Response to climate change in a rain-fed crop production system: insights from maize farmers of western Kenya

It is notable from the results in Fig. 3 that the key adaptation strategy by the farmers in the western region of Kenya was a change of planting decision by either planting early or delaying planting date. This supports the findings of a review study by Kogo et al. (2019c) which established that change of planting dates was one of the major agro-adaption options towards mitigating the impacts of climate change on crop production. According to Lv et al. (2020), adjusting of planting date is one of the strategies used by farmers to maintain or increase crop yields under climate change. However, the major constraint to the shift of planting time is the lack of accurate information on climate forecast to complement indigenous knowledge (Fisher et al., 2015). The adoption of this practice by the farmers is perceived to have low impact on crop production. The factors that positively influence farmers to undertake early or delayed planting were gender of household head and farm size (Table 2). In this case, the heads of households, who were mostly males, were more likely to influence decision on planting time of crops since they are responsible for most of the farm activities and have better understanding of various on-farm crop production practices. In addition, male farmers are more of risk-takers and are likely to adjust their farming practices and adapt to new technologies (Dang et al., 2019).

The influence of farm size on farmers’ decision to plant early before the rains or delay planting can be seen from two perspectives: the first being the fact that farmers with large farms may be forced to plant early so as not to be overwhelmed by planting during the rains, and the other perspective being delayed planting as per early warning information on weather patterns and fear of crop failure in case of planting before reliable rains.

Crop diversification is one of the management options in rain-fed systems that can mitigate against the impacts of climate change and market shocks (Birthal and Hazrana 2019). According to Lin (2011), crop diversification can increase production and improve resilience by reducing vulnerability to pest outbreaks, disease transmission and buffering crop from effects of climate variability and extreme weather events. The use of multiple cropping systems can also influence ground cover, soil erosion, soil chemical properties, pest infestation and potential for carbon sequestration (Waha et al., 2013).

Approximately 63.3% of the farmers interviewed in this study confirmed to be undertaking crop diversification on their farms. The most common diversification strategy (undertaken by 57.6% of the farmers) was intercropping of maize and beans. In the study area, the farmers confirmed that crop diversification was likely to have low effect on crop production under climate change. Age was a variable that positively and significantly influenced farmers to undertake crop diversification. The implication of this is that more elderly household heads were more likely to have high level of experience on the benefits of crop diversification.

Cultivation of early maturing cultivars is among the key adaptation strategies being undertaken by 43.8% of the farmers. The factors that were likely to positively influence farmers’ decision to cultivate early maturing crops were family size and extension trainings. The rationale is that households with large number of members were more likely to grow early maturing crop varieties in more than one season in a year in order to offset production deficit. Additionally, most farming households rely on family labour; thus, with more family members, there is a possibility for adequate labour availability, which can in turn allow completion of farming tasks without hire of labour that increases the production cost during peak seasons. As per Van et al. (2015), household size positively influences adaptive behaviours and uptake of farming technologies. Likewise, extension trainings play an important role in enlightening the farmers on early maturing crop varieties that can be planted during short rainy season. On the other hand, farm size was negatively correlated to cultivation of early maturing crops. This suggests that households with large farm size are not likely to plant early maturing cultivars since they could have sufficient production in one season of the year. On the contrary, farmers with small farm size are more likely to plant early maturing varieties in two seasons of the year under the same plot in order to have adequate produce for their families. This is in agreement with other studies, such as those by Salasya et al. (2007), who noted that late maturing cultivars were likely to extend to more than one season, making it impossible to plant a crop in two seasons on the same piece of land.

Timely planting is a farm management practice aimed at getting the crop planted at optimum planting dates that is largely driven by the prevailing weather conditions (Doerge et al., 2015). As per Sacks et al. (2010), timing of rainfall onset is a key factor that influences planting date. In western Kenya, the onset of long rains ranges from early March to end of April (Mugalavai et al., 2008). This is the period in which the farmers plant maize in order to pollinate and mature between June and August when rains are reliable and avoid the drought stress in September, which can affect grain-filling and overall yields. Approximately 33.8% of the farmers interviewed undertake timely planting as one of the adaptation strategies towards maize production under climate change. However, timely planting was confirmed to have low impact on crop production (average impact score of about 0.69). This is likely to result from poor timing of optimum planting time and possibility of changing weather patterns during crop development that affect overall yields. The regression results show that education level positively influenced farmers’ decision to undertake early planting. This may imply that educated farmers were more observant and better informed than less educated ones about the weather patterns and ultimately, timed rainfall onset as an adaptation decision for optimal crop production under rain-fed conditions.

The use of drought-tolerant varieties was also confirmed to be one of the adaptation options by 28.6% of the respondents. Such varieties are bred to tolerate environmental stresses, including water deficit conditions during seasons of low rainfall (Westengen and Brysting 2014). As per Fisher et al. (2015), the barriers that may influence farmers to use drought-tolerant varieties as an adaptation to climate change were inadequate information, financial constraints, high seed price and limited access to seed. Extension trainings and education level of the household head were positive predictors of adaptation level of the farmer using drought-tolerant varieties. This implies that the farmers that had received extension training and are more educated were more likely to adapt their farming systems to climate variability by use of drought-tolerant varieties. This corroborates a study by Opiyo et al. (2016) that concluded that educated household heads were likely to have better understanding and access to information on adaptation to climate change. On the contrary, households that were headed by elderly persons were more likely to have low-level adaptation to climate variability through the use of drought-tolerant varieties. This is likely because most elderly farmers may be less informed on improved crop varieties and may not be willing to change their conventional cropping systems.

Soil water conservation is one of the farm management practices meant to minimize loss of water through run-off by increasing infiltration rates of the soil surface (Adimassu et al., 2017). This strategy, which is aimed at achieving high rain-use efficiency in crop farming, is among the adaptation measures practiced by 18.6% of the farmers in the study area. The common methods used by farmers to undertake soil water conservation is application of farmyard manure and organic mulching. However, the farmers perceived that the practice had low impact on crop production (average impact score of about 0.39). This implies that full potential of this practice has not been achieved due to other reported constraints such as soil nutrient depletion (Wanyama et al., 2010). Income levels and agricultural extension trainings were the key factors that positively influenced the farmers to undertake soil water conservation. This suggests that wealthier households were likely to have sufficient financial resources to implement soil water conservation measures to improve crop production on their farms. Similarly, farmers who had received extension trainings were likely to understand the need for soil water conservation and would have the knowledge on how to undertake the practice at farm level.

On-farm rainwater harvesting is one of the climate change adaptation strategies whose aim is to collect surface run-off that can be used for supplemental irrigation to mitigate against water deficit during crop growth stages (Odhiambo et al., 2021). In the study area, 7.6% of the farmers interviewed confirmed to be undertaking on-farm rainwater harvesting. However, they reported low impact (impact score of about 0.19) on crop production. This suggests that the households may not be adequately utilizing the harvested rainwater to bridge intra-seasonal dry spells that occur due to unreliable rainfall, and thus were more likely to perceive low benefits in crop production. Extension training and impact perception were some of the factors influencing farmers to undertake rainwater harvesting for irrigation. It is therefore advisable that extension training considers sensitizing farmers on the need to utilize harvested water to irrigate the crops in order to reduce risk of water stress and benefit from improved crop production during rainfall-deficient seasons.

Agroforestry is one of the climate smart adaptation strategies that involve growing of trees in a cropping system (Apuri et al., 2018; Ram et al., 2017; Thorlakson and Neufeldt 2012). From this study, it emerged that agroforestry was one of the adaptation practices undertaken by the least number (2.4%) of farmers interviewed. The farmers also perceived agroforestry to present the lowest impact on crop production. This could also be justified by the low number (3.8%) of farmers that confirmed to have received extension training on agroforestry. Despite the low uptake of this adaptation practice, it is worth noting that some of the ecological benefits associated with agroforestry include improvement of soil and water conservation, soil physical properties and resilience to uncertain windstorm through microclimate buffering (Ajayi et al., 2011; Nguyen et al., 2013; Sileshi et al., 2011; Waha et al., 2013). According to Ram et al. (2017), agroforestry can also serve as a source or sink of reactive nitrogen that can improve soil fertility and subsequently crop performance. In the study, it emerged from regression analysis that there were no noticeable factors that influenced farmers to practice agroforestry. Therefore, considering the enormous benefits of agroforestry practice, it is advisable that the extension service providers consider upscaling awareness of farmers on this practice.