wind from the Sahara Desert, brought by the Tropical Continental (cT) airmass, that accompanies the hot dry season between December and March (Eludoyin et al., 2014). The air temperature relatively declined from April before rising in September. In general, extreme air temperature condition in the study area is expectedly low (lower than that of the rainfall), as low temperature variability is an important characteristic of areas in the tropics (Jauregui, 1991).
The wavelet transform plot shows two clear distributions of the signals; the upper with low signal disturbance (blue) and the lower part with high disturbance (red band), suggesting relative uniformity in temperature in most part of the time (Figure 4b). Unlike rainfall, the patterns shown in the wavelet results were more regular and predictable, indicating lesser daily, monthly/ seasonal and annual variabilities in temperature than rainfall. The relative uniformity in the air temperature however varied over the months; plots showing the frequency of dry days (days with less than 0.2mm) across the study period showed irregular uctuations over the years (Figure 4c). Expectedly, the dry season months (December -March) recorded more peaks of dry days than the other months. Also, whereas the number of dry days has reduced in most of the months, they (dry days) have increased in March, April, May, July and August (Table 3).   (Table 4a). Table 4   size, land tenure system, cropping method and farm input (Figure 4b). Tree crops occupied 1 -4 ha of land that was acquired through lease, purchase or inheritance. Tuber and cereal crops farms occupied 1-2 ha but while most farms used for tuber were either leased, purchased or inherited, that used for cereals cropping were less likely to have been leased/hired. The importance as attached to a type of crop may in uence type of land allocated to it. For example, perennial crops, especially tree crops are likely to be cultivated on owned (e.g., inherited or purchase) piece of land than leased piece of land while a hired piece of land is more likely to accommodate short-term (biennial, annual or biannual) crops like tuber and leafy vegetables. It is, nonetheless, surprising that land tenure system for cereals (which is essentially an annual or biannual crop) farms were not dominantly hired/leased. Leafy vegetable farms were generally small, and understandably occupied more leased/hired piece of land, probably because they are essentially short-term farming and are largely operated by non-indigenes, female, young people or as a part of other major cropping activities. With respect to cropping methods, dominant method is the mixed cropping system, although few tree crops farmers engage in mono-farming. Mixed cropping or multiple cropping or multi-cropping is the usual practice of growing two or more crops in the same piece of land during one planting season (Abhisek, 2020). In the study area, mixed cropping was practiced, partly for raising income from the farms. In addition, mixed cropping is practiced in the tuber crops farms, mainly to serve as wind breakers, and reduce the impact of wind erosion, among others, or as a precautionary loss supplement as in the case of a 65-year-old key informant who recounted that: 'Weather nowadays is unpredictable. I engaged in mixed farming to have maximum gain and so as not to have the experienced I had in the past. Before, I practiced mono-cropping, cultivating mainly cocoa, until 2006 when was heavy rains of July/August nearly caused me to lose my entire cocoa farm. It was an unforgotten year for me, and even to survive it was terrible for me and my family. Since then I have been engaging in mixed farming for survival so that if such bad climate incidence happens again I will not loss all. It was this type of situation that turned me to a mixed crop farmer.' Seventy-ve (75%) of the farmers apply fertilizers and pesticides to their farms for improved yield.

Effects of extreme weather conditions
Analysis of the perception of selected key informants on the effects of extreme weather conditions is provided in Figures 7(a-c), for rainfall, temperature and wind extremes, respectively. All the key informants perceived that excess (heavy) rainfall, early and late rainfall onset and cessation, as well as irregular rainfall occurrence are extreme rainfall conditions (Figure 7a), and that dry spell, low and high temperature as well as perception of increased temperature is known temperature extreme conditions (Figure 7b). Windy condition such as is also considered an extreme meteorological event in the study area. Most of the farmers and marketers complained of a general shortfall due to the identi ed extreme weather conditions.
Responses from the farm community show a reasonable level of consideration for weather/climate by the farmers. For instance, a male key informant (aged 63 years old) responded to a question requesting if and why they consider weather thus: I study the trend of weather condition and I always prepare ahead, I have been in this farming business for close to 50 years now so I don't joke with weather condition. I know the best weather period for each crop, because I don't have any other work, so I must study the trend of weather very well, though in year 2018 a lot of farmers in this community complained about bad weather conditions, but my son, I have a very high yield output as that of year 2016 and 2017'.
Opinion of key informant indicates that a thorough understanding of the weather condition and capacity to predict the climate is essential for farmers in the area. Conversely, other key informants, who lost 'massively' to a ood event in 2018, appeared to consider a spiritual involvement in the weather conditions. For instance, one of them argued that the hope on miracles to sustain their productivity under extreme climate conditions.

Perception on coping strategies
Speci c extreme climate conditions, the impact and corresponding coping/adaptive strategies, identi ed in the study area, are presented in Table 5. Reported extreme climate conditions include drought, increased heat condition, and delayed or late rainfall. Drought, experienced in terms of loss of yield and land degradation was adapted to by planting of drought resistant varieties of crops, including cassava, banana and cocoyam. Sixty-ve percent of the key informants engaged in planting drought resistance plants to avoid absolute loss in case of drought condition, and 35% only prayed according to their faith. In terms increased heat condition, seeds and seedlings are typically destroyed by heat, leading to poor yield. The farmers also responded to the condition of increased heat the same way they did as for drought resistant crops. However, banana, cocoyam as well as trees such as teak and palm trees are used as 'protective' or 'cover' crops whose broad leaves are used shed the planned crops, including cocoa seedlings. Also, some of the farmers cut leaves of banana and other leafy short trees to protect their cocoa seedlings and young cocoa farms. Furthermore, leafy vegetable farmers usually cultivate around ood plains but they also complained of the destructive impact of mining activities on the oodplains, especially along River Owena. Only about 15% of the farmers whose farmland were around the River Owena oodplain are less affected by the 'change' in weather condition and consequently do not often alter the 'normal' planting season, but adapt by machine-facilitated-irrigation-spray from the river. In general, capacity to respond to any of the identi ed strategies were based on farmer's experience and socio-economic status; the few wealthy farmers tend to respond better by increasing the purchase of fertilizers, pumping machines, pesticides, etc.
Also, transportation network which is vulnerable to ood conditions often requires communal efforts during the ooding season.
Many of the Key informants also revealed that their past experience of delayed/late rainfall has enhanced their preparedness for any of the present and future occurrences. They largely proclaimed to seek divine intervention for preparedness for and coping with the effects of the extreme climatic effects, while decrying the non-performance of the government sector. They alleged total negligence by the government, despite their contribution to the State's economy. When the key informant from the government department of Extension O ce was asked, their response suggested that the representatives rarely visit the farm community for fear of intimidation, poor support and poor understanding of the government plans for the farm community.

Conclusion
Cropping activities (including farming and marketing) in the study area are affected by extreme climate condition and climate variability. It is di cult to project future climatic events based on the experience of farmers alone due to the extreme climate events. Cropping activities are limited by extreme climate scenarios and poor coping strategies in the area. The poor coping strategies appear to have been exacerbated by disconnect with appropriate government agency. Consequently, the study recommends creation of platform for awareness of extreme climatic events, their impacts and enhanced coping strategies among the residents, especially in the rural community, where majority have low socioeconomic status. The study also recommends improved relationship between actors in cropping activities and relevant government agency (Rural Extension workers). At present, evidence from this study revealed sore relationship, and thus has greater impacts on farming activities in the study region. Lastly, improved road links with farm communities is recommended. This will improve the capacity of the people to handle the consequences of extreme events.

Declarations
Ethics approval and consent to participate Ethical approval: Approval to conduct social surveys was obtained through the Obafemi Awolowo University, Ile-Ife, Nigeria Consent to participate: All the participating authors agree to participate in the research. The study area, Iyanfoworogi farm community in southwestern Nigeria  Characteristics of cropping systems in Iyanfoworogi Farm Community Figure 7