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Improved crop management, such as using improved seeds, applying fertiliser and shifting the planting dates, has high transformative potential for increasing yields. We used process-based and machine learning techniques to evaluate the effectiveness of different crop management strategies for farmers to adapt to climate change. Our analysis found that increasing soil organic carbon in Ethiopia by 20% has positive effects on crop suitability for all crops (increasing suitability between 2-6%, depending on scenario and crop), especially for maize and wheat (see Figure 2). Enhancing organic carbon produces the greatest suitability increases under RCP8.5 for maize, teff and sorghum (ca. 5% suitability increase) and also has positive mitigation effects. However, shifting the growing season forward by four weeks will result in detrimental effects on suitability of the four crops (wheat, teff, maize and sorghum), with suitability losses of up to 10 % projected, and can thus not be recommended as an adaptation strategy.

Using the process-based crop model APSIM, we also evaluated the effect of increasing first basal and then top dressing NPK (Nitrogen, Phosphorous, Potassium) fertiliser on maize yield in Ethiopia for all zones (All) and for zones projected to experience yield losses (Loss). Fertiliser application among smallholders in Ethiopia is estimated to be of rather low intensity, some 30-40% of smallholder farmers apply fertiliser (Spielman, Mekonnen & Alemu, 2011). Applying fertiliser is one means for improving lower and more variable yields due to climate change impacts and can thus also be regarded as an adaptation strategy. Yet, increasing synthetic nitrogen fertiliser application will also lead to higher CO₂ emissions, a thorough assessment of its usefulness for each specific case is thus needed. The results show that increasing basal fertiliser by 50% will increase yields by between 10 and 200% depending on the zone. At national level, an average increase of 56% for all modelled zones under current climatic conditions is projected (Figure 3). 

We also conducted a cost-benefit analysis on one specific crop management strategy, namely a shift in cultivation from maize to sorghum, following the future suitability projections. The analysis shows that in comparison to the no adaptation scenario, the crop switch (adaptation scenario) will be economically beneficial from the year 2041 on (see Figure 4). From then on, the crop switch has a positive return on investment. The following figure shows this development of the net present value (NPV) from 2020 to 2050.

The late break-even point suggests that switching from maize to sorghum cannot be recommended in the near future, but rather in the medium term, once climate change impacts on the crop sector in Ethiopia further materialise. 

In conclusion, improved crop management can generally be recommended for adaptation to climate change in Ethiopia, although some strategies require ex-ante evaluation. Shifting planting dates for instance is not necessarily beneficial, but applying more (organic) fertiliser and investing in improved seeds can generally bring about better yields and higher resilience.

References

• Spielman, D. J., Mekonnen, D. K., and Alemu, D. (2011). Seed, Fertilizer and Agricultural Extension in Ethiopia. IFPRI, ESSP II Working Paper 20.

Irrigation can help smallholder farmers to compensate for the negative impacts of erratic and insufficient precipitation and significantly stabilise agricultural production (Woldemariam & Gecho, 2017). More specifically, it can raise agricultural production, allow for greater cropping intensity and crop diversity (i.e. higher-value crops), and lengthen agricultural seasons (Awulachew, 2010; Woldemariam & Gecho, 2017). Irrigation thus serves three main adaptive purposes: 1) Increasing yields by supplying water needed, 2) reducing risk due to a more constant water supply and 3) enabling multiple harvests and cultivation of high-value cash crops, as irrigation supplies water in the dry season. 

Currently, irrigation is not wide-spread yet in Ethiopia (estimates range between 2-3 % of agricultural land, with water coming from Ethiopia’s ample surface water resources), with considerable potential to upscale its usage. Stakeholder consultations, interviews, the expert survey conducted and document analysis made clear that irrigation is a key adaptation priority in Ethiopia. The Ethiopian government is aiming to transform its agricultural sector from a subsistence mode to a market-oriented one. The potential for irrigation in Ethiopia is enormous, as it has ample surface water and groundwater resources on the one hand and land suitable for irrigation on the other hand (Woldemariam & Gecho, 2017). Twelve major river basins lie in Ethiopia, which form four main drainage systems. However, there is high spatial and temporal variability (FAO, 2005; Worqlul et al., 2015). According to various studies, there is sufficient water in Ethiopia to develop around 4.5 million hectares of agricultural land that could be irrigated through pump, gravity, pressure, underground water, water harvesting and other mechanisms (Makombe et al., 2011; Woldemariam & Gecho, 2017; Worqlul et al., 2017). The hydrological analysis in Chapter 2 also confirms this and projects ample water available for irrigation in the future.

A cost-benefit analysis of switching from rainfed maize production to irrigated maize production showed that adopting irrigation is beneficial for Ethiopian farmers. Over time, irrigation has a positive return on investment (see Figure 1).  

Yet, irrigation requires a considerable investment and only becomes profitable after some years, depending on the type of irrigation system and the farm location. Institutional support is usually required and care has to be taken to avoid potential maladaptive outcomes from irrigation. Table 1 gives an overview of potential co-benefits and maladaptive outcomes from adaptation in Ethiopia. 

Constraints to adaptation uptake in Ethiopia include weak institutional capacity and lack of physical infrastructures, such as pumps, conveyance structures and storage facilities, but also access to electricity in rural areas (Awulachew, 2010; FAO, 2015b; Worqlul et al., 2017).

Overall, irrigation is an important adaptation strategy in Ethiopia with large potential to transform the agricultural sector and increase yields. Government support and careful policy design is needed to make implementation succeed.

Note to the reader: This evaluation is only to be viewed as a careful model‐based and expert assessment, which can by no means replace a thorough analysis for specific project design and local implementation planning. It gives an indication of the overall feasibility and suitability of the selected adaptation strategies in Ethiopia. Actual selection of adaptation strategies, however, should always be based on specific needs and interests of local communities.

References

• Awulachew, S. B. (2010). Irrigation potential in Ethiopia Constraints and opportunities for enhancing Irrigation potential in Ethiopia Constraints and opportunities for enhancing the system International Water Management Institute Teklu Erkossa and Regassa E . Namara. IWMI Research Report.
• FAO (UN Food and Agriculture Organization), (2005). Irrigation in Africa in figures – AQUASTAT Survey 2005, 1–14.
• FAO, (2015b): Analysis of price incentives for red sorghum in Ethiopia for the time period 2005-2012. Rome: FAO.
• Makombe, G., Namara, R., Hagos, F., Awulachew, S. B., Ayana, M., & Bossio, D. (2011). A com-parative analysis of the technical efficiency of rain-fed and smallholder irrigation in Ethiopia. IWMI Working Papers (Vol. 143). https://doi.org/10.5337/2011.202.
• Woldemariam, P., & Gecho, Y. (2017). Deter-minants of Small-Scale Irrigation Use: The Case of Boloso Sore District, Wolaita Zone, Southern Ethiopia. American Journal of Agri-culture and Forestry, 5(3), 49.
• Worqlul, A. W., Collick, A. S., Rossiter, D. G., Langan, S., & Steenhuis, T. S. (2015). Assess-ment of surface water irrigation potential in the Ethiopian highlands: The Lake Tana Basin. Catena, 129, 76–85. https://doi.org/10.1016/ j.catena.2015.02.020.
• Worqlul, A. W., Jeong, J., Dile, Y. T., Osorio, J., Schmitter, P., Gerik, T., … Clark, N. (2017). Assessing potential land suitable for surface irrigation using groundwater in Ethiopia. Applied Geography, 85, 1–13.

Smallholder farmers in the global South mostly use traditional crop varieties, which can be vulnerable to climate impacts such as droughts, floods or also diseases. In order to improve the resilience of crops to climatic shocks and to raise yields, improved crop varieties are bred from traditional varieties. The process of breeding is lengthy and costly, but once better varieties are released and used, they can substantially improve agricultural yields and resilience, depending on their specific characteristics. As such, breeding improved varieties is an institution-led approach, since it requires resources and time, which smallholder farmers most often do not have.

Improved crop varieties can offer a number of interesting development co-benefits, especially linked to increased agricultural production and income. However, they are expensive to develop:  a multitude of factors will determine prices of the seeds, such as demand, scale of adoption, and – for farmers – potential government subsidies

A number of improved crop varieties already exist or are being developed in Ghana, for instance for maize, rice, cassava and cocoa, with sought-after properties being drought resistance, flood resistance and achievement of high yields. Maize appears to be the focus of breeding efforts in Ghana, as several publications (e.g. Alhassan, Salifu & Adebanji, 2016; Danso-Abbeam et al., 2017) and the number of active breeders for maize (10 out of 26) confirm (Mabaya et al., 2017).

An analysis conducted using the biophysical crop model APSIM shows that improved maize varieties indeed hold large potential for increasing yields under climate change (Figure 3). However, the size of the effect and sometimes even direction depends on the location, with the impact in different districts in Ghana differing considerably. Compared to no adaptation and other agronomic adaptation measures such as applying manure or delaying the sowing date, a carefully selected improved variety may indeed have a larger impact on increasing maize yields.

Another analysis conducted with machine-learning based crop suitability models shows how generally the effect of agronomic adaptation strategies varies considerably across crops. While maize and cassava appear to benefit from many agronomic adaptation strategies under climate change, for sorghum this is much more the case under the high-emission climate scenario (RCP8.5) and for groundnut, none of the adaptation strategies proposed has a positive effect.

Agronomic adaptation strategies and the use of improved seeds should thus be carefully evaluated for each specific region, crop and climate impact scenario. Nonetheless, improved crop varieties are seen as a transformative tool for buffering climate impacts in Ghanaian agriculture. Breeding is costly and time intensive, but where improved varieties already exist, they can contribute importantly to a higher agricultural output.

References

• Alhassan, A., Salifu, H., & Adebanji, A. O., (2016). Discriminant analysis of farmers’ adoption of improved maize varieties in Wa Municipality, Upper West Region of Ghana. SpringerPlus, 5(1).
• Danso-Abbeam, G., Bosiako, J. A., Ehiakpor, D. S., & Mabe, F. N., (2017). Adoption of improved maize variety among farm households in the northern region of Ghana. Cogent Economics and Finance, 5(1), 1–14.
• Mabaya, E., Adzivor, S. Y., Wobil, J., & Mugoya, M., (2017). Ghana Brief 2017 – The African Seed Access Index, (December).

Rainwater harvesting (RWH) allows storing irrigation water for critical times in the growing period of otherwise rain-fed crops. It is also a promising practice for reducing costs for irrigation uptake as its installation is considerably cheaper than building groundwater irrigation infrastructure.

In Ghana, limited evidence on the use and potential of RWH for small-scale irrigation systems exists. Even though Ghana has abundant water resources for irrigation, its uptake is very low. RWH can provide a cost-efficient alternative to irrigation installment and is notably a strategy with usage potential at different scales. It is particularly well suited to be coupled with farm-level horticulture production, either for additional income from vegetable sales or satisfying changing demands in household consumption (for Sub-Saharan Africa as a whole, see e.g. OECD & FAO, 2016). This could also yield nutritional and thus health benefits, with vegetables enriching otherwise staple-based diets in Ghana. A combination with conservation agriculture techniques can be particularly useful, with further improvements in soil water storage capacity enhancing the water use efficiency of RWH.

In addition, RWH has the potential to deliver gender co-benefits. Since it is usually women who are in charge of fetching water and who engage in backyard vegetable farming, collecting rainwater could save women time, making time for other activities and enabling additional farming activities.

Rainwater harvesting and small-scale irrigation are a good alternative for action at smallholder level, with simple installation techniques proving less difficult to implement, maintain and refinance as compared to large-scale irrigation systems.

Thus, RWH is a promising adaptation strategy meeting local interest in Ghana. It can be implemented by farmers autonomously and decrease dependency on precipitation.

References

• OECD/FAO, (2016). Agriculture in Sub-Saharan Africa: Prospects and challenges for the next decade, in OECD-FAO Agricultural Outlook 2016-2025, OECD Publishing, Paris. https://dx.doi.org/10.1787/agr_outlook-2016-5-en.

In areas short of precipitation, irrigation can be a key strategy to enable plant growth and increase yields. Water can be drawn from different sources, such as groundwater, surface water and in some countries even desalinated seawater, to enable a better growth of plants. Irrigation schemes at smaller scale can be initiated and implemented by farmers themselves, but for larger irrigation installations, technical agencies and extension officers play an important role.

As of yet, irrigation is not widely spread in Ghana, with only an estimated 1.6% of the area with a respective potential actually being irrigated (Mendes, Paglietti & Jackson, 2014), mostly for rice and horticulture cultivation (Namara et al., 2011). This limited uptake implies that further installation of irrigation schemes is possible and could increase Ghana’s agricultural production. However, this may incur high costs and technically challenging installation and maintenance. As a climate change adaptation strategy, the case for irrigation depends on the climate scenario, with the North of Ghana projected to see less rainfall under future climate change. However, as a measure to intensify agricultural production and enable multiple harvests, irrigation can also be considered useful today, where water is available for agricultural use.

Figure 2 shows the net value of maize production in the whole of Ghana under different irrigation scenarios, reflecting the varying costs that different irrigation techniques and installations incur. As can be seen from the comparison with the baseline scenario and the scenario under climate change, not all irrigation scenarios are able to offset the losses projected under climate change.

In sum, while irrigation has the potential to increase agricultural production in Ghana, it is also a costly strategy, often requiring institutional support for implementation and maintenance.

References

• Mendes, D.M, Paglietti, L. & Jackson, D., (2014). Ghana: Irrigation market brief. Food and Agri-culture Organization of the United Nations. Rome.
• Namara, R., Horowitz, L., Nyamadi, B. & Barry, B., (2011). Irrigation Development in Ghana: Past experiences, emerging opportunities, and future directions, International Food Policy Research Institute, GSSP Working Paper No. 27, Ghana Strategy Support Program, Accra.

Effective post-harvest management is crucial to avoid food loss along the value chain. Investments in scaling technologies for improved post-harvest management have high potential for reducing crop losses, also and especially under climate change. With climate change altering growing and harvesting seasons, post-harvest management is important to cope with increased uncertainty. It is a risk-reducing strategy that lowers the vulnerability of crop production to climate impacts. Next to main staple crops such as maize and beans, post-harvest loss (PHL) of easily perishable horticulture crops could be avoided. Numerous effective and low-cost technologies exist that can prevent or reduce PHL.

Ghana’s NDC Implementation and Investment plan lists post-harvest management as a priority for adapting agriculture to climate change, with interviews confirming wide-spread interest in such strategies. A concrete post-harvest technology with promising results in the context of maize production in Ghana have been so-called PICS bags (Purdue Improved Cowpea Storage): simple and affordable yet effective hermetic storage bags originally developed for storing cowpea. Implementation of improved post-harvest management strategies can be recommended across the country as a low-hanging fruit, since better post-harvest management can increase agricultural production considerably.

Furthermore, as the economic analysis confirmed, most post-harvest management measures are rather low cost interventions, with most intervention types being “no regret” strategies because even in the absence of climate change, the improvement in crop handling will lead to lower crop losses and higher agricultural output, being economically sensible. Figure 1 shows the net value of maize production under different post-harvest management scenarios, compared to scenarios of maize production without adaptation – both with (CC) and without climate change (BAS). Except for the highest cost scenario (MAX), all other PHM scenarios do not only make up for the maize losses under climate change, but are also able to surpass maize production under the baseline scenario (without climate change and without adaptation). This shows their high economic viability.

Overall, post-harvest management strategies have considerable potential in Ghana and, being an often low-cost and no-regret strategy, can be recommended for wider implementation.

While most adaptation strategies seek to minimize risks stemming from climate change, not all risks can be eliminated. Weather perils such as droughts, storms or erratic precipitation represent so-called systemic risks that go beyond the farmers’ coping ability. Thus, mechanisms are needed that distribute residual risks to avoid that certain groups or individuals lose their livelihoods. One such risk transfer solution is crop insurance, which allows farmers to insure their crop yields against weather-induced losses. While insurance usually is based on indemnity assessment, this model is problematic for smallholder farmers due to the high transaction costs which insurance schemes usually entail. Thus, a more suitable approach for smallholder farmers are weather index-based insurances (WII), a scheme that uses a weather index, such as precipitation, to determine a payout. Alternative index-based insurance schemes can also be useful, such as area-yield index insurance.

Generally, insurance schemes are rather costly adaptation strategies, at least when considering the overall costs and with progressing climate change increasing the overall risk to the agricultural sector. However, insurance schemes have an important role to play for securing livelihoods: They can stabilize farm incomes and can prove to be very cost-effective for farmers when a hazard occurs.

According to the Ghana Agricultural Insurance Pool (GAIP), area-yield index insurance (AYII) as an alternative to WII has shown the biggest potential for smallholder farmers in Ghana as of yet. GAIP is a pioneer in implementing AYII in Ghana, insuring since 2011 successfully some 3000 – 4000 smallholder farmers’ cereal crops^[1] on over 18,000 acres of land. In 2017, GAIP made payouts to nearly half its insured parties.

Although AYII is a promising development, farmers’ uptake of AYII in Ghana remains limited. Balmalssaka et al. (2016), who examined the willingness of farmers in northern Ghana to participate in insurance schemes, found access to credit as well as education and experience with insurance to be important factors determining farmers’ engagement with crop insurance (Balmalssaka et al., 2016).

This indicates the need for additional incentives or financial support for taking out insurance, underlined also by Aidoo et al. (2014) who determined farmers’ willingness to pay for crop insurance in one municipality in Ghana. He concluded there was a need for government subsidies to implement it in the country (Aidoo et al., 2014). While subsidies are one strategy, experts also suggested to bundle insurance with inputs, where possible, to increase uptake.

Overall, crop insurance is a promising strategy for transferring climate risk also in Ghana. There is high interest in Ghana and demand-based roll-out of insurance pilots can be recommended. However, careful design is crucial to ensure affordability and financial sustainability.

[1] The main insured crops are: maize, sorghum, millet and groundnut.

References

• Aidoo, R., James, O., Prosper, W., & Awunyo-Vitor, D., (2014). Prospects of crop insurance as a risk management tool among arable crop farmers in Ghana. Asian Economic and Financial Review, 4(3), 341–354.
• Balmalssaka, Y., Wumbei, B. L., Buckner, J., & Nartey, R. Y., (2016). Willingness to participate in the market for crop drought index insurance among farmers in Ghana. African Journal of Agricultural Research, Vol. 11(14), 1257–1265.